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In order to effectively mitigate the micro-vibration energy from the on-orbit flywheel and high-level vibration transmitted to flywheel system in the launching stage, a nonlinear vibration absorber (NVA) with Euler-buckled beams is developed and investigated in this paper. The NVA is composed of a linear supporting spring and a set of parallel Euler-buckled beams which is used as a negative stiffness corrector. In order to evaluate vibration reduction performance and stability characteristics of this developed nonlinear coupled dynamic system with NVA. First of all, a multi-degree-of-freedom compound dynamic model, including the flywheel system, the NVA and the supporting structural plate in the satellite platform, is built. Then, based on the systematic dynamic equations, the approximate steady-state solutions are derived by using the complexification-averaging (CX-A) method under on-orbit and launching loads, respectively. The analytical method and solutions are validated by using the numerical method. The proposed NVA can realize excellent vibration mitigation performance for the three-degree-of-freedom (3-DOF) coupled nonlinear system under the launching and on-orbit excitations. Next, the slow-variable manifold equation is analyzed to address the dynamic bifurcation behaviors of the nonlinear compound system and the influences of the excitation amplitude on the bifurcation characteristics are focused on. The results show that a 3-DOF system is more prone to instability and requires larger external excitation to escape the instability region. The calculation results also show that the stiffness ratio and excitation amplitude have significant effects on the bifurcation characteristics, and a proper stiffness ratio can be chosen to avoid bifurcations. Finally, compared with typical pure cubic stiffness NVA, the proposed NVA exhibits greater adaptability, and can work efficiently for a relatively larger range of excitation amplitude. [ABSTRACT FROM AUTHOR]

As a metal additive manufacturing process, laser cladding (LC) is employed as a novel and beneficial repair technology for damaged steel structures. This study employed LC technology with 316 L stainless steel powder to repair locally corroded steel plates. The influences of interface slope and scanning pattern on the mechanical properties of repaired specimens were investigated through tensile tests and finite element analysis. By comparing the tensile properties of the repaired specimens with those of the intact and corroded specimens, the effectiveness of LC repair technology was assessed. An analysis of strain variations in the LC sheet and substrate during the load was carried out to obtain the cooperation mechanism between the LC sheet and substrate. The experimental results showed that the decrease in interface slope slightly improved the mechanical properties of repaired specimens. The repaired specimens have similar yield strength and ultimate strength to the intact specimens and better ductility as compared to the corroded specimen. The stress–strain curve of repaired specimens can be divided into four stages: elastic stage, substrate yield-LC sheet elastic stage, substrate hardening-LC sheet elastic stage, and plastic stage. These findings suggest that the LC technology with 316 L stainless steel powder is effective in repairing damaged steel plates in civil engineering structures and that an interface slope of 1:2.5 with the transverse scanning pattern is suitable for the repair process. [ABSTRACT FROM AUTHOR]

Functionally graded materials (FGMs) are revolutionizing various industries with their customizable properties, a key advantage over traditional composites. The rise of voxel-based 3D printing has furthered the development of FGMs with complex microstructures. Despite these advances, current design methods for FGMs often use abstract mathematical functions with limited relevance to actual performance. Furthermore, conventional micromechanics models for the analysis of FGMs tend to oversimplify, leading to inaccuracies in effective property predictions. To address these fundamental deficiencies, this paper introduces new gradation functions for functionally graded beams (FGBs) based on bending strain energy density, coupled with a voxel-based design and analysis approach. For the first time, these new gradation functions directly relate to structural performance and have proven to be more effective than conventional ones in improving beam performance, particularly under complex bending moments influenced by various loading and boundary conditions. This study reveals the significant role of primary and secondary gradation indices in material composition and distribution, both along the beam axis and across sections. It identifies optimal combinations of these indices for enhanced FGB performance. This research not only fills gaps in FGB design and analysis but also opens possibilities for applying these concepts to other strain energy density types, like shearing and torsion, and to different structural components such as plates and shells. [ABSTRACT FROM AUTHOR]

Plates and curved plates are essential components in ship construction. In the design stage, the methods used to evaluate the ultimate strength required to confirm the structural safety of plates include prediction through analytical methods, finite-element analysis (FEA), and empirical formulas. However, with nonlinear buckling, the results of the empirical formula and the FEA differ for small flank angles (1~9). As a result, the prediction of the nonlinear ultimate strength of flank angle (1~9) plates still requires significant computation time and cost. To compensate for this, this study performed an ultimate strength prediction method utilizing a deep neural network together with the 4050 curved plate analysis. In addition, this paper presents the analysis results of the nonlinear finite-element method and the geometric shape and ratio of curved plates as training data. Based on the results of this study, designers can more efficiently design appropriate curved plate members by considering the ultimate strength. [ABSTRACT FROM AUTHOR]

