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Aiming at the requirements of strong mobility and high flexibility of rescue and relief mobile pump trucks, this paper designs a new type of mobile pump truck frame based on existing mobile vehicle frame models. The materials used for the frame are 40Cr and Q235, and the finite element method is utilized to carry out static mechanical analysis and dynamic characteristic analysis. Simultaneously utilizing topology optimization and multi-objective genetic algorithm to optimize the design of the frame structure. The results show that the optimized pump truck frame can meet the strength design requirements of four typical working conditions: full load bending, full load torsion, emergency turning and emergency braking, while avoiding resonance phenomena caused by road surface and diesel engine vibration. Compared with the original frame model, the weight of the optimized frame is reduced by 87.88 kg, with a weight reduction rate of 10.89%, realizing the lightweight design requirements. [ABSTRACT FROM AUTHOR]

In order to study the influence of slip structure on the mechanical behavior and residual strength of casing, parameters such as support force and friction force between slips and casing were derived based on the interaction relationship between slips and casing. Tensile tests were conducted on casing materials in this paper, and the working process of anchoring casing with single and double slips was simulated. The influence of indentation depth on the residual strength of casing was analyzed. The results show that the deformation of the casing is relatively severe when the single slip sealing force reaches 120 kN. According to the law of residual strength curve, there is a turning point where the stress concentration factor tends to be gentle, and the corresponding indentation depth value at this point increases with the increase in casing diameter. Single slips were unable to effectively bite into P110 and P125 casings, and the bite did not achieve the effect of setting the casing. However, when double slips were used to anchor the casing, the inner wall of the casing had deeper indentation, and the double slips could firmly seat the casing. These results indicate that replacing single slips with double slips can effectively achieve the setting effect. [ABSTRACT FROM AUTHOR]

During the drilling process, the pressure measurement device of logging while drilling is affected by the severe vibration and impact load of the drill string, which is likely to cause fatigue damage to the weak parts. To study the anti-vibration performance of the small logging while drilling instrument, a finite element model of the drill string was established in this paper combined with finite element technology. Moreover, this paper analyzes the vibration frequency of the drill string and gives the method of using different drilling tools and drilling speeds at different depths to reduce the damage to the measuring device caused by the resonance of the drill string. Then, this paper analyzes the impact load to obtain the acceleration and displacement changes of the measuring device. In addition, this paper analyzes the anti-vibration performance of the instrument in the assembly of the outer steel pipe, including modal analysis, harmonic response analysis and random vibration analysis, and finds the weak link of the structure. Through experimental research, it can be known that the finite element method proposed in this paper has a certain effect in the analysis of the anti-vibration performance of the small instrument of Logging While Drilling. [ABSTRACT FROM AUTHOR]

Three-phase linear synchronous actuators play a pivotal role in precision motion control applications such as lithography machines and laser material processing stages. Achieving superior tracking performance is paramount in the design of motion control systems, prompting the utilization of advanced control algorithms. In this study, a novel approach is presented to enhance the tracking capability of a three-phase permanent magnet actuator by introducing a predictive field-oriented control system. The primary contribution of this paper lies in the comprehensive design and implementation of the predictive field-oriented control system. Initially, actuator modeling is conducted in the rotating reference frame (d–q frame) and finite element analysis is performed to determine key electrical quantities, including magnetic flux densities and inductances. To address the challenges posed by time-varying sinusoidal electrical signals, a field-oriented control methodology is proposed. Notably, the novelty of this work is underscored by a distinct emphasis on the predictive control strategy employed in the system. The predictive controller is implemented on a 32-bit ARM Cortex microcontroller, showcasing the practical viability of the proposed approach. Experimental results substantiate the effectiveness of the proposed method in achieving precise trajectory tracking. This paper contributes to the field by providing a rigorous analysis of a three-phase permanent magnet actuator and introducing a predictive field-oriented control system. The methodology outlined here enhances tracking capabilities and signifies a substantial advancement in the broader landscape of precision motion control systems. Thus, this work adds valuable insights to the existing body of knowledge in the domain, while offering a notable contribution to the field. [ABSTRACT FROM AUTHOR]

Accelerated bridge construction (ABC) is prevalent all over the world attributable to its technical advantages including the higher construction efficiency, less traffic disruption, and higher construction quality. Grouting sleeves (GS) and grouting corrugated pipes (GCP) are the traditional connection methods of ABC in high seismic regions, with the disadvantages of uncompacted grouting and high requirement of construction accuracy. To this end, this paper developed a new type of prefabricated concrete bridge pier connected with ultra-high performance concrete (PCBP–UHPC) jacketing to solve the problems. To validate the seismic performance of the proposed innovative bridge pier, quasi-static tests on three full-scale specimens PCBP–UHPC, PCBP–GS, and PCBP–GCP were carried out. The results indicated that the failure mode of specimen PCBP–UHPC was similar to that of specimens PCBP–GS and PCBP–GCP with the characteristics of longitudinal steel yielding and concrete crushing at the base of the hollow pier. The obvious plastic hinge outward shifting could be observed during the loading for specimen PCBP–UHPC. The positive ultimate load of specimen PCBP–UHPC was 636.33 kN, which was 14.8% and 13.3% higher than those of specimens PCBP–GS and PCBP–GCP, respectively. In addition, a refined finite element model (FEM) was established by ABAQUS to provide an in-depth understanding on the failure mechanism of the proposed PCBP–UHPC. The parametric analyses were conducted to reveal the influence of the socket depth and axial compression ratio on seismic performance of the proposed PCBP–UHPC. The results indicated that the socket depth had little effect on seismic performance of the prefabricated pier, while the ultimate load bearing capacity of specimen PCBP–UHPC increased to some extent as the increase of the axial compression ratio. The present research work provides an innovative prefabricated bridge pier and a comprehensive experimental–numerical understanding on its seismic performance, which is beneficial for its engineering application. [ABSTRACT FROM AUTHOR]

This paper highlights the development and validation of two innovative modular cantilever (MC) designs for railway overhead applications. Existing MCs are heavy, complex, and prone to failures. Addressing these shortcomings, the proposed designs leverage topology optimization and TRIZ principles to achieve significant improvements: weight reduction: Up to 28% lighter than existing MCs due to optimized material distribution. Enhanced robustness: Improved structural efficiency and strength, reducing failure risk. Simplified assembly and maintenance: fewer components and modular design facilitate easier handling and installation. Environmental resistance: increased durability against fatigue cracking, corrosion, and wear and tear. Numerical calculations and finite element analysis validate the performance of the new designs, confirming their ability to withstand dynamic loading conditions equivalent to traditional MCs. These lightweight, robust, and adaptable solutions offer tremendous potential for reducing costs, improving safety, and optimizing performance in railway overhead applications. [ABSTRACT FROM AUTHOR]

