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The steelmaking–continuous casting process (SCCP) is a complex manufacturing process which exhibits the distinct features of process manufacturing. The SCCP involves a variety of production elements, such as multiple process routes, a wide array of smelting and auxiliary devices, and a variety of raw and auxiliary materials. The production-simulation of SCCP holds a natural advantage in being able to accurately depict the intricate production behavior involved, and this serves as a crucial tool for optimizing the production operation of the SCCP. This paper thoroughly considers the various production elements involved in the SCCP, such as the fluctuation of the converter smelting cycle, fluctuation of heat weight, and ladle operation. Based on the Plant Simulation software platform, a dynamic simulation model of the SCCP is established and detailed descriptions are provided regarding the design of an SCCP using dynamic-operation rules. Additionally, a dynamic operational control program for the SCCP is developed using the SimTalk language, one which ensures the continuous operation of the caster in the SCCP, using the discrete simulation platform. The effectiveness of the proposed dynamic simulation model is verified by the total completion time of the production plan, the transfer time of the heat among the different processes, and the frequency of ladle turnover. The simulation's results indicate that the dynamic simulation model has a satisfactory effect in simulating the actual production process. On this basis, the application effects of different schedules are compared and analyzed. Compared with a heuristic schedule, the optimized schedule based on the "furnace–machine coordinating" mode reduces the weighted value of total completion time by 8.7 min, reduces the weighted value of transfer waiting time by 45.5 min, and the number of rescheduling times is also reduced, demonstrating a better application effect and verifying the optimizing effect of the "furnace–machine coordinating" mode on the schedule. [ABSTRACT FROM AUTHOR]

The paper presents a case study in which a dynamic simulation modeling (DSM) calculation was carried out to assess the energy performance of a building in Giroc, a locality adjacent to the city of Timișoara, using the VABI Elements software. The characteristics were determined based on which the HVAC equipment was selected. [ABSTRACT FROM AUTHOR]

Mathematical modeling of bearing faults, worn tool holder taper contact interface, and unbalance are presented and integrated into a digital dynamic model of spindles in Part I of this paper. These faults lead to changes in preload and dynamic stiffness over time, consequently resulting in observable vibrations. This paper predicts the vibrations of a spindle at a particular measurement location by simulating the presence of a specific fault or multiple faults during spindle rotation. The vibration spectra generated by the digital spindle model at the spindle speed and its harmonics, the changes in the natural frequencies, and dynamic stiffnesses are correlated to faults with experimental validations. The simulated vibration spectrums are later used in training an artificial neural network for fault condition monitoring presented in Part III of the paper. [ABSTRACT FROM AUTHOR]

Pulsed water jet technology has broad application prospects in the field of rock breaking. The pressurized pulsed water jet (PPWJ) is a new type of pulsed jet that offers high-amplitude pressurization, variable pulse pressure and frequency, and a high energy usage rate. To achieve a more destructive and powerful pulsed water jet, a dynamic simulation model of the device was established by using the AMESim software (v1400) based on the operational principle of PPWJs, and the simulation model was validated against the experimental results. The relationships between the key structural parameters of the PPWJ device and the pulse parameters were quantitatively investigated. The pulse pressure and frequency can be increased by appropriately increasing the nozzle diameter or boost ratio, and the pulse pressure will drop if the nozzle diameter or boost ratio exceeds a threshold value. Increasing the maximum displacement or action area of the piston will increase pulse length while decreasing pulse frequency; a proper match of the maximum displacement or action area of the piston will assure pulse peak pressure. The maximum outer diameter of the piston only affects the pulse frequency. The key structural parameters of the device were optimized on that foundation. Compared to the original device, the optimized device resulted in an increase in pulse frequency and jet output energy, leading to larger diameter and volume of erosion pits at the same stand-off distance and erosion time. The findings of this study offer valuable scientific insights for achieving efficient rock breaking with PPWJ. [ABSTRACT FROM AUTHOR]

The cruise industry is obliged by economic and environmental initiatives to pursue fuel-efficient solutions and lower ship exhaust emissions. The medium voltage DC (MVDC) distribution with intelligent power management has become a concept for next-generation onboard power systems as its energy-saving feature is to eliminate the frequency constraint and simultaneously optimize engine loads and speed in response to load variations. The incentive for this transition lies on one hand in the fuel efficiency consideration and the reduction of power losses from serial conversion stages. On the other hand, the DC-based technology has been conceived as high-power density design, thus significantly increasing the payload. This study investigates such potential benefits focusing exclusively on large cruise vessels. A highly representative model of the integrated power platform that incorporates all dynamic interactions from the ship hull and essential machinery typically installed on board cruise ships is proposed. The power management strategy also takes account of actual sea conditions and real-time operation requirements. The simulation results demonstrate that the optimization-based MVDC system is able to maximize the opportunity of search agents in finding optimum fuel efficiency areas throughout the scenario time. An analysis of the system structure weight and space reduction of the MVDC architecture is also performed through the utilization of more compact electrical distribution devices and very high power-dense combustion turbines. [ABSTRACT FROM AUTHOR]

This research paper presents a comprehensive investigation aimed at enhancing the 2G bioethanol production process through the implementation of a dynamic process simulator. The simulator, developed using the Julia programming language, enables the prediction of acid hydrolysis behaviour by manipulating critical variables, including liquid–solid ratio (LSR), acid concentration (CA), and processing time (t). Through meticulous simulations and subsequent experimental validation, optimal operating conditions were revealed, with an H2SO4 concentration of 2% v/v, a LSR of 4% v/w, and 60‐min processing time at 121.1°C. This configuration led to remarkable outcomes, including a xylose concentration of 47.45 g L−1 and an 87.4% hemicellulose removal percentage. Moreover, the simulator unveiled the adverse influence of low LSR values on xylose production and the generation of degradation products. The recalibration of kinetic parameters, guided by experimental data, further fine‐tuned the simulator's predictive accuracy. Overall, this study underscores the potential of the simulator in optimizing various raw materials and presents a promising avenue for advancing 2G bioethanol industry practices. [ABSTRACT FROM AUTHOR]

Aiming at the difficulty of dynamic modeling of a hybrid robotic arm, a dynamic model system of industrial robotic arm based on Simscape Multibody was established with the MG400 robotic arm as the research object, which combines the motion control and data acquisition modules. The model is dynamically visualized and provides a convenient platform for studying the control algorithm of the robot arm. In response to the issues of sluggish speed and substantial position error in robot trajectory tracking control of a traditional controller, a variable gain iterative learning control methodology was designed. The robot arm control system model was employed to corroborate the trajectory tracking control under the stipulated target trajectory. The empirical outcomes indicate that in comparison to the traditional controller and the fixed-gain iterative learning controller, the variable-gain iterative learning controller can regulate the robot end trajectory more precisely, with swift tracking speed and accurate tracking posture, demonstrating commendable feasibility and portability. It offers an open-source research and development platform for the dynamic modeling of robot arm and a potent solution for the control strategy of robot arm. [ABSTRACT FROM AUTHOR]

This research introduces the NeuRaiSya (Neural Railway System Application), an innovative railway signaling system integrating deep learning for passenger analysis. The objectives of this research are to simulate the NeuRaiSya and evaluate its effectiveness using the GreatSPN tool (graphical editor for Petri nets). GreatSPN facilitates evaluations of system behavior, ensuring safety and efficiency. Five models were designed and simulated using the Petri nets model, including the Dynamics of Train Departure model, Train Operations with Passenger Counting model, Timestamp Data Collection model, Train Speed and Location model, and Train Related-Issues model. Through simulations and modeling using Petri nets, the study demonstrates the feasibility of the proposed NeuRaiSya system. The results highlight its potential in enhancing railway operations, ensuring passenger safety, and maintaining service quality amidst the evolving railway landscape in the Philippines. [ABSTRACT FROM AUTHOR]