This paper discusses a system designed to process parameter settings for achieving optimum cutting quality by a Computer Numerical Control (CNC) Plasma Machine, employing the Jaya algorithm. The aim is to obtain the most optimized parameter settings for the CNC Plasma Machine, focusing on the plasma cutting method applied to commonly used metals, 304 stainless steels, and S235. The investigation centres on understanding the impacts of these parameters on surface roughness (Ra) and tapper angle. The experiments, conducted using Full Factorial Design (FFD), involved mathematical prediction models developed through a regression method with three controllable levels for each parameter on 12mm S235 steel and 304 stainless steel plates. The Jaya algorithm, known for its efficiency in engineering optimization, operates on the principle of gravitating towards positive outcomes while avoiding unfavorable ones. What sets this study apart is the utilization of the Jaya algorithm, a sophisticated optimization tool that demonstrated exceptional efficiency by converging to the optimum solution within a mere 15 iterations. The Jaya algorithm's robust performance was highlighted through a comparative analysis, positioning it as superior to alternative techniques for delivering the best optimum solution in a remarkably reduced number of iterations. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiao Tong University (1006-2467) is the property of Journal of Shanghai Jiao Tong University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Inspired by the desire to solve a series of problems such as the easy mottling and peeling of the physically attached artificial interfacial layer on the surface of Zn anode, ZnSiO 3 with a nanosheet morphology was constructed on the surface of Zn foil through the self-growth reaction. The ZnSiO 3 nano-interfacial layer effectively slices the surface of the Zn foil into individual microscopic interfacial layers, and this study provides a new perspective for the interfacial engineering of the protection of Zn anodes. [Display omitted] Among battery technologies, aqueous zinc ion batteries (AZIBs) have hit between the eyes in the next generation of extensive energy storage devices due to their outstanding superiority. The main problem that currently restricts the development of AZIBs is how to obtain stable Zn anodes. In this study, taking the improvement of a series of problems caused by the physically attached artificial interfacial layer on Zn anode as a starting point, a nanosheet morphology of ZnSiO 3 (denoted as ZnSi) is constructed by self-growth on Zn foil (Zn@ZnSi) by a simple hydrothermal reaction. The ZnSi nano-interfacial layer effectively slices the surface of the Zn foil into individual microscopic interfacial layers, constructing abundant pores. The nanosheets of Zn@ZnSi construct rich nanoscale Zn2+ transport channels, which provide higher electron and ion transport paths, thus achieving the effect of effectively homogenizing the electric field distribution and decreasing the local current density. Thanks to its inherent and structural properties, the Zn@ZnSi anode has a high specific capacity and good cycling stability compared with the Zn electrode. The lifetime of the Zn@ZnSi//Zn@ZnSi symmetric cell is much higher than that of the Zn//Zn symmetric cell at 1 mA cm−2. The capacity of the Zn@ZnSi//NH 4 V 4 O 10 full cell can still reach 98 mAh g−1 after 1000 cycles at 1 A/g. The low-cost and scalable synthesis of ZnSi nano-interfacial layer on Zn is expected to provide new perspectives on interfacial engineering for Zn anodic protection. [ABSTRACT FROM AUTHOR]

Fiber lasers, the latest laser-cutting technology, are notable for their high process efficiency, cutting precision, and high cutting quality for thin materials. However, the quality of the cut significantly decreases when machining thicker materials. For now, this is a challenge for the metalworking industry. This study investigated the effects of laser power, cutting speed, and auxiliary gas pressure on the fiber-laser cutting quality of 4 and 6 mm thick S355JR steel plates. To evaluate the influence of cutting parameters on cutting quality, surface roughness, dimensional accuracy and cut taper were measured. A microscopic analysis of the laser cuts was performed, revealing the heat-affected zone, transition zone and unaffected base-material zone. Research results show that laser cutting is a complex process, and the correct choice of cutting parameters greatly influences the cutting performance and final quality. An artificial neural network was created and trained using the results from measuring the quality characteristics to achieve optimum cutting quality. The accuracy of the optimization model was assessed by control samples, which were cut using calculated optimum parameters. The actual values of the quality characteristics only slightly differ from the predicted values, showing that the optimization model is suitable for selecting cutting parameters. [ABSTRACT FROM AUTHOR]

Culvert is an important part of railway, and it is also the most neglected railway equipment in daily maintenance. The deterioration and mechanical performance of culvert structure directly affect the safety and stability of the line. Aiming at the problems of insufficient bearing capacity, excessive settlement, dislocation and durability reduction of heavy haul railway culverts under the condition of speed-up reconstruction, this paper conducts the mechanism analysis of culvert reinforcement with assembled corrugated plate, the performance analysis and sensitivity analysis of culvert reinforcement with key parameters of corrugated plate and the practical engineering application technology of culvert reinforcement with corrugated plate based on the methods of finite element analysis, test detection and engineering application. The results show that the overall stiffness of the culvert structure is significantly improved, the stress and deformation of the culvert roof are significantly reduced, and the reinforcement effect is better after using corrugated plate reinforcement technology. Under the same size condition and compared with the rectangular and triangular corrugated plate structures, the maximum vertical displacement and maximum stress value of the roof span can be reduced by 20% or more after the culvert is reinforced by the circular arc corrugated plate, and the circular arc corrugated plate has better reinforcement effect. Under the combined load of the main force, with the increase of the wave height and wave distance of the corrugated plate, the Mises stress of the corrugated plate decreases gradually, and the Mises stress is inversely proportional to the span of the culvert. The field test results of 16 culverts show that the stress and deformation of culverts with different spans and frame culverts are significantly reduced after corrugated plate reinforcement, and the mid-span deflection and dynamic strain are reduced by more than 40% compared with those before reinforcement. Corrugated plate technology has a good reinforcement effect in the culverts of heavy haul railway. [ABSTRACT FROM AUTHOR]