Aluminum honeycomb sandwich structure with panels made of carbon fiber reinforced polymer (CFRP) are widely used in aerospace and other fields. Simulation of the eddy current (EC) testing of the sandwich structure using the finite element (FE) method is challenging as the traditional FE method has difficulties in mesh division and the solution of the algebraic equations. This paper proposes to use the domain decomposition FE method to solve such problems. The top CFRP panel, the aluminum honeycomb core, and the bottom CFRP panel of the sandwich structure and the ferrite core of the coil are placed in different subdomains and the subdomains are meshed independently. This method simplifies the mesh generation and does not require regenerating the meshes when simulating the scanning testing with the ferrite-core coil. In this way, the efficiency of simulation is greatly improved. The EC distributions in the sandwich structure are computed and the influence of defect on EC distribution is analyzed. The C scans of the sandwich structures are simulated. The images of the EC responses to the defects, such as wall fracture, node disconnection, and core wrinkle, are obtained. The simulation results are validated by experiments. [ABSTRACT FROM AUTHOR]

An SHS-CFSHS X-joint is fabricated by welding two square hollow section (SHS) braces to a concrete-filled square hollow section (CFSHS) chord. In this paper, the stress concentration factors (SCFs) of SHS-CFSHS X-joints are investigated through experimental tests and finite element analysis (FEA), with the hot spot stress method serving as the analytical approach. Eight specimens are designed and manufactured, with FE models built in software ANSYS. These FE models are validated against the test results. The specimens are tested under brace axial tension to determine the SCFs of the X-joints. It shows that the concrete filled in the chord effectively reduces the SCFs of the X-joints. To further explore various load conditions and the influence of the parameters, FEA is carried out and a total of 64 FE models are built. Based on the FEA results, multiple regression analysis is used to obtain the SCF formulae of SHS-CFSHS X-joints under axial tension load and in-plane bending load in the brace, respectively. Comparison and analysis of the SCF results obtained from experimental tests, the proposed formulae, and FE simulations reveal that the formulae presented in this study are both conservative and suitable for predicting SCFs. [ABSTRACT FROM AUTHOR]

The bumper is an automotive part act as a protective shield in the vehicle. It bears and absorbs the load when the vehicle incurs a collision. If the bumper has got more weight it leads to more fuel consumption and decreases the fuel efficiency of the vehicle. This problem can be overcome by reducing the weight of the bumper without compromising its performance. The main objective in bumper design and fabrication is that it should possess less weight and at the same time, it should withstand the higher load during a collision. In this paper, the properties and performance of the developed bumper composite are compared with the existing bumper. The bumper performance is optimized using a finite element analysis with ANSYS R15.0. From the cost analysis, it has been observed that the weight and cost of the Basalt composite bumper is 49% and 56% lesser than the steel bumper. The Impact strength and Factor of Safety values of the Basalt fabric composite bumper is 47.6% and 32.5% higher than the steel bumper. The total deformation of the Steel bumper is 15.7 mm, and the Basalt composite bumper is 32 mm, which shows 51% higher deformation than steel. [ABSTRACT FROM AUTHOR]

Estimating losses accurately for magnetic materials in power conversion circuits is a challenging task. Solving the partial differential equations in a complex geometry of inductive components such as filter-integrated transformers is an additional prominent challenge. While there are some commercially available finite element simulation tools that provide loss calculations in time-domain for multi-dimensional geometries of magnetic materials, the principle of analysis is not fully disclosed and less flexible for engineers to use. In this paper, we introduce a comprehensive method for systematically and flexibly applying time-domain dynamic loss equations to geometric finite element methods in multi-dimensions. The developed post-process framework for magnetic core loss calculations is coded in an open-source programming language, Python, and verified by comparison with analytical solutions for a filter integrated isolation transformer under a variety of operating conditions. Parallel processing is used to deal with the large datasets associated with element-by-element numerical calculations in the time domain. A high level of accuracy is achieved and verified. [ABSTRACT FROM AUTHOR]

Background: The utilization of Finite Element Analysis (FEA) has emerged as a crucial methodology in the field of structural and elasticity analysis, facilitating researchers in their understanding of material responses to diverse thermal or structural loads. This study investigates the utilization of FEA to simulate the Impact characteristics of titanium composites, with specific emphasis on the Charpy impact test. The research utilizes the Abaqus Explicit software, which is widely recognized for its explicit dynamic analysis functionalities, to simulate high-speed and short-duration events such as impacts. The primary objective of this study is to examine the impact behavior of Ti–7Al–1mo/TiN composites fabricated through the spark plasma sintering technique. The impact behavior is simulated using FEA, wherein the shear failure model is utilized to replicate fracture phenomena. This paper examines the methodology employed in the FEA approach, with a particular focus on various factors including boundary conditions, explicit dynamic analysis settings, and material properties. Results: The outcomes and analyses involve the examination of the von Mises stress distribution, displacement magnitude, and energy behavior of the models that were tested. Reinforcement of Ti–Al–Mo ternary alloy with TiN led to a progressive increase in maximum von Mises stress, reaching a peak at 3 wt% TiN. Conversely, displacement magnitude decreased with increasing TiN content, with CP-Ti and the unreinforced alloy exhibiting the highest values. Absorbed energy also declined with higher TiN levels. While models containing 5 and 7 wt% TiN displayed limited plastic deformation before fracture, composites with ≤ 3 wt% TiN maintained acceptable ductility despite enhanced strength and stiffness. Conclusion: The FEA methodology effectively simulates the Charpy impact characteristics of Ti–7Al–1Mo/TiN composites, thereby offering significant contributions to understanding their mechanical behaviors. These findings suggest that TiN reinforcement up to 3 wt% presents a promising strategy for improving the mechanical performance of Ti–Al–Mo alloys while minimizing the trade-off in toughness. This research emphasizes the inherent trade-off between toughness and strength/stiffness, suggesting the possibility of optimizing the composition of materials to suit particular applications. This study makes a valuable contribution to the expanding field of impact behavior research, demonstrating the potential of FEA, specifically utilizing Abaqus Explicit software, for enhancing material design and evaluation. [ABSTRACT FROM AUTHOR]

Devices used in power electronics, such as those powered by GaN, SiC, and other wide band gap semiconductors, can reach very high temperatures (beyond 250°C). A high melting point and high thermal and electrical conductivity are required for the die attach material. Traditional solder materials for packaging cannot be used for these applications, as they do not meet these requirements. Sintered nano-silver is a good candidate because of its high thermal and electrical conductivity and very high melting point. The high-temperature operating conditions of these devices lead to high thermomechanical stresses that adversely affect performance and lead to failure. A number of these devices are mission-critical and require high reliability. It is difficult to build test vehicles in the lab that are close to production quality, and therefore, making comparisons or predictions becomes difficult. Virtual testing using a finite element analysis (FEA) technique can serve as a good alternative. In this paper, a nonlinear coupled thermal and mechanical analysis is conducted for a given assembly. Damage and fatigue analysis are carried out for multiple thermal cycling conditions. The results are compared with the actual results from an experimental study. A Coffin–Manson type power law relationship is developed to help determine the accelerated aging conditions and predict life for various service conditions. The paper shows how a detailed reliability assessment can be conducted reasonably quickly and without significant cost, by using high-fidelity elastic–plastic FEA simulations to determine inputs for analytical fatigue reliability models. [ABSTRACT FROM AUTHOR]