Radial piston motors are executive components in hydraulic systems, tasked with providing appropriate torque and speed according to load requirements in practical applications. The purpose of this study is to predict the output torque of radial piston hydraulic motors and confirm their suitable operating conditions. Efficiency determination experiments were conducted on physical models, yielding thirty sets of performance data. Torque (output torque) and mechanical efficiency from the experimental data were selected as prediction targets and fitted using two methods: multiple linear regression and neural networks. A dynamic simulation model was built using Adams2020 software to obtain theoretical torque values, enabling the verification of the alignment between the predicted values and simulation results. The results indicate that the error between the theoretical torque of the dynamic model and the physical experiments is 1.9%, with the error of the neural network predictions being within 2%. The dynamic simulation model can yield highly accurate theoretical torque values, providing a reference for the external load of hydraulic motors; additionally, neural networks offer accurate predictions of output torque, thus reducing experimental testing costs. [ABSTRACT FROM AUTHOR]

Introduction: Targeted herbicide application refers to precise application of herbicides in weed-infested areas according to the location and density of farmland weeds. At present, targeted herbicide application in wheat fields generally faces problems including the low herbicide adhesion rate, leading to omission and excessive loss of herbicides. Methods: To solve these problems, changes in the impact force of herbicide and the weed leaves in the operation process of a spraying system were studied from the interaction between weeds and herbicides applied. A dynamic model of weed leaves was established. On this basis, the research indicated that the herbicide adhesion rate is highest under spraying pressure of 0.4 MPa and flow rate of 0.011 kg/s when the spray height is 300 mm. To study the dynamic deformation of weed leaves and the distribution of liquid herbicides in the external flow field under weed-herbicide interaction, a dynamic simulation model of herbicide application was built using the finite element method. Results and Discussion: The results show that when the spray height is 300 mm, the maximum weed leaf deformation index (LDI) is 0.43 and the velocity in the external flow field is 0 m/s under spraying pressure of 0.4 MPa and flow rate of 0.011 kg/s. This finding indicates that the herbicide is not splashed elsewhere and the turbulence intensity in the weed area is 2%, implying steady flow of the herbicide, most of which can be retained on weed leaves. Field test results of application quality of the herbicide show that the maximum LDI is 0.41 and the coverage of the herbicide in the sheltered area below the leaves is 19.02% when the spraying pressure is 0.4 MPa, flow rate is 0.011 kg/s, and spray height is 300 mm. This solves the problem of a low rate of utilization of herbicides because the herbicide passes through weed plants, and achieves the precision herbicide application in wheat fields. [ABSTRACT FROM AUTHOR]

The Cucumber Productivity Simulation Model (CPSM) was developed to precisely predict the dynamic process of cucumber productivity in a solar greenhouse. This research conducted a variety of sowing experiments and collected data on cucumber productivity and meteorological conditions from 2013 to 2015 and 2018 to 2020. Employing the principles of least squares, the relationship between cucumber productivity indicators and effective accumulated temperature (EAT) was fitted, determining key crop parameters and constructing the CPSM. Validation of the model was conducted using independent experimental data, evaluating its simulation accuracy. The results indicate that (1) CPSM can dynamically and meticulously simulate the formation process of different productivity indicators in cucumber. Normalized root mean square errors (NRMSE) ranged from 0.44% to 19.64%, and mean relative errors (MRE) ranged from 0.31% to 17.23% across different productivity indicator models. The models for organ water content, maximum root length, specific leaf area, and organ fresh weight distribution index demonstrated high simulation accuracy, while others showed relatively high accuracy. (2) Simulation accuracy varied with indicators and varieties. 19 indicators (34.55%) exhibited high simulation accuracy and 30 indicators (54.55%) showed relatively high accuracy. The JY35 variety (10.44 ± 8.49%) outperformed the JS206 variety (13.44 ± 8.50%) in terms of simulation accuracy. The JY35 variety had 39 superior productivity indicators (70.91%) while the JS206 variety had sixteen (29.09%). CPSM utilizes easily accessible temperature data as its input, allowing for precise and detailed simulation of productivity indicators for cucumber production in solar greenhouses. This research lays a theoretical foundation and provides technical support for guiding intelligent production management, efficient utilization of agricultural resources, and climate change productivity assessment in solar greenhouse cucumber production. [ABSTRACT FROM AUTHOR]

Ancient masonry pagodas hold significant scientific, historical, and cultural importance. However, due to the complexity of masonry materials, structures, and boundary conditions, establishing finite element static and dynamic models for ancient masonry pagodas is highly challenging. This study aimed to explore the dynamic characteristics and finite element numerical simulation methods of ancient masonry pagodas in Yongzhou, Hunan province. It focused on the Huilong Pagoda in Yongzhou, where in situ test experiments under natural excitation are conducted. The SSI and NExT-ERA methods were employed to determine the ancient pagoda's natural frequencies, vibration patterns, and damping ratios, and to validate the NExT-ERA method. The macroscopic numerical model of the Huilong Pagoda was calibrated using measured results. Subsequently, the NExT-ERA identification results were compared and analyzed with the numerical simulation results of the dynamic characteristics. The results indicate that the first three orders of natural frequencies for the ancient pagoda in the east–west direction are 1.937 Hz, 6.802 Hz, and 21.361 Hz, respectively. Similarly, the first three orders of natural frequencies in the north–south direction are 1.935 Hz, 7.439 Hz, and 21.398 Hz. The results obtained from both methods revealed that the overall structural damping ratio ranges from 0.21% to 2.89%. The numerical model was analyzed using ANSYS, and the first three orders of natural frequencies obtained were highly consistent with the measured values, exhibiting a maximum relative error of 8.54%. The numerical simulation method developed in this study can effectively simulate masonry pagodas. [ABSTRACT FROM AUTHOR]

The development of accurate dynamic battery pack models for electric vehicles (EVs) is critical for the ongoing electrification of the global automotive vehicle fleet, as the battery is a key element in the energy performance of an EV powertrain system. The equivalent circuit model (ECM) technique at the cell level is commonly employed for this purpose, offering a balance of accuracy and efficiency in representing battery operation within the broader powertrain system. In this study, a second-order ECM model of a battery cell has been developed to ensure high accuracy and performance. Modelica, an acausal and object-oriented equation-based modeling language, has been used for its advantageous features, including the development of extendable, modifiable, modular, and reusable models. Parameter lookup tables at multiple levels of state of charge (SoC), extracted from lithium-ion (Li-ion) battery cells with four different commonly used cathode materials, have been utilized. This approach allows for the representation of the battery systems that are used in a wide range of commercial EV applications. To verify the model, an integrated EV model is developed, and the simulation results of the US Environmental Protection Agency Federal Test Procedure (FTP-75) driving cycle have been compared with an equivalent application in MATLAB Simulink. The findings demonstrate a close match between the results obtained from both models across different system points. Specifically, the maximum vehicle velocity deviation during the cycle reaches 1.22 km/h, 8.2% lower than the corresponding value of the reference application. The maximum deviation of SoC is limited to 0.06%, and the maximum value of relative voltage deviation is 1.49%. The verified model enables the exploration of multiple potential architecture configurations for EV powertrains using Modelica. [ABSTRACT FROM AUTHOR]