As one of the protective components, the high strength low alloy structural steel plate had attracted extensive attention because of frequent threats of explosive loads. In this paper, combining explosion experiment, finite element model (FEM) and multi-scale microscopic observation technique, the relationship between macroscopic dynamic response and microscopic damage of low alloy steel plate under the close-range explosion (i.e., 2 cm, 3 cm, 6 cm, and 10 cm) was investigated. After the explosion experiments and validation of the FEMs of the four steel plates, the thickness sections of the position closest to the explosives were selected for microscopic observation of different scales. According to the observation results, the defects were characterized and mainly divided into four damage types. Subsequently, based on the numerical simulation data and microscopic observation results, three models were established to describe the change rules of impulse-explosive distance (I-E), texture-explosive distance (T-E), as well as impulse-texture (I-T), respectively. The results showed that when the explosive distance was 2–10 cm, I-E and T-E were consistent with the quadratic fit. In addition, the texture of base material (BM) was 3.42, which was 2.36 times larger than that of closest explosive distance sample. The variation law of I-T better revealed the relationship between the macroscopic dynamic response and microscopic damage with different explosive distances which agreed with the linear model. These results can be used to predict and prevent damage propagation of low alloy steel plate under the close-range explosion and improve the protective ability of protective materials. [ABSTRACT FROM AUTHOR]

This research presents a first attempt to analytically determine the asymmetric dynamic transverse characteristics of thin to moderately thick viscoelastic functionally graded porous (VFGP) annular plates. Firstly, the material properties of the plate are assumed to have various nonlinear distributions in terms of porosity coefficient. Secondly, the motion equations are obtained through the first-order shear deformation theory (FSDT) of elasticity, the energy method, and the variations calculus. Thirdly, the standard linear solid (SLS) model is adopted to consider the viscoelastic behavior of the plate. Finally, the perturbation procedure together with Fourier series are utilized to solve the system of partial differential equations, and the asymmetrically dynamic response is found in a closed-form solution. To assess the veracity of the analytical findings, an algorithm based on the finite element (FE) method called the user-defined field (USDFLD) code is developed. In order to benchmark the present study, the dynamic response of VFGP annular plates is scrutinized under two types of excitations (impulsive and step), four different types of radial load profiles (such as constant, linear, parabolic, and sine distributions), and various asymmetric circumferential loads. Moreover, the influence of various geometrical and material characteristics on the dynamic response of VFGP annular plates is investigated. [ABSTRACT FROM AUTHOR]

This research paper investigates the thermal stratification and chemical reaction effects on MHD Flow through oscillatory vertical plate in a porous medium with temperature variation and exponential mass diffusion. Through the application of the Laplace transform method, the paper derives analytical solutions that precisely depict the physical dynamics of the flow. The investigation utilizes sophisticated mathematical models to scrutinize the complex dynamics between Magnetohydrodynamics (MHD) and convective movements, considering a range of conditions involving temperature fluctuations and exponential rates of mass diffusion. A pivotal finding from this research is the detailed comparison between the outcomes of thermal stratification and those observed in environments lacking such stratification. It is observed that the implementation of stratification within the flow leads to a more rapid achievement of equilibrium or steady-state conditions. [ABSTRACT FROM AUTHOR]

We have explored the exponential surface brightness profile (SBP) of stellar disks, a topic extensively discussed by many authors yet seldom integrated with the study of correlations between black holes, bulges, and entire disks. Building upon our prior work in the statistical mechanics of disk-shaped systems and aligning with methodologies from other research, we analyze the influence of the central body. This analysis reveals analytical relationships among black holes, bulges, and the entire stellar disk. Additionally, we incorporate a specific angular momentum distribution (SAMD) that aligns more closely with observational data, showing that for the self-gravitating disk, with the same surface density, a reduction in its spin results in only a slight decrease in its radius, whereas with the same SAMD, an increment in its spin significantly limits its extent. A key feature of our model is its prediction that the surface density profile of an isolated disk will invariably exhibit downbending at a sufficient distance, a hypothesis that future observations can test. Our refined equations provide a notably improved fit for SBPs, particularly in the central regions of stellar disks. While our findings underscore the significance of statistical mechanics in comprehending spiral galaxy structures, they also highlight areas in our approach that warrant further discussion and exploration. [ABSTRACT FROM AUTHOR]

This research focuses on the experimental investigation of the low-cycle fatigue characteristics of marine structural steel. The study aimed to explore the behavior of marine-grade steel under low-cycle fatigue conditions. The experimental parameters include the fatigue life of the material, crack propagation behavior, and a comprehensive analysis of mechanical properties associated with various loading conditions. Based on the experimental results, a low-cycle fatigue crack propagation rate model for marine structural steel plates was established using CTOD as a characterization parameter. The primary objective of this research is likely to enhance the durability and safety of maritime structures, providing valuable technical insights for the field of naval engineering. [ABSTRACT FROM AUTHOR]

The analysis of variable-thickness plates is much more complicated than that of uniform-thickness plates because variable coefficients occur in the equations. In reality, this analysis is of great interest in various engineering disciplines, such as civil engineering, aerospace engineering, machine design, and so on. Although there is extensive literature on analyses of plates with constant thickness, a rather limited amount of technical literature is available on the solutions to problems dealing with plates wi th nonuniform thickness. The reason is that the analytical solutions meet insurmountable difficulties. Besides, the nonlinear analysis process also faces more difficulties than the linear analysis of structures. For these reasons, the nonlinear behavior of variable-thickness plates based on a finite element procedure is presented in this study. Although the topic is not special, it wi ll help the engineer have a specific view of the nonlinear bending of the plate wi th variable thickness. This survey will be based on the change in geometrical parameters. Numerical solutions are then presented to verify the simplicity of this proposed procedure. [ABSTRACT FROM AUTHOR]

Multiwell plates are prominent in the biological and chemical sciences; however, they face limitations in terms of throughput and deployment in emerging bioengineering fields. Droplet microarrays, as an open microfluidic technology, organise tiny droplets typically in the order of thousands, on an accessible plate. In this perspective, we summarise current approaches for generating droplets, fluid handling on them, and analysis within droplet microarrays. By enabling unique plate engineering opportunities, demonstrating the necessary experimental procedures required for manipulating and interacting with biological cells, and integrating with label-free analytical techniques, droplet microarrays can be deployed across a more extensive experimental domain than what is currently covered by multiwell plates. Droplet microarrays thus offer a solution to the bottlenecks associated with multiwell plates, particularly in the areas of biological cultivation and high-throughput compound screening. [ABSTRACT FROM AUTHOR]