Nowadays, active human body models are becoming essential tools for the development of integrated occupant safety systems. However, their broad application in industry and research is limited due to the complexity of incorporated muscle controllers, the long simulation runtime, and the non-regular use of physiological motor control approaches. The purpose of this study is to address the challenges in all indicated directions by implementing a muscle controller with several physiologically inspired control strategies into an open-source extended Hill-type muscle model formulated as LS-DYNA user-defined umat41 subroutine written in the Fortran programming language. This results in increased usability, runtime performance and physiological accuracy compared to the standard muscle material existing in LS-DYNA. The proposed controller code is verified with extensive experimental data that include findings for arm muscles, the cervical spine region, and the whole body. Selected verification experiments cover three different muscle activation situations: (1) passive state, (2) open-loop and closed-loop muscle activation, and (3) reflexive behaviour. Two whole body finite element models, the 50th percentile female VIVA OpenHBM and the 50th percentile male THUMS v5, are used for simulations, complemented by the simplified arm model extracted from the 50th percentile male THUMS v3. The obtained results are evaluated additionally with the CORrelation and Analysis methodology and the mean squared error method, showing good to excellent biofidelity and sufficient agreement with the experimental data. It was shown additionally how the integrated controller allows simplified mimicking of the movements for similar musculoskeletal models using the parameters transfer method. Furthermore, the Hill-type muscle model presented in this paper shows better kinematic behaviour even in the passive case compared to the existing one in LS-DYNA due to its improved damping and elastic properties. These findings provide a solid evidence base motivating the application of the enhanced muscle material with the internal controller in future studies with Active Human Body Models under different loading conditions. [ABSTRACT FROM AUTHOR]

Purpose: In this paper, dynamic behavior of a rotor system with an elliptical breathing crack that simulates the real shape of the crack front is investigated. Methods: A finite element model of the cracked rotor system is developed. The crack breathing mechanism is modelled based on an improved breathing model which considers the inclination of the neutral axis of the cracked element cross-section during shaft rotation. Harmonic balance method is used to solve the equations of motion of the rotor system for steady-state response characteristics. The effect of some parameters such as crack depth, crack shape factor and the spinning speed is investigated. Results and conclusions: The results show that the unique whirl orbits behavior during passage through the subcritical speeds serve as a key indicator of crack presence in the shaft. The effects of the crack front curvature and the breathing model are revealed. The value of shape factor affects the whirl orbit characteristics such as size of the inner or outer loops and the amount by which the orbits rotate while crossing the subcritical speeds. The presented model considering the real crack front shape may contribute towards improved modelling of cracked rotors and better interpretation of measured vibration response. [ABSTRACT FROM AUTHOR]

In this paper, the deformation response of the stratum in the vicinity of a tunnel is investigated based on a case study in Tianjin. A method to predict the surface settlement in the case of double-track curvature shield tunneling is also proposed. The research methodology consists of analytical calculations, finite element analysis as well as field monitoring. Straight shield tunneling and curvature shield tunneling are modeled, each with a single-track shield and a double-track shield, and their operational parameters are compared. The influence of overcutting and existing tunnel on ground movement is also discussed. The salient observations from the series of analyses are as follows: (a) The maximum settlement induced by curvature shield tunneling is much greater than that induced by straight shield tunneling, while the existing tunnel has little impact on stratum settlement in contrast, (b) the proposed method of predicting the surface settlement induced by double-track curvature shield tunneling fits well with the field-monitored data in the Tianjin case study, and (c) the location of the maximum ground settlement is deviated by the overcutting phenomenon, whereas the settlement of the soil above the excavated tunnel is reduced due to the presence of the existing tunnel. [ABSTRACT FROM AUTHOR]

This paper presents some results achieved in the ultra-precision manufacturing, microelectronics engineering, as well as bioengineering applications of vibration-assisted swing cutting (VASC) technology, and describes the resolved and unresolved challenges presented by VASC manufacturing. In particular, it outlines the residual-height between adjacent trajectories in EVC process technology cannot be eliminated, which has the effect of alleviating this problem. Based on matrix-based compliance modeling, the stroke of the PZTs and the allowable stress of the material on the work-space were analyzed. Theoretical modeling was validated by finite element analysis (FEA). The results showed that the max-stroke of the PZTs and the Von Mises stress could reach up to 16.67 μm and 196.6 MPa in the theoretical, respectively. The max-stroke of the PZTs and the Von Mises stress could reach up to 19.50 μm and 158.9 MPa in the finite element analysis, respectively. Cutting experiment was carried out on the basis of VASC design and modeling, which further verified the large work-space and the VASC technology can suppress residual-height between adjacent trajectories effectively. Thus, the superior performances and easily achievable high surface machining accuracy well facilitate practical applications of the VASC system in micro-/nano machining. [ABSTRACT FROM AUTHOR]

Residual stress is an important factor that affects the properties of cold spray coatings. The study performed 2D single-, 3D single-, and 3D multiple-particle finite element simulations based on the Eulerian method, and hole drilling measurements to study residual stress in cold-sprayed copper coatings. The study examined how the basic modeling parameters affect residual stress in the 2D system. It found that the mesh size, substrate dimension, and simulation duration change the residual stress; while material failure does not have much effect because failure is localized. It also found that thermal softening, which occurs when the initial temperature and/or plastic deformation increase, helps to reduce the residual stress. In addition, the residual stress along the axisymmetric axis of the particle changes from being compressive at first to being compressive-tensile-compressive along the through-depth thickness direction with the interfacial stress being tensile that mainly originates from friction shear of the interfacial layers. For the 3D single-particle simulations, the average residual stress to the through-depth thickness shows tension to compression transition and is similar to the 2D cases. For the 3D multiple-particle simulations, the residual stresses in the coatings/substrate are all compressive because of the repeated and strong impact of the particles, which agree with the experimental measurements. The study also found that the compressive stresses decrease when the coating thickness increases because of more plastic deformation-induced thermal softening. This paper clarifies the effects of Eulerian-based finite element parameters on simulating residual stress in cold spray and will serve as a valuable reference for future studies. [ABSTRACT FROM AUTHOR]