Coal-resource-based cities, as one of the important types of typical resource-based cities in China, have strong characteristics of instability, sensitivity, and fragility, exhibiting a series of vulnerability features of the human-land system. Previous studies have lacked a deeper investigation into the vulnerability of such cities from the perspective of coupling feedback mechanisms among various elements or subsystems. This paper adopts Bohle et al.'s "Dual Structure Model" of vulnerability to establish an indicator system for vulnerability warning in coal-resource-based cities. Using Fushun City as a sample, a dynamic simulation model of vulnerability in coal-resource-based cities is constructed based on system dynamics for warning simulation calculations, analyzing the evolution trend of vulnerability in Fushun City from 2010 to 2022. The results show the following: (1) from 2010 to 2022, the urban vulnerability of Fushun City transitioned from a medium warning level to a relatively safe level, showing a trend of annual reduction and improvement, undergoing three development stages of significant reduction, fluctuation stabilization, and slight rebound. (2) Due to the causal relationships among various elements within the vulnerability subsystems of Fushun City, differences exist in the contribution levels of vulnerability subsystems during the period 2010–2022, under the combined effects of sensitivity and adaptability factors. The contribution rate of the natural subsystem was the highest from 2010 to 2014, while, from 2016 to 2019, urban vulnerability began to shift towards an economically and socially dominant type. Influenced by the pandemic, Fushun City's overall vulnerability has shown an upward trend since 2020 compared to the previous stage. Finally, specific policy suggestions are proposed for Fushun City to cope with vulnerability changes based on the analysis results, providing a theoretical basis for achieving sustainable development in such coal-resource-based cities. [ABSTRACT FROM AUTHOR]

Shimmy is one of the important factors affecting the ride comfort and lateral stability of straddle-type monorail vehicles with single-axle bogies (SMVS). To obtain the main parameters affecting SMVS shimmy, a global sensitivity analysis strategy for SMVS shimmy is proposed. The shimmy response surface model is constructed, and the sensitivity analysis of the shimmy response surface model is carried out by the Sobol method. Based on this, the shimmy factor model of SMVS is established by factor analysis method. A novel SMVS shimmy analysis method based on factor model is proposed. The shimmy factor model is verified by the dynamic model of SMVS. The results show that 11 main factors affecting the shimmy are obtained by sensitivity analysis. Through the dimension reduction technology of factor analysis, four main factors affecting SMVS shimmy are extracted. The complex coupling relationship between the shimmy factors of SMVS is revealed. The established shimmy factor model can effectively analyse the shimmy state of SMVS, and the dynamic simulation results also show consistency. This study not only proposes a new perspective to understand the SMVS shimmy mechanism, but also provides the foundation for further optimal design of monorail vehicle stability. [ABSTRACT FROM AUTHOR]

In recent decades, the evolution and advancement of automotive technology have played a crucial role in enhancing the safety and security of drivers and passengers. One prominent technology that significantly contributes to vehicle safety is the Anti-lock Braking System (ABS), which notably improves safety during braking, reduces braking distances, and enhances vehicle control across various road surface conditions. This paper introduces an innovative real-time algorithm aimed at improving the performance of ABS systems, leveraging practical data instead of complex mathematical modeling. Unlike traditional modeling approaches that rely on half car model and dynamic tire simulations, this study utilizes actual wheel data to develop and optimize the algorithms. This approach enhances the sensitivity and adaptability of the algorithm to real-world road changes and varying operational conditions. Furthermore, the method effectively addresses and analyzes the phenomena of Jump and Split, which have not been specifically tackled in other studies. Validated through both analytical and empirical models, this approach provides high accuracy in estimating acceleration in scenarios where accelerometer sensors are unavailable. It offers precise responses under varying braking conditions. Simulation results of the algorithm using practical test data indicate that it achieves approximately 49.1% faster detection times compared to other algorithms, offering significant advantages such as reduced braking distances and lower computational costs. [ABSTRACT FROM AUTHOR]

As an advanced design technology for large wide-body airliners, the three-dimensional (3D) dual-sidestay (DSS) landing gear retraction mechanism can share the ground loads transferred by the landing gear, reducing the load on the wings. However, the addition of a strut system may significantly impact the synchronous locking performance of the landing gear with extremely high sensitivity. To study this impact pattern, both a rigid–flexible-coupling dynamic model of DSS landing gear considering joint clearance and node deviation and a synchronous locking test platform are established in this paper, and the simulation model is validated through the experimental results. Based on the simulation model, this paper conducts a detailed study on the influence of different node deviations and joint clearance on the synchronous locking dynamic characteristics of the DSS landing gear. The results show that, as the node deviation increases, the locking of the lock link gradually lags until one side cannot be fully locked; the structural clearance has a smaller impact on the synchronous locking of the landing gear. The feasible region of parameters satisfying the synchronous locking condition is given, which provides a basis and support for the parameter design of dual-sidestay retraction mechanisms. [ABSTRACT FROM AUTHOR]

Reductions of carbon dioxide emissions from the building sector are mandatory for climate protection. This calls for both a reduction of the construction material and energy as well as a reduction of the operational energy. Against this background, a novel facade-integrated adsorption system for solar cooling of lightweight buildings is proposed and theoretically investigated in this work. For this purpose, a detailed simulation model is developed to analyze both the processes in the single components as well as the overall system behavior. The proposed system consists of the three components adsorber, condenser and evaporator, which are connected vacuum-tight and are coupled by vapor transfer. The simulation results of a defined reference case yield cooling rates of 54   W per installed square meter of adsorber facade. The cooling power can be maintained for 12 h, confirming the applicability of the proposed system. Furthermore, a comprehensive parametric study is carried out in order to identify an optimum set of parameter values for maximum cooling rate under the assumed conditions. The results reveal that controlled constant cooling rates of 105   W per square meter of adsorber facade can be reached and a maximum peak power of 145   W per square meter of adsorber facade is possible. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to present numerical simulations for a series of flight processes for the postlaunching stage of the "balloon-borne UAV system." It includes the balloon further ascent motion after airborne launching. In terms of unmanned aerial vehicles (UAVs), the tailspin state and the charge-out process with an anti-tailspin parachute-assisted suspending are analyzed. Then, the authors conduct trajectory optimization simulations for the long-distance gliding process. Design/methodology/approach: The balloon kinematics model and the parachute Kane multibody dynamic model are established. Using steady-state tailspin to reduced-order analysis and achieving change-out simulation by parachute suspension dynamic model. A reentry optimization control problem is developed and the Radau pseudo-spectral method is used to calculate the glide trajectory. Findings: The established dynamic model and trajectory optimization method can effectively simulate the motion process of balloons and UAVs. The system mass reduction for launching UAVs will not cause damage to the balloon structure. The anti-tailspin parachute can reduce the UAV attack angles effectively. The UAV can glide to the designated target position by adjusting the attack angle and sideslip angle. The farthest flight distance after launching from 20 km height is 94 km and the gliding time is 40 min, which demonstrates the potential application advantage of high-altitude launching. Practical implications: The research content and related conclusions of this article achieve a closed-loop analysis of the flight mission chain for the "balloon-borne UAV system," which provides simulation references for relevant balloon launching experiments. Originality/value: This paper establishes a complete set of numerical simulation models and can effectively analyze various postlaunching behaviors. [ABSTRACT FROM AUTHOR]