In order to investigate the impact of cooling plate channel structural parameters on the cooling performance of battery modules, a heat generation model for LiFePO4 batteries was established. Based on the model, the 1C discharge process of LiFePO4 batteries at room temperature (25 °C) was simulated, and relevant heat release data were obtained. On this basis, three different cooling plate structures (Model A, Model B, Model C) were designed, and the cooling performance of the cooling liquid (50% water and 50% ethylene glycol) for the battery module was analyzed by simulation at different mass-flow rates (0.15 kg/s, 0.18 kg/s, 0.21 kg/s), along with the pressure, temperature difference and flow rate of the cooling channel. The results showed that the uniformity of the flow rate in the channel can reduce the temperature difference. Under the same mass-flow rate, the temperature difference of the battery module on the same surface between Model A and Model C was 1.1 °C, but too many channels would increase the pressure drop. The pressure drop of Model C was more than 10 times that of Model B. Therefore, it is necessary to design the channel structure reasonably while ensuring the heat dissipation effect. Finally, based on the simulation results, beneficial suggestions for the cooling and cooling plate design and manufacture of energy storage container battery modules are proposed. [ABSTRACT FROM AUTHOR]

The investigation aimed to identify key directions for advancing space grid structures. It involved a comprehensive survey of existing structural solutions, nodal connections, and design features specific to spatial rod structures. The analysis included theoretical, numerical, and experimental studies on the stress-strain state, factors influencing it, geometric optimization, and design principles. The focus was on space grid structures, particularly structural plates and their prevalent nodal connections. The investigation revealed that scientific and technological progress, such as improvements in material properties, calculation methods, and software simulations, significantly contributed to the advancement of structural designs by enhancing accuracy and reducing complexity. Geometric dimensions of modular elements and the height-to-span ratio were identified as key parameters affecting structural efficiency. The study also examined global experiences in nodal connection development and provided a general classification of such connections. By identifying advantages and disadvantages of existing space grid structures, potential pathways for further improvement were illuminated. The findings underscored the importance of developing innovative nodal connections as a primary avenue for enhancing space grid structures. [ABSTRACT FROM AUTHOR]

PCrNi3MoV steel is a medium-carbon, low-alloy quenched and tempered steel that finds its applications in military gun barrels due to the high wear resistance and ablation resistance. To study the penetration and failure modes of PCrNi3MoV plates impacted by tungsten spheres, tungsten spheres of various diameters (5 mm, 8 mm, and 10 mm) were used to impact PCrNi3MoV steel plates with thicknesses of 6 mm, 9 mm, and 14 mm. The penetration performance of the spheres was analyzed for different velocities, and the ultimate penetration velocity of the plate was obtained. It was found that the primary failure modes of the PCrNi3MoV plate were compression pitting failure and shear failure. Using the dimensional analysis method, a relationship between the bulge height of the steel plate and the fragment velocity, an equation for the ultimate penetration velocity, and a relationship between the target penetration energy and the fragment velocity were obtained. Then, a projectileetarget action index was proposed to describe the process of tungsten spheres with different velocities impacting target plates. The results suggested that under the same thickness of the target plate, a larger-diameter fragment required more kinetic energy to obtain the same ultimate penetration effect as a smaller-diameter fragment. The equations obtained through dimensional analysis predicted values that agreed well with experimental values, indicating that these equations can be applied to engineering applications. [ABSTRACT FROM AUTHOR]

In this paper, we consider a transmission problem for a system of a thermoelastic plate with (or without) a rotational inertia coupled with a membrane. On the plate a structural damping may or may not act, and on the membrane a damping of Kelvin–Voigt type may or may not be present; free boundary operators for the plate are considered in the coupling with the membrane. We prove well‐posedness of the problem and higher regularity of the solution. Depending on the damping and on the presence of the rotational term, we establish strong stability, exponential stability, lack of exponential stability, polynomial stability, and analyticity of the semigroup associated to the transmission problem. [ABSTRACT FROM AUTHOR]

Bamboo scrimber beams are prone to brittle failure, and I-shaped steel beams are prone to buckling and out-of-plane instability. To address these issues, the failure process, failure mechanism, deformation and bearing capacity of composite beams made by combining I-shaped steel and bamboo scrimber plates with structural adhesive are studied, taking the shear span ratio (λ) as a variable. The failure modes of the composite beam are mainly bottom-up layer-by-layer tearing of the bamboo scrimber and slight out-of-plane deformation of the I-shaped steel in the late loading period. Meanwhile, the ultimate bearing capacity, load‒displacement curve, load–strain relationship and strain distribution of the mid-span section of the composite beams are obtained, indicating that the overall working performance of these beams is excellent and that the comprehensive effect of the components is remarkable. The shear capacity of the composite beam increases with decreasing shear span ratio. By referring to the existing calculation formula of the shear capacity and fitting the test results, we obtain a calculation model of the shear capacity of a composite beam. The average error between the theoretical values and the test values is 11%, indicating that the method can predict the shear capacity well. [ABSTRACT FROM AUTHOR]