Steel tubes are widely used in structural and industrial applications such as building columns, railings, scaffolding, electrical conduits. During their life cycle, these structures often experience sustained loads, aggressive environmental conditions (such as corrosion), and extreme loading conditions (impact load, blast load and fire exposures). Among these, impact loads have been identified as a critical factor, rendering the structures vulnerable and compromising their overall integrity. To assess the impact performance of these structures, two widely used methods are the pendulum hammer and drop hammer test setups. Despite past studies investigating the effect of impactor geometry on hollow steel tube structures, there exists a lack of collaborative research that comprehensively analyzes the combined influence of various loading parameters (such as impactor mass and impactor height) and structural parameters (including steel yield strength, boundary conditions, and tube diameter) in conjunction with impactor geometry on the impact response of hollow circular steel (HCS) tubes. This paper aims to bridge this gap by conducting a numerical study using nonlinear finite element analysis with the ABAQUS/Explicit package. The impact is simulated at the midspan of the specimens. Three distinct drop hammer shapes (cylindrical, hemispherical, and wedge) are employed, and the analysis considers the material similarity of the drop hammer. The study's findings reveal that the primary failure mode was local buckling at the impacted site, and the impact performance of the HCS tubes is significantly influenced by the yield strength of the steel tube and loading parameters, while boundary conditions have a negligible effect. The outcomes of this study will serve as a valuable reference for future analyses and the design of HCS tube subjected to impact loading. [ABSTRACT FROM AUTHOR]

To study the instability and failure mechanism of tunnel face in composite stratum and the evolution law of supporting pressure in the areas with spring, this paper used two different types of transparent soil and a self-designed 3D model test system. Six large transparent soil model tests were carried out by considering different confined water heads of spring and tunnel burial depth. The optical laser and high-speed camera were controlled to move on a high-precision linear platform. CT scanning was performed to obtain the failure model under different conditions. The finite element method considering a two-way fluid–structure coupling was used to validate the model test. The research results indicate under spring, the support pressure curves can be divided into three stages: rapid decline, rebound-rise, and constant. There is no rebound-rise stage under the condition of no spring. With increased confined water heads or reduced tunnel burial depth, limit support pressure shows an increasing trend. 2D and 3D damage models for different working conditions were obtained by PIV technology and 3D reconstruction technology. If there is a spring, the maximum displacement moves to the top of the tunnel with the increase of water head and the failure mode is a combination of "silo shape" and "inverted prism". When there is no spring, the maximum displacement appears at the interface of the soil layer, and the failure mode is a combination of "silo shape" and "wedge shape". The presence or absence of springs and the change of the confined water head have no significant effect on the height of the loosening area. With the tunnel burial depth ratio of 0.5 to 2.0, the height of the loose area increases from 0.17 to 0.83 D, and the soil arch area develops outward. [ABSTRACT FROM AUTHOR]

The crown pillar in the stope structure belongs to the category of thick plate, and its thickness determines the stability of the engineering structure. The key to determining the safe thickness of the crown pillar lies in solving its deflection function. Previous researchers often used the Galerkin method and other methods except the Ritz method to solve the deflection function of the crown pillar under simple boundary conditions. However, these methods are difficult to solve for the deflection function of the crown pillar under complex boundary conditions. Therefore, this paper builds upon the Reissner plate theory and introduces the Ritz method while considering the influence of strain components εz, γyz, and γzx on the flexural deformation of the crown pillar. Thus, the Reissner–Ritz method for solving the deflection function of the crown pillar in the stope is developed. Taking the failure of the crown pillar in stope 27 in the + 280 m section of the Daxin Manganese Mine as an example, firstly, the maximum tensile stress of the crown pillar is compared with its tensile strength to determine the safe thickness of the crown pillar in stope 27. The correctness of the chosen safe thickness for the crown pillar in stope 27 is verified using the Reissner–Ritz method. Then, FLAC3D is used to model and analyze the 8 m thick crown pillar in stope 27, and the accuracy of the Reissner–Ritz method in determining the safe thickness of the crown pillar is verified through finite element analysis. Finally, a comparison is made between the Reissner–Ritz method and the Galerkin method in solving the deflection function of the crown pillar under the uniformly distributed load, considering both simple and complex boundary conditions. The research results show that the Reissner–Ritz method has significant advantages over the Galerkin method in solving the deflection function of the crown pillar under the uniformly distributed load, even under complex boundary conditions. The findings are of great significance for solving the deflection function of thick plates under both simple and complex boundary conditions under the uniformly distributed load and determining the safe thickness of thick plates. Highlights: Based on the Reissner thick plate theory, the Ritz method is introduced, taking into account the influence of strain components εz, γyz, and γzx on the bending deformation of the crown pillar, forming the Reissner–Ritz method for solving the deflection function of the crown pillar in the stope. The range of safe thickness values for the crown pillar is determined based on the thickness-span ratio and safety factor, incorporating engineering experience to finalize the safe thickness of the crown pillar in the stope. The accuracy of the Reissner–Ritz method in determining the safe thickness of the four-sided fixed support crown pillar under the uniformly distributed load is verified through finite element analysis. Comparing and analyzing the calculation results of the Reissner Ritz method with the Galerkin method. [ABSTRACT FROM AUTHOR]

One approach to address climate change is to replace vapor cooling systems with less harmful technologies. Solid-state refrigeration shows promise because it virtually eliminates the use of greenhouse gases. This paper proposes a concept for a barocaloric regenerator tube bank setup using a solid-state refrigerant, specifically encapsulated pure polydimethylsiloxane rubber. We presented the geometric requirements, operating parameters, and thermal performance of this setup. Given the complexity of simulating the full caloric process, we employed a simple two-dimensional finite element analysis to study the transient thermal and fluid phenomena. We discussed the temperature gradient of the active barocaloric matrix over time in the regenerator. For an isostatic pressure of 130 MPa, the best coefficient of performance for refrigeration achieved was 4.7 using a five-tube arrangement. [ABSTRACT FROM AUTHOR]

This paper proposes a design scheme for a wireless power transfer (WPT) system based on multi-relay coils to solve the power supply demand of 500 kV transmission line online monitoring equipment. The relationship between the operating frequency and the coil loss is established to analyze the influence of the number of relay coils and the coil distance on the transmission performance. The particle swarm optimization model is established with transmission efficiency as the optimization objective. The distribution spacing between coils, the working frequency, and the number of coils are optimized. Based on the equidistant arrangement of relay coils, an optimization scheme of non-equidistant arrangement is proposed. Under the condition of the same number of relay coils, the transmission efficiency of the system is increased by 20.56% and has been verified by experiments. In addition, finite element analysis software has simulated the surrounding high-voltage field strength of the WPT system added to the insulators. The results show that the insulators still meet the insulation standards. The simulation and experimental results show that the proposed scheme can effectively meet the power demand of high-voltage line monitoring equipment. [ABSTRACT FROM AUTHOR]