This article presents the conceptual design, operation principle, dynamic modeling, and simulation results of a discrete incremental hydraulic positioning system (DIHPS) intended for use in high-precision, heavy-load industrial automation solutions. An original solution for precise incremental step positioning using DIHPS is proposed, comprising an n-step linear double-acting hydraulic actuator (HA) with a double rod, cylinder sleeve with outflow gaps, binary valves (BVs) bleed-off into the tank, and fixed throttle valves (TRVs) at the inlets of the actuator chambers. The discrete incremental shift of the HA is determined by controlling the opening and closing of the individual BVs, and the step shift of the HA piston stops at the opening location of the BV. A dynamic model of incremental step shift for DIHPS is developed, considering the behavior and relationships of its individual elements. A dynamic model of HA with and without a hydropneumatic accumulator (HPA) is presented. HPA has been shown to effectively dampen piston vibrations and pressure peaks at the HA stop position. The design assumptions, dynamic models, and discrete incremental positioning of the DIHPS are verified by simulation tests and assessed with quantitative indicators. Innovative DIHPSs have significant practical potential in the discrete incremental positioning of heavy loads. [ABSTRACT FROM AUTHOR]

To explore the impact of wheel-rail excitation on the dynamic performance of axle box bearings, a dynamic model of the high-speed train including axle box bearings is developed. Subsequently, the dynamic response characteristics of the axle box bearing are examined. The investigation focuses on the acceleration characteristics of bearing vibration under excitation of track irregularities and wheel flats. In addition, experiments on both normal and faulty bearings are conducted separately, and the correctness of the model and some conclusions are verified. According to the research, track irregularity is unfavorable for bearing fault detection based on resonance demodulation. Under the same speed conditions, the acceleration peak of bearing is inversely proportional to the length of the wheel flat and directly proportional to its depth. The paper will contribute to a deeper understanding of the dynamic performance of axle box bearings. [ABSTRACT FROM AUTHOR]

For high-speed railways, the smoothness of the railway line significantly affects the operational speed of trains. When the train passes through the turnout on a long-span bridge, the wheel-rail impacts caused by the turnout structure irregularities, and the instability arising from the bridge's flexural deformation lead to a strong coupling effect in the vehicle-turnout-bridge system. This significantly affects both ride comfort and operational safety. For addressing this issue, the present study considered a long-span continuous rigid-frame bridge as an example and established a train-turnout-bridge coupled dynamic model of high-speed railway. Utilizing a selfdeveloped dynamic simulation program, the study analysed the dynamic response characteristics when the train passes through the turnouts on the bridge. It also investigated the influence of different span-to-depth ratios of the bridge on the vehicle dynamic response when the train passes through the main line and branch line of turnouts and then proposed a span-to-depth ratio limit value for a long-span continuous rigid-frame bridge. The research findings suggest that the changes in the span-to-depth ratio have a relatively minor impact on the train's operational performance but significantly affect the dynamic characteristics of the bridge structure. Based on the findings and a comprehensive assessment of safety indicators, it is advisable to establish a span-to-depth ratio limit of 1/4500 for a long-span continuous rigid-frame bridge. [ABSTRACT FROM AUTHOR]

Aliquoting of biological samples refers to the process of dividing a larger biological sample into smaller, representative portions known as aliquots. This procedure is commonly employed in laboratories, especially in fields like molecular biology, genetics, and clinical research. Currently, manual dosing devices are commonplace in laboratories, but they demand a significant amount of time for their manual operation. The automated dosing devices available are integrated into narrowly focused aliquoting systems and lack versatility as manipulator equipment. Addressing this limitation, a novel technical solution is proposed in this paper for a modular dosing device compatible with robotic manipulators. The paper introduces and details a mathematical model, optimizes its parameters, and constructs a detailed 3D model using the NX environment to demonstrate the engineering feasibility of our concept. It further outlines the development of a three-dimensional dynamic simulation model for the dosing device, comparing analytical calculations with simulation results. The construction of a dosing device prototype is discussed, followed by a comprehensive experimental validation. [ABSTRACT FROM AUTHOR]

A musculoskeletal (MSK) model is a valuable tool for assessing complex biomechanical problems, estimating joint torques during motion, optimizing motion in sports, and designing exoskeletons and prostheses. This study proposes an open-source upper body MSK model that supports biomechanical analysis of human motion. The MSK model of the upper body consists of 8 body segments (torso, head, left/right upper arm, left/right forearm, and left/right hand). The model has 20 degrees of freedom (DoFs) and 40 muscle torque generators (MTGs), which are constructed using experimental data. The model is adjustable for different anthropometric measurements and subject body characteristics: sex, age, body mass, height, dominant side, and physical activity. Joint limits are modeled using experimental dynamometer data within the proposed multi-DoF MTG model. The model equations are verified by simulating the joint range of motion (ROM) and torque; all simulation results have a good agreement with previously published research. [ABSTRACT FROM AUTHOR]

Several kinesin-5 motors (kinesin-5s) exhibit bidirectional motility. The mechanism of such motility remains unknown. Bidirectional kinesin-5s share a long N-terminal nonmotor domain (NTnmd), absent in exclusively plus-end-directed kinesins. Here, we combined in vivo, in vitro, and cryo-electron microscopy (cryo-EM) studies to examine the impact of NTnmd mutations on the motor functions of the bidirectional kinesin-5, Cin8. We found that NTnmd deletion mutants exhibited cell viability and spindle localization defects. Using cryo-EM, we examined the structure of a microtubule (MT)-bound motor domain of Cin8, containing part of its NTnmd. Modeling and molecular dynamic simulations based on the cryo-EM map suggested that the NTnmd of Cin8 interacts with the C-terminal tail of ß-tubulin. In vitro experiments on subtilisin-treated MTs confirmed this notion. Last, we showed that NTnmd mutants are defective in plus-end-directed motility in single-molecule and antiparallel MT sliding assays. These findings demonstrate that the NTnmd, common to bidirectional kinesin-5s, is critical for their bidirectional motility and intracellular functions. [ABSTRACT FROM AUTHOR]

Purpose: This study proposes a tensegrity-based traction structure with D-bar dual cable units. It is used to connect the airship and the ground to stabilize the airship. Design/methodology/approach: The mathematical models and dynamic models of the D-bar dual cable (hereafter referred to as DD cable) unit of the tensegrity-based traction structure are established. Based on the minimum mass method, the mass of the DD cable unit in the critical state (cable member is yielding, or bar member is buckling or yielding) is analyzed. Then, the tensile strength of the DD cable unit and single cable unit under the same condition is compared using the control variate method. Finally, based on ANSYS dynamic simulation, the stability of the two structures under the same external force disturbance was tested. Findings: Expressions for the minimum mass of the DD cable unit under different failure conditions are solved. Dynamic simulation results show that the capacity of resisting disturbance of the DD cable unit is much better than that of the single cable unit under the same wind speed. So, we find a structure more suitable for the fixed connection of an airship. Originality/value: This study helps to provide theoretical reference and thinking for the practical application of the traction structure with a D-bar dual cable unit. [ABSTRACT FROM AUTHOR]