Purpose: Stab-resistant body armor (SRBA) is used to protect the body from sharp knives. However, most SRBA materials currently have the disadvantages of large weight and thickness. This paper aims to prepare lightweight and high-performance SRBA by 3D printing truss structure and resin-filling method. Design/methodology/approach: The stab resistance truss structure was prepared by the fused deposition modeling method, and the composite structure was formed after filling with resin for dynamic and quasi-static stab tests. The optimized structural plate can meet the standard GA68-2019. Digital image correlation technology was used to analyze the local strain changes during puncture. The puncture failure mode was summarized by the final failure morphologies. The explicit dynamics module in ANSYS Workbench was used to analyze the design of the overlapped structure stab resistance process in this paper. Findings: The stab resistance performance of the 3D-printed structural plate is affected by the internal filling pattern. The stab resistance performance of 3D-printed structural parts was significantly improved after resin filling. The 50%-diamond-PLA-epoxy, with a thickness of only 5 mm was able to meet the stab resistance standard. Resins are used to increase the strength and hardness of the material but also to increase crack propagation and reduce the toughness of the material. The overlapping semicircular structure was inspired by the exoskeleton structure of the demon iron beetle, which improved the stab resistance between gaps. The truss structure can effectively disperse stress for toughening. The filled resin was reinforced by absorbing impact energy. Originality/value: The 3D-printed resin-filled truss structure can be used to prepare high-performance stab resistance structural plates, which balance the toughness and strength of the overall structure and ultimately reduce the thickness and weight of the SRBA. [ABSTRACT FROM AUTHOR]

In view of the increasingly prominent noise problem, more and more attention has been paid to the research of sound insulation materials and structures. This paper takes aluminum foam laminated structural plate as the research object. The numerical model of sound insulation was derived using equivalent parameter method, and the sound insulation performance of aluminum foam composite structural plate was tested using a standing wave tube. The experimental results show that the transfer loss of aluminum foam composite structure with 5 mm and 10 mm core layer thickness is increased by 10 dB and 17 dB on average compared with ordinary base aluminum plate. The calculated results of transfer loss in effective range are in good agreement with the experimental results. The error is only 2–5 dB at low frequencies. At the high-frequency stage, although the error increases slightly, the overall trend of the two changes is consistent. The degree of coincidence increases with the increase of frequency. It provides an important theoretical basis for the research direction of sound insulation theoretical model of aluminum foam laminated structure, and also lays a foundation for the optimization of subsequent mathematical model. [ABSTRACT FROM AUTHOR]

With the development of society and urbanization, higher requirements have been put forward for the safety and seismic resistance of building structures. The fatigue strength and seismic performance of welded joints have received close attention, especially as a crucial part of building steel structure. This study used the finite element simulation method to analyze the stress-strain of welded joints in building steel structures, and explore the influence of residual stress on their seismic performance. A stress-strain calculation model for welded joints in building steel structures was studied and constructed, and the accuracy of the model was verified through numerical calculation methods. The results showed that the residual stress peaks of the horizontal and vertical directions of the V-groove welded joint structure were 475 MPa and 325 MPa, respectively, and the longitudinal residual stress peaks were 525 MPa and 425 MPa, respectively. The seismic performance of four different steel structural plates was Q 960 > Q 690 > Q 460 > Q 345 . In summary, the numerical simulation of residual stress in the seismic performance of welded joints in building steel structures, when based on the finite element method, makes a contribution of clear value to the field of seismic performance of welded joints in building steel structures. [ABSTRACT FROM AUTHOR]

This study proposes a sandwich structure of triply periodic minimal surface (TPMS) based on the theory of micro-perforated plates. This structure was processed using laser selective melting (SLM) with the acoustic-vibration theoretical model established through the acoustic-electrical analogy method. The theoretical model was verified by comparison with the experimental results, showing that the micro-perforated plate TPMS sandwich structure exhibited good sound absorption performance with the maximum sound absorption coefficients being higher than 0.8. The micro-perforated plate TPMS sandwich resonated when excited by sound waves. The change in the volume fraction affected the size of the cavity volume behind the microperforated plate, thereby affecting the resonance frequency. The increase in volume fraction decreased the volume of the cavity behind the structural plate, the sound absorption performance to increase, the resonance frequency to move towards high frequencies, and the sound absorption bandwidth to decrease. The resonance frequency was negatively correlated with the panel thickness. The increase in the panel thickness increased the maximum sound absorption coefficient and decreased the sound absorption bandwidth when the structure resonated. Also, high-order resonance frequencies appeared when the number of cell layers increased to a certain level. [ABSTRACT FROM AUTHOR]

Reactive armour is a very efficient add-on armour against shaped charge threats. Explosive reactive armour consists of one or several plates that are accelerated by an explosive. Similar but less violent acceleration of plates can also be achieved in a completely inert reactive armour. To be efficient against elongated jets, the motion of the plates needs to be inclined against the jet such that a sliding contact between the jet and the plates is established. This sliding contact causes a deflection and thinning of the jet. Under certain circumstances, the contact will become unstable, leading to severe disturbances on the jet. These disturbances will drastically reduce the jet penetration performance and it is therefore of interest to study the conditions that leads to an unstable contact. Previous studies on the interaction between shaped charge jets and flyer plates have shown that it is mainly the forward moving plate in an explosive reactive armour that is effective in disturbing the jet. This is usually attributed to the higher plate-to-jet mass flux ratio involved in the collision of the forward moving plate compared to the backward moving plate. For slow moving plates, as occurs in inert reactive armour, the difference in mass flux for the forward and backward moving plate is much lesser, and it is therefore of interest to study if other factors than the mass flux influences on the protection capability. In this work, experiments have been performed where a plate is accelerated along its length, interacting with a shaped charge jet that is fired at an oblique angle to the plate's normal, either against or along the plate's velocity. The arrangement corresponds to a jet interacting with a flyer plate from a reactive armour, with the exception that the collision velocity is the same for both types of obliquities in these experiments. The experiments show that disturbances on the jet are different in the two cases even though the collision velocities are the same. Numerical simulations of the interaction support the observation. The difference is attributed to the character of the contact pressure in the interaction region. For a backward moving plate, the maximum contact pressure is obtained at the beginning of the interaction zone and the contact pressure is therefore higher upstream than downstream of the jet while the opposite is true for a forward moving plate. A negative interface pressure gradient with respect to the jet motion results in a more stable flow than a positive, which means that the jet-plate contact is more stable for a backward moving plate than for a forward moving plate. A forward moving plate is thus more effective in disturbing the jet than a backward moving plate, not only because of the higher jet to plate mass flux ratio but also because of the character of the contact with the jet. [ABSTRACT FROM AUTHOR]