Bio-cementation through microbially induced calcite precipitation (MICP) has the potential to overcome several technical and environmental limitations of conventional cement-based soil improvement techniques. While a significant amount of research has been directed towards better understanding and controlling MICP processes, there is still a lack of multiphysical formulations that can be used for the design of real geotechnical applications in which both the treatment extent and its strength and deformability need to be evaluated. This paper presents the development and application of a comprehensive bio-chemo-hydro-mechanical model that can be used for designing MICP treatments with the finite element method. To overcome the limitations of current approaches based on elasticity, the formulation involves an elastoplastic constitutive model based on Mohr–Coulomb that can predict the strength increase of MICP-improved soils. The model can easily be calibrated with existing experimental results. The scope of model application is demonstrated through the case of a 2D shallow foundation strengthening. Results reveal that the questions of what level of cementation to target and how to distribute cementation efficiently are of equal importance to ultimately serve the needs of specific geotechnical problems, such as those of bearing capacity. [ABSTRACT FROM AUTHOR]

The material properties of high-strength steels deteriorate under fire conditions and depends on the temperature and fire duration. As a time-dependent inelastic strain behavior, the thermal creep effect becomes significant at elevated temperatures and influences the fire resistance of connections. This paper presents numerical studies on the fire response of unprotected extended end-plate connections made of high-strength steels (Q460, Q690 and Q960), explicitly considering the creep effect. Transient state finite element models including or excluding creep were developed using ABAQUS and validated against the experimental results under the restrained sub-framework. The numerical analysis results exhibit a better agreement with the experimental results regarding the deformation ability and failure mode if the creep effect is considered. Thus, creep is a non-negligible effect in investigating the fire performance of end-plate joints. Parametric studies were carried out to quantitatively assess the influence of moment ratio of connection, axial pressure ratio of column, end-plate thickness and heating rates on rotation–time–temperature characteristics and stress distribution. The numerical results show that the magnitudes of bending moment applied on the connection and axial load on the column play crucial roles in evaluating the fire endurance and critical temperatures. However, the effect of end-plate thickness on the fire-structural behavior of extended end-plate connections is negligible. The heating rate has little effect on the critical temperatures of connections. The rotation capacity of high-strength steel extended end-plate connections depends on the failure mode to a large extent. Finally, fire resistance design suggestions for high-strength steel end-plate connections were put forward according to the observations on the parametric studies. [ABSTRACT FROM AUTHOR]

There is an increased demand on the use of microtunnelling for the installation of new buried pipelines. However, the effect of microtunnelling on the performance of pavements is poorly understood. Hence, this paper aims at addressing this gap in knowledge. A robust three-dimensional finite element model that considers the combined influence of the traffic load and microtunnelling has been developed to study the microtunnelling induced pavement settlement. The influence of the stress level and volume change on the behavior of the subgrade, subbase, and base has been considered using the appropriate soil constitutive model. In addition, a parametric study has been carried out to examine the effect of the presence of the traffic load, backfill height, thickness and stiffness of the surface layer, the diameter of the microtunnelling, and shear strength of the subgrade soil on the microtunnelling induced pavement settlement. It has been found that the traffic load has a remarkable influence on the trend of the relationship between the maximum microtunnelling induced pavement settlement and the backfill height. In addition, the percentage increase of settlement due to the presence of the traffic load ranges between 60 and 674%. Moreover, increasing the diameter of the microtunnelling dramatically rises the settlement of the pavement. Furthermore, the stiffness and thickness of the surface layer were also found to affect the microtunnelling induced pavement settlement. Thus, it is necessary to consider the effect of traffic load, microtunnelling diameter, and backfill height in the assessment of the influence of the microtunneling on the response of the pavement. Importantly, the reported results are beneficial to designers working on the assessment of the microtunnelling induced pavement settlement. [ABSTRACT FROM AUTHOR]

This paper presents a novel anti-loosening nut design, called "SL nut". It features an anti-loosening ring with an interference fit with the bolt thread, thereby squeezing the bolt in the radial direction. Using the finite element analysis, the prevailing and loosening resistance torques of the SL nut were investigated during tightening and untightening processes. The nut demonstrated the largest prevailing and loosening resistance torque among the nuts with prevailing torque. Importantly, both torques remained steadily large during tightening and untightening process. The magnitude of the torques can be controlled by adjusting the overlap length of anti-loosening ring. This new type could become a cost-effective solution for a variety of industrial applications. Additionally, the approach we employed could spur further development of anti-loosening nuts. [ABSTRACT FROM AUTHOR]

Damage mechanics models exhibit favorable properties such as the intrinsic influence of stress triaxiality on damage evolution and the prediction of crack initiation as well as propagation leading to structural failure. However, their application requires advanced expertise hindering the transfer of these models into industrial practice, especially since the parameter calibration is a key obstacle. In this paper, a simplified procedure is proposed for a non-local extension of the Gurson–Tvergaard–Needleman model (GTN), which is a highly accepted model for ductile failure of metals. The procedure is iteration free and requires experimental input data from only two standardized tests. The parameters are determined using look-up diagrams created on the basis of systematic simulations and made available for different material behavior covering the majority of ductile metals. Benchmark tests for three different steels are conducted to evaluate the robustness of the proposed procedure. The reliability of the GTN model is validated for all investigated materials. [ABSTRACT FROM AUTHOR]

In this paper, the numerical simulation of the temperature field and welding angular distortion of a 6mm-thick 5A06 aluminum alloy plate was performed by application of the ABAQUS 2018 finite element analysis software. A 3D thermo-mechanical model of the plate under study with account of heat transfer in the arc motion direction was established. The temperature field distribution and welding-induced angular distortion in the welded structure obtained by the simulation were analyzed to minimize the production cost and improve the production efficiency. By analyzing the magnitude and distribution of residual stresses in the welded structure, selecting a reasonable welding process, and optimizing the design to reduce and control the residual stress, the aluminum alloy welded structure can be effectively manufactured. [ABSTRACT FROM AUTHOR]

The improved CFRP-circular steel tube composite truss was proposed to enhance the connection strength of the steel tube and the anchoring strength of the CFRP sheet by setting it with a thick-walled steel tube at both ends of the members. To investigate the mechanical performance of these novel composite members when used in truss structures, parametric finite element analysis was conducted on the mechanical performance of the composite truss in this paper. The typical stress state of the steel truss, the conventional composite truss, and the improved composite truss were compared in detail. The effect of the number of CFRP layers and the layout of the improved CFRP-steel tube composite member (CFRP-STCM) on the mechanical performance of the composite truss is also incorporated. The analysis results reveal that the thick-walled steel tube can effectively decrease the interfacial stress and hence increase the load-bearing capacity of the composite truss. The load-bearing capacity of the improved composite truss was 53.4 and 28.1% higher than that of the steel truss and the corresponding conventional composite truss, respectively, and has better ductility. The number of CFRP layers and the arrangement of the improved composite members had a great effect on the load-bearing capacity and ductility of the truss. Replacing the weakest compressive braces of the steel truss with the improved composite member can significantly improve the load-bearing capacity and ductility of the truss. The feasibility of the improved composite truss was validated by the refined parametric finite element analysis. [ABSTRACT FROM AUTHOR]