Purpose: The dynamic modeling and simulation of a folding-link flexible manipulator based on the Bezier Interpolation Method (BIM) have been taken into consideration for investigation. Method: BIM is utilized to describe the deformation field of flexible links in which the coupling of the axial and transverse deformations are included. Lagrange equation is adopted in conjunction with the homogeneous transformation matrix to derive the dynamic equations of the flexible manipulator, and relevant dynamic constraint equations are also given. Several examples are presented to verify the accuracy and validity of the present dynamic modeling theory for the flexible manipulator. Results and Conclusion: BIM-based dynamic response of flexible manipulators are consistent with those based on Finite Element Method (FEM) and Assumed Mode Method (AMM). As a new discretization method of the deformable body, BIM can effectively describe the deformation field of flexible links, and it is also applicable to the dynamic modeling of multi-link flexible manipulators. The proposed dynamic equations can be improved to perfectly deal with the dynamic problem of flexible manipulators with folding links by adding constraint equations. Through the study of the dynamic characteristics of the right-angle folding-link manipulator under free fall, we can see that the steady state of the right-angle folding-link manipulator needs a long time, this shows that there is a more significant rigid-flexible coupling effect in the right-angle folding-link manipulator system. [ABSTRACT FROM AUTHOR]

In order to address the time-consuming and labor-intensive challenges as well as the suboptimal operational quality encountered in the conventional processes of fruit bagging within expansive orchards, an innovative end-of-bagging actuator is proposed, which can be installed on a fruit-production robot. Due to the excessive power sources required to complete the bagging operation, while also taking into account the quality and cost of the end effector, we have implemented a clutch transmission system to control individual motors, thereby achieving efficient bag-opening and collection actions. Through kinematic analysis of the bagging end effector, the optimal bag opening size is determined to be 40.3372 mm, with a deviation of 0.1428 mm from the design target and an error rate of 0.35%. This ensures the desired bag size for bagging juvenile fruits. Moreover, a dynamic simulation model comprising rigid drive components and a flexible clutch was developed. The simulation results demonstrate the system's stable performance. However, it is evident that the gear speed falls below that of the flexible clutch, resulting in insufficient bag opening and bag gathering compared to the intended design target. The observed phenomenon is a result of the characteristics exhibited by the flexible clutch. Specifically, the demands for bagging and stretching can be accommodated by modifying the stiffness and geometric configuration of the flexible clutch, alongside the level of operational force. To conclude, the suggested end effector can successfully simulate the implementation of the manual bagging process. By taking into account the quality and cost of the end effector, a clutch drive system was utilized to regulate a single motor, resulting in efficient bag-opening and collection actions. This approach offers a more integrated and efficient solution compared to manual bagging and semi-automatic mechanically assisted bagging methods. [ABSTRACT FROM AUTHOR]

E-scooter vibrations are a problem recently studied. Theoretical models based on dynamic simulations and also real measurements have confirmed the high impact of e-scooter vibrations on driver comfort and health. Some authors recommend improving e-scooter damping systems, including tyres. However, it has not been suggested nor has any research been published studying how to improve e-scooter frame design for reducing driver vibrations and improving comfort. In this paper, we have modelled a real e-scooter to have a reference. Then, we have developed a multibody dynamic model for running dynamic simulations studying the influence of mass geometry parameters of the e-scooter frame (mass, centre of gravity and inertia moment). Acceleration results have been analysed based on the UNE-2631 standard for obtaining comfort values. Based on results, a qualitative e-scooter frame design guide for mitigating vibrations and increasing the comfort of e-scooter driver has been developed. Some application cases have been running on the multibody dynamic simulation model, finding improvements of comfort levels higher than 9% in comparison with the e-scooter reference model. The dynamic model has been qualitatively validated from real measurements. In addition, a basic sensor proposal and comfort colour scale is proposed for giving feedback to e-scooter drivers. [ABSTRACT FROM AUTHOR]

Due to intricate operating conditions, including structural clearances and assembly deviations, the acquisition of test data for the landing gear retraction mechanism is limited, posing challenges for reliability analysis. To solve the problem, a Bayesian-based reliability analysis method fusing prior and test data is proposed, focusing on the mechanism kinematic accuracy under small-sample conditions. Firstly, a dynamic simulation model is established to collect prior data, and retraction tests are conducted to obtain test data. Then, based on Bayesian theory, the motion accuracy parameter estimation model integrating prior and test samples is established. To obtain accurate hyper parameters, the prior samples are expanded using the neural network. Finally, taking the retraction mechanism as the research object, the kinematic accuracy reliability is quantified, and the impact of uncertainty factors is analysed in depth. The results show that the proposed method is superior to the classical interval estimation method in stability and effectively mitigates the impact of uncertainty factors. [ABSTRACT FROM AUTHOR]

This study implements a comprehensive dynamic simulation using a moving-boundary method to characterize an organic Rankine cycle under assumption-free operating conditions. The novelty of the model lies in its unique methodology for determining the state vector variables and initial conditions of the system, particularly in integrating sub-models, notably the model of liquid receiver. Consequently, the implemented dynamic model accurately forecasts the system's performance, focusing solely on the boundary conditions. A comprehensive dynamic model is constructed, encompassing a wide range of scenarios and facilitating the interchangeability of models as required. One notable advantage of the model is its systematic approach, which begins each simulation by determining the system's initial conditions before conducting the dynamic model in parametric and dynamic studies. The capability and accuracy of model is confirmed through comparison with experimental data under various steady-state and dynamic conditions, while adhering to the main rules of mass and energy conservation. The prediction accuracy of the model is evaluated by mean absolute percent error. According to the results, the maximum deviations of simulation results mostly are less than 11 %. • Using moving-boundary method to simulate an ORC under assumption-free conditions. • Using unique method for determining state vector variables and initial conditions. • Dynamic model precisely forecasts system performance, focusing on boundary conditions. • The maximum deviations between the simulation and experimental results are 11 %. • The simulation shows ORC's dynamic behavior when input conditions vary. [ABSTRACT FROM AUTHOR]

Heat–power decoupling is a key issue to be addressed for the combined heat and power (CHP) unit to enhance its operational flexibility, and utilizing heat storage in district heating systems represents a viable approach. The widespread adoption of heat pumps to boost heating network also increases the complexity of managing heat storage, and the quantitative impact of heat storage has significant implications during operation. To this end, dynamic models of heating networks and heat pumps were developed. A metric, the maximum maintenance time, was established to quantitatively assess heat storage utilization. Dynamic simulations and performance analyses were conducted on a 330 MW CHP unit. The results indicate that by employing heat storage, the feasible maximum and minimum output power of the heating system can be increased by 20 MW and decreased by 45.5 MW, respectively. With the integration of a heat pump, these values can further increase by 9 MW and decrease by 158 MW, respectively, significantly enhancing the operational flexibility of CHP unit. • Dynamic models of CHP unit, heating networks and heat pump were developed. • A new index to evaluate the heat storage capacity that can be used is proposed. • Dynamic simulation and performance analysis were conducted with a 330 MW CHP unit. • The integration of heat pump can increase heat storage capacity for peak shaving. • The feasible minimum output power of the CHP unit can be decreased by 158 MW. [ABSTRACT FROM AUTHOR]