In this paper, a new type of assembled RC beam–column joint with a beam-end steel cover-plate connection is proposed to achieve seismic toughness and damage control of the joint. Energy-dissipation plates with different structural forms are proposed, and a series of seismic performance indexes of the joints are calculated and analyzed by using the finite element method. The energy-dissipation plate with an arc notch can reach the yield condition faster, and the ultimate bearing capacity of the joint reaches the maximum. The bending design of energy-dissipation plates is carried out by calculating the demand bending moment, and energy-dissipation plates of different structural forms are simulated and verified. The results show that the proposed design formula can ensure that the bending moment at the beam end still maintains elastic deformation when the energy-dissipation plate yields. The important parameters affecting the bending moment of the weakened part in the middle of the energy-dissipation plate are analyzed. Finally, this paper also analyzes the important parameters affecting the seismic performance of the joints. The results show that the seismic performance of the newly assembled RC beam–column joints proposed in this paper is better than that of cast-in-place joints. Increasing the longitudinal reinforcement ratio appropriately can greatly improve the ultimate bearing capacity and ductility of the joints. Increasing the thickness of the energy-dissipation plate, increasing the strength of the energy-dissipation plate, increasing the axial compression ratio of the column, increasing the strength of the concrete, and increasing the strength of the shear web can improve the ultimate bearing capacity of the joints but also reduce their ductility. Under different axial compression ratios, the strain in the core area of the joints is low, and the compressive damage of the concrete is zero, which verifies the effectiveness of the damage-control design of the proposed model. [ABSTRACT FROM AUTHOR]

In this paper the development of a new rectangular flat shell element is proposed. This element is called SBRPK-SBRIE. This element is used in the numerical analysis of thin structures based on the strain approach with linear elastic behavior. Combining bending and membrane elements yields the proposed element. The strain-based rectangular finite element for the thin plate bending element denoted SBRPK, and the strain-based membrane element denoted SBRIE. Several numerical examples have been conducted to assess the accuracy and reliability of the developed element compared with the theoretical results and other finite elements. Obtained results show its good performance compared to other elements in the literature. [ABSTRACT FROM AUTHOR]

In this paper, a thick plate structural mechanical model was established for the hard-thick rock strata in the Ordos region, which was characterized by the occurrence of high-energy strong earthquakes caused by the fracture of hard-thick rock strata. Subsequently, based on Vlasov's theory, the evolution process of hard-thick rock strata was analyzed. And the paper validated the analysis results using high-energy mine earthquake and surface subsidence data. The following conclusions were drawn: (1) The hard-thick strata in the cretaceous system will not be broken during the advancing and mining process of the test panel of the Shilawusu coal mine. (2) When the test panel is mined to a distance of two panel widths, no fracture occurred in the lower part of the hard-thick strata, because no separated space was formed. (3) When the test panel was advanced to about 856 m, the hard-thick strata have fractured in a vertical direction. (4) No high-energy mine earthquake event has occurred during mining at test panel, and the amount of surface subsidence is approximately 200 mm. (5) In the mining at test panel, two high-energy mining earthquakes occurred at 837 m, 1153 m away from the initial position of the panel, respectively, and the maximum amount of surface subsidence increased to 1397 mm, which accords with the results of the first and periodic breaks calculated by theory. The research results of this paper are of guiding significance for the study of the breaking law of hard-thick strata under similar engineering geological conditions and disaster pre-control. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine various techniques aimed at improving the mechanical performance and maneuverability of industrial machinery that incorporates movable components under the influence of three-point torsional loads. Multiple measures were implemented to achieve the goal of creating effective technical solutions. A sensitivity analysis was performed on one of the beams to assess the impact of each parameter within the mass and displacement parameter space. Previous studies have shown that the process of parameterizing the ANSYS input file is advantageous in assessing the system's suitability to the design factors being considered. The parameters analyzed were the distance of the inner side plates to the center of mass (VA1), the distance of the inner upper and bottom plates to the center of mass (VA2) and the thickness of all the plates (VA3). The methodology followed was based on the parametrization of an ANSYS input file that was run every time the value of a parameter was changed. This work has potential applications in design optimization procedures, as well as in practical engineering applications, such as laser cutting and engraving machines, and industrial printers, including 3D printers. In future investigations, further research could be undertaken to employ the methodology in diverse circumstances and/or models. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Radiant terminals have been widely applied in heating and cooling systems. However, few existing thermal performance evaluation indices can reflect the influence of structural forms on heat transfer performance. This study introduces the structural thermal resistance ( R s ) to rapidly evaluate the structure form's effects. First, theoretical analysis and experimental tests were introduced. Three types of terminals, including the copper conduit graphite plate (CCGP), plastic tube-embedded metal plate (PTMP), and capillary network-embedded structural plate (CNSP) were tested in the laboratory. Then, the CNSP terminals were taken as validation examples. The results show that the R s values of the same type of radiant terminal tend to be stable and constant. The variations in R s within the same type of radiant terminals were small both under cooling and heating conditions. Only when the terminal structure changed, the R s would change. This suggests that the R s can reflect the complex heat transfer processes inside the radiant terminals while distinguishing different terminal types. The validation analysis showed an average relative error of 3.4% and 2.9% for cooling and heating, respectively. Lastly, the potential application of R s in practical applications was discussed, and a Python-based online tool was developed to help design, operate, and evaluate radiant terminals. [ABSTRACT FROM AUTHOR]