Background: The direct-drive linear motor system is usually a low-damping system, which will cause residual vibration and deteriorate the accuracy of the equipment especially in the high-speed start-stop motion. Purpose: By employing an eddy current damper (ECD), the residual vibration can be effectively reduced. However, the ECD secondary is normally made of a pure copper plate with low magnetic permeability, resulting in low airgap magnetic density and therefore small damping force. In this paper, a dual-sided hybrid excitation ECD which implements high-conductivity and high-permeability plate as the secondary is proposed to enhance the vibration suppression for the linear motor system. Methods: An analytical model is developed to quantitatively analyze the relationship between the damping force and the secondary thickness. Three dimensional finite element analysis (3D FEA) is employed to investigate the effects of different secondary materials and the secondary layer thicknesses on ECD performance. Results and Conclusion: Experiments are conducted to evaluate the damping force and the vibration suppression effect of the designed ECD. Compared with the pure copper secondary under the same secondary dimensions, the damping force is increased by 30.5% with the copper-steel-copper secondary, and the peak amplitude of the position error and the settling time of the system are reduced by 1.94 times and 1.80 times, respectively. [ABSTRACT FROM AUTHOR]

Thermal stress is an important factor affecting the abradability of seal coatings. In this paper, the relationship between rub-induced thermal stress and abradability of CuAl seal coating was studied based on thermal–mechanical coupling finite element method using ABAQUS software and a high-temperature and high-speed abradability test rig. The thermal stress simulation results show that the contact friction coefficient and incursion conditions between blade and coating have an important influence on the rub-induced thermal stress of the coating. The peak stress of the coating surface and the coating–casing interface increased with the increase in the friction coefficient when it was in a range of 0.01-0.3, which increased by 192 and 233%, respectively. The peak stress of the coating surface and the coating–casing interface was the minimum when the blade incursion depth and speed were 100 μm and 500 μm/s, which were 406.23 and 313.71 MPa, respectively. The abradability of CuAl seal coating increased with the decrease of coating feed speed when it was in a range of 10-100 μm/s, and the incursion depth ratio decreased from 12.9 to 8.82%. Combined with the high-temperature hardness and residual thermal stress test results, the release of thermal stress from the porous structure and the reduction of hardness during the scraping process are concluded to be the main reasons for maintaining good abradability of the coating. This work has an important reference value for further study of the influence of thermal stress on abradability. [ABSTRACT FROM AUTHOR]

When the car suddenly collides, the webbing bunching phenomenon will occur at the upper guide ring (D-ring) of the height adjuster of the seat belt, causing serious damage to the human chest by local positive pressure. In this paper, finite element method is used to calculate lateral displacement of seat belt. The BP neural network training method was used to fit the relationship between the displacement response and the random parameters, and the reliability function was established. The reliability and reliability sensitivity of random parameters were calculated by first-order second-moment method, and the influence rule of belt guide ring and belt parameters on reliability was obtained, which provided a theoretical basis for the parameter reliability design of safety belt guide ring. [ABSTRACT FROM AUTHOR]

Many studies have been conducted on the simultaneous measurement of temperature and strain of different structures by fiber bragg grating (FBG) sensors for structural health monitoring purposes. However, most of them have used more than one FBG sensor to discriminate between temperature and strain. The present paper utilized the capability of one uniform FBG sensor for simultaneous measurement of strain and temperature in a cantilever beam. It is achieved by simultaneously monitoring the changes in the full width at half maximum (FWHM) and the Bragg wavelength shift of the optical spectrum of the FBG sensor in the proposed experimental setup. Besides, simulations of FBG spectra are performed for a more detailed study using the data achieved by nonlinear finite element analysis. The strain sensitivity of 0.78 and 0.84 pm/με are obtained for the uniform FBGs used in the experiment and simulation. In addition, the results for the temperature sensitivity are achieved at 12 and 14.4 pm/°C, respectively. The experimental and simulation results for detecting FWHM variations and wavelength shifts due to applying strain and temperature were in good agreement with a 6.5% error.Fo6D [ABSTRACT FROM AUTHOR]

This paper introduces a deep learning approach for accurately predicting the position and size of cracks in steam turbine blades using frequency response function data obtained from finite element analysis. Training deep neural networks for crack prediction necessitates an extensive dataset comprising various crack conditions, along with corresponding position and size information. However, obtaining sufficient high-quality and well-balanced experimental data for diverse crack conditions poses challenges. To address this issue, we leverage finite element analysis techniques to effectively amass a large volume of training data. Our methodology involves frequency response analysis, incorporating a crack modeling approach based on node sharing elimination and model order reduction (MOR). Automating this process enables us to efficiently generate a diverse dataset of crack blade frequency response data in a short timeframe, focusing on cracks in a single blade. The collected data is then transformed into two-dimensional image data, including magnitude similarity maps and magnitude frequency response maps, which serve as training data for our convolutional neural network (CNN) model. Evaluation of the CNN model's performance and accuracy for crack position and size prediction highlights its remarkable precision in determining the initiation position and size of blade cracks. Utilizing the proposed prediction model, there was a 95 % probability of accurately predicting the crack position within 3.1 % of the entire airfoil area. Furthermore, successful crack size predictions were achieved for approximately 96.4 % of the entire test dataset within an error range of ±1 mm. This underscores the potential capability of neural network training and crack prediction by leveraging training data derived from the finite element analysis and MOR. Our approach demonstrates promising implications for enhancing steam turbine blade maintenance and structural integrity assessment, as it streamlines data acquisition and provides an efficient solution for predicting critical crack characteristics. [ABSTRACT FROM AUTHOR]

The major concerns of buckling-restrained braced frames (BRBFs) are the low post-yield stiffness and excessive residual displacement, which can delay the post-earthquake recovery procedure and enhance the repair cost. The current numerical work presents an innovative buckling-restrained brace (BRB) including a reduced-length hybrid core that is attached to a robust steel pipe. The core is laterally supported and consists of a shape memory alloy (SMA) rod inserted into a steel pipe. The paper represents a detailed description of the proposed device. The performance of the proposed BRB is numerically investigated at the component level using the ABAQUS finite element package. Subsequently, the system-level response of the proposed device is investigated by nonlinear static pushover and dynamic time history analyses in the OpenSEES environment. The results demonstrate that the proposed device shows a two-stage yielding mechanism, benefits the combined hysteretic responses of the SMA and the steel cores, and exhibits a stable and symmetric cyclic behavior with a nearly flag-shaped hysteresis. Furthermore, compared with conventional BRBs, the proposed device reduces the maximum inter-story and particularly the problematic residual drift responses of the BRBFs. Additionally, by an increase in the total area of the SMA core, though the maximum inter-story drift response is slightly increased due to the low elastic modulus of the SMA material, the residual drift response of the BRBFs is further decreased. [ABSTRACT FROM AUTHOR]