In this study, lignocellulose-derived aerogel (LA) with compression-rebound was synthesized from liquefied wood through sol-gel polymerization, aging and freeze-drying process. The results presented a gradual increase in the compressive strength, flexural strength, and maximum decomposition temperature of the LA sample with prolonged aging time from 3 to 10 h, demonstrating excellent elasticity and thermal stability. After more than 10 h, the bending strength began to decrease, indicating that the material's rigidity was greater than its elastic toughness at this time. A nonlinear viscoelastic constitutive model based on the Ogden function and parallel rheological framework showed very high correlation with experimental measurement results, and also demonstrated admirable mechanical properties. These predictions can provide an effective approach for the application of LA in buffer packaging. [Display omitted] • Lignocellulose-derived aerogels for buffer packaging was successfully obtained. • Appropriate aging time improved thermal stability and mechanical properties of LA. • High bending strength of 2.64 MPa at 50 % compression strain can be obtained. • LA-E4 achieved excellent compression rebound rate of 96.15 %. • A viscoelastic constitutive model for predicting mechanical behavior was established. [ABSTRACT FROM AUTHOR]

The increasing amount of Distributed Energy Resources (DERs) in Distribution Networks (DNs) has awakened the interest of system operators to represent how DERs will react to large disturbances. These units will respond according to the ride-through capability curves, the tripping logic settings, the local voltage magnitude, and frequency measurements. In this paper, we show the limitations of the well-known DER_A model and propose changes to represent better the ride-through capabilities and the tripping of a population of DER units. We also show the need for more than one aggregation in the same bus to represent the response of the old and modern DER technologies. To validate the new model, we run dynamic simulations of a Transmission Network (TN) and DNs with hundreds of DER units modeled in detail. The simulation results show that the proposed changes improve the representation of a population of DERs during low-voltage and low-frequency events. • Review of discrepancies between DER_A ride-through/trip logic and IEEE Std. 1547-2018. • New aggregate model for distributed energy resources with ride-through capabilities. • Validation of the new ride-through logic by comparing against disaggregated models. [ABSTRACT FROM AUTHOR]

• The service life estimation of linear guideways can be done with damage accumulation. • A model-based condition monitoring of linear guideways is mandatory. • A vibration model of the linear guideway must consider all relevant elasticities. • A vibration model can be used to estimate the pitting size. • The pitting size progression can be used to estimate a remaining service life. The paper describes two novel calculation methods that can predict the service life of linear guideways more accurately than the conventional method. The first method is based on a linear damage accumulation in each rolling contact, which can take into account changing load cycles for a statistically based long-term remaining service life estimation. Since this statistically based estimation still has some inaccuracies, a second method is proposed that uses a dynamic simulation model of the linear guideway to perform a model-based condition monitoring. With this method, a more accurate damage-based prediction of the remaining useful service life can be made in the short term. The dynamic model takes into account both the elasticity of the Hertzian rolling contact and the elasticities of the carriage and rail depending on the dynamic rolling element circulation. The model also includes a simplified pitting model which allows the actual pitting size to be calculated by comparing the simulated vibration behaviour with the measured vibration behaviour. The calculated pitting propagation velocity is used to estimate the remaining useful service life. [Display omitted] [ABSTRACT FROM AUTHOR]

The thermal inertia results in net heat absorption in natural circulation lead-cooled reactors during power variation processes, increasing the risk of core meltdown. In this study, a dynamic simulation model of a natural circulation lead-cooled fast reactor coupled with a supercritical carbon dioxide Brayton Cycle power generation system has been developed based on Vpower. The influence of thermal inertia on system operating temperature under different power variation rates was discussed. The results indicate that during power reduction, different decline rates only affect the temperature variation range of the system without impacting the final stable state. However, during power increase, different ramp rates not only affect the temperature variation range but also lead to varying degrees of system temperature rise. To address this issue, an optimized turbine throttling scheme is proposed. Compared to the original plan, the new plan successfully stabilizes the temperature at the rated value after increasing the system power. This study provides insights for the operation control strategy of similar reactor types. [ABSTRACT FROM AUTHOR]

This work investigates the heat transfer design and performance of three general types of ammonia reactors for Power-to-Ammonia (P2A). Specifically, the reactors are an adiabatic quench cooled reactor (AQCR), an adiabatic indirect cooled reactor (AICR), and an internal direct cooled reactor (IDCR). We present rigorous steady-state and dynamic models for the three reactor types. Steady-state optimisation at nominal load shows that the AICR and IDCR achieve the highest reactant conversion at 30.0% and 29.4% respectively, whereas the AQCR reaction conversion is significantly lower at 26.9%. Through open-loop simulations around the optimal operating point, we illustrate the unstable oscillatory dynamics of the AQCR. In contrast, the AICR and IDCR showcase stable and fast decaying oscillations. Nonetheless, our stability analysis reveals that the optimal operating points for all reactors are situated precariously close to the reactor extinction threshold. As a result, even minor disturbances pose a substantial risk of extinguishing the reactors at optimal operating conditions. We optimise the reactors across an operating window from 30% to 130% of its nominal load, reflecting varying load in a P2A plant. Over this operational range, the AICR and IDCR yield similar reactant conversions and demonstrate adaptability to varying loads by achieving significantly higher conversions at lower loads. In contrast, the AQCR shows a less pronounced increase in reactant conversion at reduced loads. Considering the location of the optimal operating points close to reactor extinction, we evaluate operating the reactors at a 15 K higher feed temperature than optimal value (stability margin). Our analysis demonstrates that a 15 K safety margin only slightly reduces ammonia conversion across the operating window, while ensuring stable operation even in the event of a 15% decrease in the catalyst activity. • Dynamic and steady models for three types of ammonia reactors (AQCR, AICR, IDCR). • Heat exchange design in ammonia reactors for Power-to-Ammonia operation. • Optimisation and comparison of reactor conversions at nominal load. • Step responses of the reactors to disturbances in feed temperature. • Optimal and stable operation from 30% to 130% of nominal load. [ABSTRACT FROM AUTHOR]

• The optical fiber coil with spool (OFCS) is a crucial tool for precise physics measurements. • To improve the seismic resistance of OFCSs in space applications, the vibration modes are thoroughly investigated through dynamic analysis, simulations, and experiments. • We establish a dynamic model of the OFCS based on the vibration transmission mechanism to characterize its vibration modes. • The vibration eigenfrequency and shapes are calculated under various conditions. • The experimental results validate the feasibility of the dynamic model and simulation, meanwhile, the discrepancies between the simulations and experiments are analyzed. • This study is the first of its kind to develop a comprehensive dynamic model for an OFCS, with simulations and experiments confirming its effectiveness. The optical fiber coil with spool (OFCS) is a crucial tool for precise physics measurements. To improve the seismic resistance of OFCSs in space applications, the vibration modes are thoroughly investigated through dynamic analysis, simulations, and experiments. We establish a dynamic model of the OFCS based on the vibration transmission mechanism to characterize its vibration modes. The vibration eigenfrequency and shapes are calculated and simulated under various conditions. The experimental results validate the feasibility of the dynamic model and simulation, meanwhile, the discrepancies between the simulations and experiments are analyzed. This study is the first of its kind to develop a comprehensive dynamic model for an OFCS, with simulations and experiments confirming its effectiveness. [ABSTRACT FROM AUTHOR]

• A plant-wide model is presented for continuous biomanufacturing benchmarking. • The model includes a tailored control strategy for dynamic simulation performance. • Realistic sensors and actuators consider measurement's noise and lag time. • Case study framework and examples are provided for user guidance. The pharmaceutical industry's shift towards biological therapeutics has led to a transition from conventional batch production to continuous manufacturing. This change highlights the crucial need for effective process monitoring and control strategies to ensure consistent product quality and stability. Open-source benchmark simulation models have become essential tools for refining these processes, offering a platform for testing research hypotheses. This study uses the production of Lovastatin as a case study for continuous biopharmaceutical production. A comprehensive dynamic model covering upstream and downstream components provides an integrated perspective of the production process. The study introduces a basic control system emphasizing realistic sensor and actuator integration to enhance simulation accuracy. It assesses the benchmark through open-loop and closed-loop simulations, offering an in-depth analysis of the KTB1 model's dynamic response and functionality. KTB1 represents a model-driven decision support tool that enables the evaluation of monitoring strategies, process design, process optimization, and control for biomanufacturing. [ABSTRACT FROM AUTHOR]