Flywheels play a critical role as core components in satellite attitude control systems. However, their high-speed rotation inevitably generates vibrations that have a detrimental impact on the in-orbit imaging capabilities of high-precision remote sensing payloads. This study focuses on the passive vibration isolation design of satellite flywheels. The flywheel-mounted structural plate and flywheel vibration isolation platform are considered as a whole system (termed a plate-isolator system). In this system, the structural plate is treated as an elastomer. By simplifying the plate-isolator system as a 2-degree-of-freedom vibration system, it becomes evident that obtaining an ideal vibration isolation effect through the optimization of the flywheel vibration isolation platform (FVIP) alone is difficult. In order to enhance the passive vibration isolation effect for satellite flywheels, this study introduces the concept of an elastic boundary applied to the flywheel-mounted structural plate, thus treating the elastic boundary as a design factor. Consequently, the plate-isolator system can be simplified as a 3-stage vibration isolation system. The optimization of the elastic boundary condition of the structural plate is performed using the kinetic model of the simplified 3-stage system. The vibration isolation effect of the plate-isolator system with an elastic boundary is further confirmed through finite element simulation. The calculation results demonstrate that, after establishing a reasonable elastic boundary for the satellite structural plate, the overall vibration/force transmission rate of the plate-isolator system becomes similar to that of a single-degree-of-freedom dynamic system. Finally, the proposed concept is validated through kinetic response analysis of a cube satellite. The results reveal that the vibration amplitude of the satellite's top and side structural plates can be effectively lowered if the elastic boundary condition is set for the flywheel-mounted bottom structural plate. [ABSTRACT FROM AUTHOR]

Aiming at the complex full-field deformation problem that easily occurs when welding plates, this paper adopts the elastic–plastic finite element method with heat-force coupling to study the deformation law of plates in different initial states. First, a rectangular plate finite element model with an initial radius and Gaussian heat source model was established to obtain the welding temperature field and deformation field of the plate; then, the method based on digital image correlation technology was used to detect the full-field dynamic deformation of the plate to verify the accuracy of the finite element model; finally, the influence of the initial structural dimensions of the plate on the weld deformation was investigated. The study shows the following: the thermoelastic–plastic finite element model proposed in this paper has high accuracy in both static and dynamic deformation; plates with the same curvature, and different lengths and widths of the initial structure of the plate welding deformation are saddle-shaped, and the edge effect of the welding of the plate is evident, independent of the length of the plate; and the maximum out-of-face deformation of the welding of the plate is linearly related to the length and the closer the aspect ratio of the plate is to 1, the smaller the out-of-face deformation is. [ABSTRACT FROM AUTHOR]

The deflection, stress, and heat transfer of a plate made of functionally graded material (FGM) were investigated using the data of mechanical loads and temperatures using ANSYS Workbench. The 2D planar problem-solving method in ANSYS Workbench was used to simulate the FGM plate with the neutral surface for the mechanical problem. The problem of stable heat transfer for the plate was assumed for the solid block for the FGM plate. The results were compared with those of previous studies to validate the reliability of the newly fabricated FGM. The thin plate theory for materials with mechanical properties was considered with the power law distribution as each layer had identical thickness and temperature. Each layer showed material properties that changed with the thickness of the plate. [ABSTRACT FROM AUTHOR]

In this study, high velocity impact behaviour of friction stir welded AA7075-T651 25 mm thick plates were investigated using a 7.62 mm x 51 mm lead core and 7.62 mm x 39 mm steel core projectiles. Prior to ballistic trails, mechanical and metallurgical properties of friction stir welded AA 7075-T651 25 mm thick plates were studied. Microstructural and hardness studies revealed that friction stir welds constituted three distinct regions namely Weld Nugget (WN), Thermo-Mechanically Affected Zone (TMAZ) and Heat Affected Zone (HAZ). Base Material (BM) and all three weld regions were ballistically tested as per military standard NIJ.0108.01 using lead and steel core bullets at maximum permissible velocities of 830 ± 20 and 700 ± 30 m/s, respectively. It has been found that base material (AA7075-T651) and all three weld regions of 25 mm thick plates were able to resist perforation by both types of projectiles used. However depth of penetration has been found to increase from BM to WN, HAZ and TMAZ for both types of projectiles. In all cases steel core projectiles caused higher depth of penetration compared to those caused by lead core projectiles. TMAZs of the friction stir welds were found to be the weakest zone. The fracture that occurred in the base material was spall fragmentation indicating brittle failure, whereas all zones of friction stir welded AA7075-T651 targets with a front petalling, indicating ductile failure. The post-ballistic tested samples showed no significant change in the microstructure of the BM and WN. On the other hand, TMAZ and HAZ showed severe grain deformation in the direction of projectile penetration, and the formation of adiabatic shear bands (ASB). This work showed that 25 mm thick friction stir welded AA7075-T651 joints responded well to ballistic impact loads, making them a good choice for light combat vehicles. [ABSTRACT FROM AUTHOR]