Part of power transformers failures are result of great electromagnetic forces acting on its windings due the circulation of high currents, as in case of short circuits. To contribute for a more reliable mechanical design, this paper presents a finite element analysis (FEA) for a complete calculation and evaluation of electromagnetic forces on transformers windings. Three arrangements of concentric windings are analyzed considering three-phase and three-dimensional models, dealing with issues as the influence of magnetic core window and lateral phases presence, ensuring more accurate results. The adopted modeling allows to determinate the total axial and radial forces on all the phases and its distribution over the height of windings and around the core leg. It was possible to identify points of greater and lesser forces and the behavior of forces on different constructive arrangements, allowing its choice improvement during the design stage. The results present good agreement to the analytical method, allowing the application of the developed FEA for transformer design optimization, contributing for a time and costs reduction and avoiding future mistakes in its construction and failures during its operation. [ABSTRACT FROM AUTHOR]

The present paper aims to investigate the effects of defective piles in horizontally loaded piled raft foundations. Close to real scale foundation models of defective and intact three-piled systems were submitted to horizontal load tests. The models used bored type piles drilled with 5 m in length and 0.25 m in diameter, connected to a concrete raft founded on a tropical soil profile at the University of Campinas research site. Based on the experimental data, a three-dimensional finite element analysis was initially calibrated and consequently used to study the effects of the defective element at the pile load distribution and the horizontal subgrade forces at the pile shaft. The results show that the presence of a defective pile increases the raft tilting, which affects both vertical and horizontal load distributions among the raft and the piles, and among trailing and leading piles. [ABSTRACT FROM AUTHOR]

Due to high precision, high speed, and high fault tolerance capability, the linear switched reluctance motor (LSRM) is applied in digital control technologies as well as electronic switching devices. The LSRM is considered as a good substitute for conventional linear drive systems for long-way transportation. In this paper, a single-stator and double-stator longitudinal flux-type LSRM for high-speed transit system is proposed. Since the flux in the longitudinal arrangement is in the same alignment as the motion of the translator, the proposed system is easier to construct, mechanically stable with minimum eddy current loss. It also produces the magnetic flux along the direction of motion, which makes it highly suitable for high-speed linear transit application. The proposed conceptual LSRM differs from the conventional LSRM, in such a way that the active stator holds the excitation windings, while at the same time it acts as a translational body that moves over the stationary translator bed. The motor characterization is performed in ANSYS electromagnetic simulation tool, to determine the applied forces, coupling inductance, and strength of the magnetic field of the proposed LSRM for the traction propulsion system. The finite element analysis (FEA) is utilized here to analyze the modeled configuration, for verification of the design and performance prediction of the proposed LSRM. [ABSTRACT FROM AUTHOR]

This paper uses finite element analysis to investigate the plastic deformation and metal flow of metal powder in open-die and closed-die rotating compression forming processes. In the closed-die rotating compression forming process, the effects of forming temperature, compression pressure, rotation speed, rotation lap number, and alternating rotation frequency on the relative density and effective strain distributions inside the product are discussed. In the open-die rotating compression forming process of powder materials, the top die is controlled by speed. The effects of alternating frequency on the rotating torque, axial load, bulging ratio, and relative density are discussed. A rotating compression machine is designed and manufactured. Experiments of rotating compression forming of aluminum alloy A1050 powder material are also conducted. The hardness distributions are measured and the metallographic microstructures are observed. The measured relative density and hardness distribution are compared with the simulation results to validate the finite element modelling of rotating compression forming of aluminum powder materials. [ABSTRACT FROM AUTHOR]

Under earthquake loads, reinforced concrete chimneys with openings are prone to stress concentration and damage around these openings, possibly leading to structural collapse. In this paper, the stress concentration factor was proposed to quantitatively analyse the range of stress concentrations around openings under various parameters and identify the most significant coefficients affecting the stress concentration range. 9 Groups of numerical analysis models for chimneys with different parameterized openings were established, and more than 200 pushover analyses were conducted. The effects of the chimney wall thickness, wall diameter, opening size, and spacing between openings on the stress around the openings were investigated. Recommendations for limiting opening sizes were given, and a method for designing reinforcement steel bars for strengthening was proposed. The numerical results indicated that the central angle of a single opening cross-section should be less than 70°, and the total central angle of multiple openings should be less than 140°; the spacing between openings should not be less than 0.5 times the width of the opening; the range of the steel reinforcement range should be 4.5 times the wall thickness for circular openings; and for rectangular openings, it should be 3.5 times the wall thickness. The added reinforcement steel should have a reinforcement ratio for strengthening of 1.3 times that of the original reinforcement ratio. Finally, through dynamic analysis, it was verified that the opening reinforcement design method proposed in this paper can effectively reduce the stress concentration around openings. [ABSTRACT FROM AUTHOR]

In this paper, dynamic buckling analysis of composite cylindrical panels under two separately suddenly applied loads (axial compression and lateral external pressure) is investigated. Abaqus/Explicit operator has been used to monitor time responses of the structure under various magnitudes of loads in order to determine the critical dynamic buckling loads based on the Budiansky–Roth criterion. The effect of boundary conditions and loading duration is studied thoroughly in this work. [ABSTRACT FROM AUTHOR]

In this paper, the effects of strain rate on the mechanical properties of DP780 were analyzed by quasi-static tensile test and Hopkinson bar test; Johnson-Cook constitutive model with high strain rate was established. Based on ANSYS/LS-DYNA finite element program, the finite element simulation of electromagnetic forming process of high-strength steel sheet under the action of driving plate was realized, and the influence of various process parameters on the forming height was studied. The results showed that the yield strength and ultimate tensile strength of the material increased with high strain rate, and DP780 high-strength steel had certain strain rate sensitivity. The drive sheet receives the maximum magnetic field force near the outermost two-turn coil. The deformation of high-strength steel plate mainly occurs under the action of impact inertia. The peak forming height increases with the rise of discharge frequency. The increase of the thickness of the drive sheet can reduce the forming efficiency. [ABSTRACT FROM AUTHOR]

Bus rollover accidents are receiving increasing attention due to the associated high fatality rate. In order to improve the bus structural performance during the rollover collision, it is necessary to investigate how the impact force is transferred within the bus superstructure. This paper introduced a method for studying the load transfer behavior of the bus superstructure during the standard rollover test by using the U * M index. A bus bay section was used as the sample structure to demonstrate the proposed method. The result of the paper reveals that the load transfer analysis based on the U * M index can provide engineers with the insight of the structural issues and the direction to improve the structural performance, which cannot be accomplished through the conventional finite element analysis. [ABSTRACT FROM AUTHOR]