This study proposes a novel, eco-friendly design for a deep-sea floating mining vehicle multi-body system (DFMVMS), incorporating a floating mining vehicle (FMV) as its central mining apparatus. The comprehensive system architecture encompasses a surface mother ship, a main pipe cable, an ore transit station, an umbilical pipe cable (UPC), and the FMV, engineered for deep-sea extraction activities while preserving benthic ecosystems. To investigate the interactions among the multi-body system's components and ascertain the collective motion dynamics during operational states, initial steps involved developing mathematical models for each individual component. Subsequently, a holistic model for the entire DFMVMS was formulated by integrating these component models via coupling boundary conditions, with the model's accuracy subsequently affirmed. Analytical scenarios, including three foundational motion states of the FMV, were structured to explore the influence of FMV dynamics on the DFMVMS's overall behaviour. Moreover, specific operational scenarios were tailored to reflect two principal functions of the DFMVMS—production and transfer. The simulation results significant interplay among the movements of the system's components, highlighting UPC tension as a critical consideration in devising transfer routes. • Introduced an eco-friendly deep-sea mining system with a floating vehicle as the main equipment. • Developed a dynamic model for this complex multi-body system, including a transit station. • Validated the model through simulations of three fundamental floating vehicle operations. • Designed and simulated two real-world operational scenarios, providing practical insights. [ABSTRACT FROM AUTHOR]

Dynamic simulation is a powerful tool for accurately evaluating the thermal demands of buildings and assessing the impact of energy refurbishment actions on their final consumption. Conversely, semi-stationary models are widely adopted in commercial applications for its simplified approach, which reduce calculation times, resulting in standardized results showing a certain deviation with respect to the real energy This paper presents the energy and economic comparison between the dynamic simulation and semi-stationary approaches for the calculation of primary energy demand of residential buildings. The semi-stationary method, used by the legislation to calculate the buildings energy label, is based on an energy performance parameter, not representative of the real energy demand. Conversely, an approach based on dynamic simulation provides a more reliable estimation of the primary energy demand. The main novelty of this paper is to numerically prove that the energy and economic savings calculated by means of software based on the current legislation may be overestimated. In this work, the dynamic simulation of the building-plant system is performed by TRaNsient SYstem Simulation (TRNSYS) program. Each building apartment is divided in thermal zones, where the internal heat gains are defined in detail. The semi-stationary simulation of the building-plant system is performed according to the Italian standard UNI TS 11300. The models allow one to evaluate the yearly primary energy demand, along with the energy bill and CO 2 emissions. A specific case study is developed for a residential building located in Naples (Italy). The models are used to calculate the building energy demand for several scenarios, considering different thermal transmittances of the building elements. The results show that the semi-stationary method overestimates of primary energy saving, equal to 64.7 %, with respect to the one calculated with the dynamic approach, equal to 43.2 %. • Semi-stationary and dynamic simulations were compared for residential buildings. • Critical evaluation of energy and economic savings due to the building refurbishment. • Primary energy savings of 65 % and 43 % by semi-stationary and dynamic simulation. • Dynamic simulation is needed within the legal frame of energy efficient buildings. [ABSTRACT FROM AUTHOR]

In this study, two processes of predictive model combining dynamic simulation and regression model were presented. First, (1) the demand forecasting process defined in this study is a method of predicting energy consumption based on the simulated energy consumption of a target building, and (2) the energy saving process is a method of setting an energy reduction target based on the predicted energy consumption and providing energy saving measures to achieve the target. Specifically, there are two functions based on the regression models which are predicting actual energy consumption by inputting the energy consumption simulation data, and inversely inputting the actual energy consumption and deriving the corresponding simulation conditions. As a result of predicting building energy consumption through the demand forecasting process, the performance in the heating season showed CV-RMSE was 14.622%, and in the cooling season CV-RMSE was 5.877%. In addition, in the case study using the energy saving process, it was possible to derive the heating and cooling set temperature for 5% energy saving as an energy saving method by using weather forecast data. • Demand forecasting and energy saving of buildings. • Regression model-based process between simulation-based predictions and actual energy consumption. • Two processes combining TRNSYS and DNN model to ensure building energy management efficiency. [ABSTRACT FROM AUTHOR]

• We conduct 61 simulations to select a preferred model using the grid search method. • We constrain dynamic simulations with geodetic, seismic, and geological observations. • The 2022 Menyuan earthquake nucleated vigorously and could grow into a large event. • The fault bend and stepover act as stress barriers and terminate the rupture early. The 2022 Mw 6.6 Menyuan earthquake, which caused unexpectedly large surface offsets (about 2.6–3.5 m) relative to the moment magnitude of this event, is one of the best-recorded strike-slip events in the northeastern Tibetan plateau. Although previous studies have revealed many kinematic features of this event, the mechanism and rupture dynamic characteristics underlying unexpectedly large surface dislocations need to be clarified. In this study, based on the grid search method, we conducted 61 dynamic rupture simulations considering terrain relief to screen out a preferred dynamic model that fits the geodetic, seismic, and geological observations well. The results show that the average stress drop of the nucleation part is relatively high (11 MPa), which could provide high initial rupture energy and give this event a chance to develop into a large earthquake. However, the rupture propagating eastward is slowed and terminated by two consecutive fault bends of about 10° each, and the westward propagating one might concentrate at a shallow depth (< 3 km) on the south secondary fault after it jumps over the stepover. These results imply that the complex fault geometry (the fault bend and stepover) might terminate the rupture early so that the observed magnitude of this event (Mw 6.6) is smaller than the estimated magnitude (Mw 7.1–7.2) based on the surface offsets. Our study again shows that, due to advances in computational power and observations (coverage and quality), physics-based dynamic rupture simulations have entered an era where it is possible to fit the observed data well, which is vital for further understanding the mechanisms of earthquakes. [ABSTRACT FROM AUTHOR]

• Dynamic simulation model is able to predict real column behavior during start-up. • New start-up strategy for the pilot multiple dividing wall column is proposed. • Start-up time of the column strongly depends on the selected strategy. • Start-up of the pilot multiple dividing wall column is possible within few hours. Multiple dividing wall columns are a promising extension of the concept of dividing wall columns offering energy savings of up to 55 % compared to conventional distillation sequences for four products. This paper presents the first systematic study on the start-up of a multiple dividing wall column. The study aims to develop a start-up strategy for the first pilot multiple dividing wall column worldwide commissioned at Ulm University. The start-up process is investigated using a dynamic simulation model that facilitates the investigation of different start-up strategies and the influence of different factors on the start-up process. Based on these dynamic simulations a viable start-up procedure for the column is found. Through improvements to the procedure a significantly shortened start-up process is achieved. The dynamic response of the column shows that the cold and dry plant is able to reach the desired operating point within few hours. Simulation results are confirmed with experimental data from the pilot column. [Display omitted] [ABSTRACT FROM AUTHOR]

The deepwater S-lay pipeline maintains high tension, bending moment, and stress in the overbend section, exhibiting substantially dynamic responses due to pipe-stinger roller interactions. This paper presents a refined S-lay pipeline model capable of accurately describing the forces and deformations on the pipeline section. In this model, the pipeline is discretized into beam particles and beam elements using the vector form intrinsic finite element (VFIFE) method. Meanwhile, the equivalent beam particle technique is developed to account for both the local forces and deformations of the pipeline as well as its overall static and dynamic responses. Through program coding, a dynamic time-domain simulation was accomplished for a 12-inch pipeline being laid to a water depth of 1000 m to provide a detailed illustration of the S-lay modeling process. Furthermore, dynamic behaviours of the pipeline in the overbend were systematically investigated under various groups of the pipe diameter and the stinger roller spacing. The results indicate that the stress and deformation on the upper section of the pipeline are more significant than those on the lower section. The equivalent beam particle method extends the capabilities of the VFIFE for the detailed analyses of local dynamic behaviours of deepwater S-lay pipelines. • A refined VFIFE model of deepwater S-lay pipeline is proposed to investigate the overall and local internal forces and deformations. • The equivalent beam particle technique with the extension of the VFIFE method is developed to calculate pipeline stress and strain in the overbend section. • The accuracy and effectiveness of the refined VFIFE model are fully verified. • Significant differences of the pipeline local stress and strain between the upper and lower sections are observed. • The effects of pipe diameter and stinger roller spacing on the pipeline section behaviours are identified. [ABSTRACT FROM AUTHOR]

Power electronics converters have been widely deployed in modern power systems in different voltage levels. The complex operation characteristics of power converters, which combine different control modes and various current saturation states, are also significantly changing the power systems' behavior in fault conditions. The objective of this paper is to develop a steady-state short-circuit calculation solver for power systems with power electronics without the need of detailed dynamic models. In particular, the steady-state operation equations related to the converter control are included in the system formulation. An extended Newton–Raphson (NR) solver is proposed to compute the short-circuit equilibrium point that considers converters' operation limits. Also, an iterative algorithm is presented in order to efficiently identify the current saturation states of power converters under a specific short-circuit fault scenario. Case studies have been presented with several power systems with voltage source converters (VSCs). Dynamic simulations are included to validate the accuracy of the proposed methodology. • This paper presents an extended Newton–Raphson solver to cope with the new formulation considering power converters' operation. • An iterative algorithm that identifies the current saturation state of a converter in a specific fault scenario. • The proposed methodology has been implemented in several benchmark systems with VSCs. simulation results. [ABSTRACT FROM AUTHOR]

Barocaloric refrigeration technology is a promising candidate for next-generation refrigeration technologies attributed to its eco-friendliness, high efficiency, and mechanical stability. To date, research in this field has predominantly focused on the exploration of solid-state refrigerants. However, the development of barocaloric systems is currently hindered by a lack of both prototype models and a comprehensive theoretical foundation. Addressing this gap, this study innovatively introduces the first model of a barocaloric refrigeration system, characterized by efficient hydrostatic pressure transitions and rapid heat and cold extraction. The employed refrigerant, neopentyl glycol, is notable for its low cost and significant barocaloric effect. Through the development of a one-dimensional dynamic numerical model for the system, this study investigates the system's temperature variability and operational efficiency under varying design parameters and operating conditions. Simulations suggest that the system could achieve a maximum COP of 13.1 and a refrigeration capacity of 106.4 W at a temperature span of 10 K. Additionally, the system is capable of reaching a maximum temperature span of 18 K under no-load conditions. This research not only underscores the theoretical viability of barocaloric refrigeration, but also provide crucial theoretical support and guidance for the design and construction of the first-generation barocaloric refrigeration prototype. • A first-generation barocaloric refrigeration prototype was innovatively proposed. • A one-dimensional dynamic model for barocaloric refrigeration is established. • The system achieves a notable COP of 13.1 and refrigeration capacity of 106.4 W. • The system can achieve an impressive maximum temperature span of 18 K. [ABSTRACT FROM AUTHOR]

This paper analyzes the dynamic character of a planar multi-degree-of-freedom industrial machine using an industrial robot as a reference model. A nonlinear dynamics model of a multi-body structure including the end effector, base and the manipulator is established using the Lagrange's principle. The validity was verified by ADAMS simulation with the established dynamic model. Focusing on the low-frequency region, the influence of the robot assembly parameters on the vertical vibration response of the body is discussed. Based on the data summary, some optimization recommendations are made. The results of this paper may contribute to the design of vibration isolation for such robotic arm structures. • Considered the nonlinear multi-body dynamics of an industrial machine. • Established a seven-degree-of-freedom nonlinear dynamics model and verified by ADAMS. • Multiple super-harmonic resonance peaks and complex soft nonlinear phenomena were observed. [ABSTRACT FROM AUTHOR]

Pumped thermal energy storage (PTES) technology offers numerous advantages as a novel form of physical energy storage. However, there needs to be a more dynamic analysis of PTES systems. This paper proposes a dynamic simulation model of the PTES system using a multi-physics domain modeling method to investigate the dynamic response of key system parameters during the system's start-up and variable operating conditions. Additionally, the impact of equipment parameters on system characteristics was analyzed. Furthermore, a comparative analysis was conducted to assess the variation in system characteristics when considering the different working medium properties. The results show that the system cavity volume should be selected as 5 m3, and the initial pressure of the system during the charge/discharge period should be selected as 2.1 MPa and 3.8 MPa, respectively. The system runs to the design operating conditions during the start-up process in about 1400 s. In the process of variable operation conditions, the power load in the charge/discharge period can be increased or reduced from the rated value by gas filling or venting, and the system characteristics change accordingly. The simulation model and research findings will offer theoretical insights for optimizing the design of the PTES system. • A dynamic simulation physical model of the PTES system was proposed. • The dynamic changes in system characteristics were analyzed. • The TES tank's thermal inertia and heat management of the PTES system were analyzed. • The effects of main equipment parameters on system characteristics were analyzed. • System characteristics were compared when using different gas properties. [ABSTRACT FROM AUTHOR]

• A contact multi-body dynamics model of an RV reducer is presented. • Vibration properties of RV reducer under excitation of faulty NBRs are studied. • The accuracy of the dynamic model has been confirmed by experimental tests. • Defect excitation has a unique periodic effect on the RV reducer's vibration. • The condition monitoring of RV reducer is supported by simulation and test data. The rotate vector (RV) reducer's needle roller bearings (NRBs) are vulnerable to wear and flaws such as fatigue spalling of the raceway material. Studying the vibration mechanism and the excitation laws of NRB failures is essential to enhancing the RV reducer's performance and comprehending its operating state. This paper presents a dynamic model of the RV reducer based on the theory of contact multibody dynamics. It integrates internal and external raceway defects and takes into account the synchronous contact interaction between NRB groups and the crankshaft and cycloidal gears, as well as the time-varying mesh stiffness in the planetary gear transmission and cycloidal pin transmission. The study demonstrates that the rolling of bearings and the meshing of internal transmission components are the primary causes of vibration in a healthy RV reducer through experimental verification and dynamic simulation analysis of the system with and without NRB failures. Both the crankshaft rotation frequency and the cycloidal gear rotation frequency affect the vibration excitation source's characteristic frequency. The vibration amplitude of the RV reducer is influenced by bearing flaws on a periodic basis. The impact of internal raceway defects is greater than that of external raceway faults, resulting in a notable rise in vibration amplitude. [ABSTRACT FROM AUTHOR]