Topology optimisation is a process that is becoming increasingly reliable and necessary in the pursuit of highly efficient components comprising of low mass with a high structural performance. These components are typically mass-produced on a large-scale in automotive sectors for instance, where components are usually metallic and pressed. The ability to maximise a component’s structural characteristics has yielded many variations of computational topological solvers over the years. Over time many different methodologies have been used to generate suitable manufacturable solutions. Despite this, a gap between the generation of topology optimisation solutions and the creation of ready-to-manufacture solutions still exists today. This review paper outlines existing methods for computational topology optimisation and addresses any refinement methods used to generate a manufacturable solution, particularly focussing on methodologies used in automotive sheet metal forming. These methods are scrutinised in regards to the level of manual user input needed to create a Computer Aided Design (CAD) model representation of the manufacturable solution. Suggestions are also made to highlight further work to improve these techniques for large-scale industry-standard product development. [ABSTRACT FROM AUTHOR]

Fixture layout has a direct impact on the machining quality of thin-walled parts. However, there are few studies on the flexible fixture of automotive interior decoration, especially for car dashboards. With the development of individualized demand, the production trend of car dashboards is changing from large-quantity to multi-variety and small-batch, which makes the demand for flexible fixture of car dashboards. Therefore, a kind of flexible fixture for car dashboards based on a new N-M principle was proposed in this paper. With the scientific problem illustrated, this paper put forward a method by coupling genetic algorithm and finite element analysis to deal with the flexible fixture layout optimization. The optimization model of fixture layout based on the N-M principle was set up by taking the maximum deformation of car dashboards as the optimization objective and setting constraints. Finite element model was established to calculate the deformation by setting the boundary conditions, the equivalent cutting force. Genetic algorithm was used to search the optimal solution of the fixture layout. A case was studied to verify the method, and the result showed that the maximum deformation was reduced by 56.5% and the stiffness was increased by 0.77 times, which fully demonstrated the effectiveness of the method. [ABSTRACT FROM AUTHOR]

In this paper, a finite element analysis (FEA) based fast optimization method to optimize a lightweight in-wheel switched reluctance machine is presented. This method speeds up the switched reluctance machine optimization procedure by running the FEA simulations with single-phase constant current excitations for half electrical cycle and estimating the machine performance metrics using the gathered FEA data. Hence, the machine's dynamic performance estimation process takes shorter for each design candidate. The optimization algorithm employs designs of experiments (DOE), response surface (RS) analysis method, and differential evolution algorithm (DE). Here, the DOE method is used to reduce the search space by narrowing down the upper and lower boundaries of each design variable based on the RS analysis. Although this process does not guarantee getting the Pareto front, it places the search space close to the actual one. Hence, the multi-objective DE optimization finds the Pareto optimal solution set without requiring a large number of iterations as well as a large number of candidate designs for each iteration. The method is applied to a 24/16 SRM that is intended to be used in a lightweight race car as a hub motor. Six dimensionless geometric variables are optimized to satisfy three objective functions, namely torque ripple, motor mass, and copper loss. While the conventional DE takes at least 3000 candidate designs, the proposed method considers only 559 designs to reach a similar Pareto front. It is observed that the proposed method takes about 6 h 30 min compared to the conventional method that takes 32 h 50 min using the same computer. Therefore, the computation time is reduced almost five times with the proposed method. [ABSTRACT FROM AUTHOR]

Finite element modeling is a precious tool for the investigation of the biomechanics of the musculoskeletal system. A key element for the development of anatomically accurate, state-of-the art finite element models is medical imaging. Indeed, the workflow for the generation of a finite element model includes steps which require the availability of medical images of the subject of interest: segmentation, which is the assignment of each voxel of the images to a specific material such as bone and cartilage, allowing for a three-dimensional reconstruction of the anatomy; meshing, which is the creation of the computational mesh necessary for the approximation of the equations describing the physics of the problem; assignment of the material properties to the various parts of the model, which can be estimated for example from quantitative computed tomography for the bone tissue and with other techniques (elastography, T1rho, and T2 mapping from magnetic resonance imaging) for soft tissues. This paper presents a brief overview of the techniques used for image segmentation, meshing, and assessing the mechanical properties of biological tissues, with focus on finite element models of the musculoskeletal system. Both consolidated methods and recent advances such as those based on artificial intelligence are described. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to design and test the voice coil actuated (VCA) engine mount for vibration reduction in automobile. Due to the VCA engine mount generates a counter force to cancel the abnormal vibration generated when the variable cylinder is working, it is widely known one of the effective methods for reducing vibration delivered by the engine. To reduce the vibration efficiently, the VCA engine mount needs to have fast response, wide range of frequency and large excitation force. In this research, we present a VCA engine mount. Lumped parameter modeling and analysis of the VCA engine mount is performed to theoretical analysis. The dynamic performance of the VCA engine mount such as magnetic force, spring force, displacement and excitation force was verified by finite element analysis (FEA). After manufacturing a prototype, excitation force is experimentally investigated. [ABSTRACT FROM AUTHOR]

This paper is concerned with the isogeometric analysis (IGA) of composite laminates under cylindrical bending. Non-uniform rational B-splines (NURBS) are employed as basis functions for both geometric and computational implementations. In order to account for multiple domains, each lamina is modeled as a single NURBS patch. This multipatch representation corresponds to decomposition of the computational domain (composite laminate) into non-overlapping subdomains. As NURBS patches are discontinuous across their boundaries, a standard FEA-like procedure does not work for multipatch IGA; an additional numerical technique is required for coupling NURBS patches. Therefore, in this paper, one of the discontinuous Galerkin (DG) methods, namely symmetric interior penalty Galerkin formulation, is employed to allow for discontinuities. For numerical calculations, a composite laminate with stacking sequences 0 ∘ / 90 ∘ and 0 ∘ / 90 ∘ / 0 ∘ , respectively, is adopted. The stresses are calculated along the thickness of the composite laminate, subjected to a sinusoidal load, and they are compared with the analytical solutions. It is shown that DG–IGA gives a better approximation in comparison with the standard IGA. [ABSTRACT FROM AUTHOR]

This paper presents the optimal design and performance analysis of a novel synchronous reluctance motor with outer rotor for determination of the effect of the rotor pole shape on the machine's performances. The investigation has been made in order to find the possible ways to improve the power factor with refining the rotor geometry without using permanent magnets. Starting from the design of the machine with classical rotor pole that was implemented in FLUX 2D, a finite element analysis software coupled with an optimal design procedure implemented in MATLAB was performed. The purpose of this complex co-simulation was to obtain several outer rotor structures that increase the performances of the machine: saliency ratio, power factor and torque density. For the proposed structures, especially for the modular topology, the obtained results of saliency and power factor have never been presented in the past literature. Hence, this represents a useful starting point for the following analysis of outer rotor synchronous reluctance machines with improved power factor. [ABSTRACT FROM AUTHOR]