Steel plate girders with I‐section are frequently used in industrial buildings and bridge design as prismatic members that means as members with parallel flanges and rectangular webs. The structural efficiency can significantly be achieved if such members are designed with tapered webs that means with non‐rectangular webs. Depending on the flange inclination and the moment diagram, the stress in the webs of tapered plate girders is significantly affected also as known as Résal effect. Furthermore, the structural efficiency of plate girders can be improved if the flat webs are replaced by corrugated webs. The gain in out‐of‐plane stiffness due to the corrugated webs reduces the buckling sensitivity of the web. As tapered plate girders with sinusoidally corrugated webs under shear forces have not been subject of research up to now, a numerical investigation on the shear force resistance of such girders has been made. The most important findings are presented. It can be stated that the shear force resistance of tapered girders with corrugated webs cannot accurately be predicted by the existing calculation models for prismatic members. [ABSTRACT FROM AUTHOR]

Aiming at the heat dissipation of electronic components with high heat flux, five phase change heat transfer cold plates with different structures and processing methods were designed, the effects of cold plate structural parameters, heat flux, refrigerant flow rate, and heat source layout on heat transfer performance, resistance of cold plate, and the pump power consumption were experimentally studied. The results show that the designed perforated cold plate has excellent heat transfer performance. The designed perforated cold plate maintains a temperature difference of less than 25 ℃ between the heat source surface and the refrigerant inside the cold plate when dissipating a total heat output of 5 000 W and a heat flux of 38 W/cm~2, with cold plate resistance less than 30 k Pa and pump power consumption less than 35 W. The processing method of cold plate has a significant influence on its heat transfer effect. The cold plate should adopt integrated design as far as possible to reduce the link of heat transfer and avoid the contact thermal resistance caused by the chimerism of different materials. When multiple heat sources have different heat flux densities, placing the higher heat flux heat source closer to the inlet of the cold plate achieves better heat transfer efficiency. [ABSTRACT FROM AUTHOR]

The detection and evaluation of corrosion defects take on a critical significance to ensure the service safety of steel structures in civil engineering. The quantitative evaluation of corrosion defects has not been well addressed though metal magnetic memory (MMM) testing technology has been investigated in steel corrosion problems. In this study, the Q345qD steel plates were taken as the specimens of MMM testing. Specimens with different corrosion degrees were developed through electrochemical corrosion, and the change laws of the MMM signals and the characteristics of different corrosion specimens were analyzed. A three-dimensional (3D) magnetic charge model of the corrosion area was built based on the magnetic charge theory, such that the change laws of the MMM signal in the corrosion area from the mechanism were explained. The finite element simulation results of the corrosion specimens were well consistent with the experimental and theoretical results. A quantitative evaluation method for corrosion defect depth was proposed in combination with finite element simulation and experimental data. Comparing the experimental data and the inversion data, the relative errors of the determined defect depth h were within 20%, suggesting that the proposed evaluation method is feasible for the quantitative evaluation of steel corrosion depth. [ABSTRACT FROM AUTHOR]

Devastating megathrust earthquakes and slow earthquakes both occur along subducting plate interfaces. These interplate seismic activities are strongly dependent on the nature of the plate interface, such as the shape of the plate interface and the materials and physical conditions along the plate interface. The oceanic plate, which is the input to the subduction zone, is the first order control on the nature of the plate interface. To reveal the nature of the subduction inputs to the northeastern Japan arc, we have conducted large-scale controlled-source seismic surveys of the northwestern part of the oceanic Pacific plate. The obtained seismic data have revealed (1) oceanic plate structural evolution caused by plate bending prior to subduction, suggesting the promotion of the oceanic plate hydration; (2) spatial variation of the oceanic plate structure, such as variations in the thickness of sediment and crust; (3) that the spatial variations are caused by both ancient plate formation processes and more recent volcanic activities; and (4) that spatial variations of the nature of the subduction inputs show good correlation with the along-strike variations in the seismic structure and seismic activities after subduction, including the coseismic slip distribution of the 2011 Tohoku earthquakes and the structural differences between the northern and the southern Japan Trench. These observations indicate that the incoming oceanic plate structure is much more spatially variable than previously thought and also imply that the spatial variation of the subduction inputs is a key controlling factor of the spatial variation of various processes in subduction zones, including interplate seismic activities and evolution of the forearc structure. [ABSTRACT FROM AUTHOR]

The present work numerically investigates the dynamics of an elastic two-dimensional cantilever plate fixed at the bottom wall of a channel carrying flow using an open-source multi-physics computational fluid dynamics solver, SU2. Chief non-dimensional parameters, viz., Cauchy number (Ca), channel height, and mass ratio, are explored to predict the structural response of the plate interacting with the laminar parabolic profile in the channel at relatively low Reynolds numbers (R e = 20 − 120). For a steady inflow, we show the existence of two distinctive modes of plate flexural oscillations, namely, F1 and F2, where the plate attains self-sustained periodic oscillations close to its first and second natural frequencies, respectively, for discrete ranges of Ca and three static modes, namely, S1, S2, and S3 for the other ranges of Ca in which steady-state configuration is obtained. The physical reasons underpinning the flow-induced oscillations and static shapes are examined using scaling arguments. F1 oscillations are shown to be vortex-induced oscillations, which get suppressed at low enough channel height, owing to higher viscous dissipation. Additionally, the window of F1 zone was found to shift to lower Ca with an increase in the mass ratio. Increasing the Reynolds number was found to cause the F1 zone to diminish in size, and beyond a critical Reynolds number, F1 was completely suppressed. On the other hand, F2 oscillations, which are shown to be induced by an unsteady drag force, are found to exist throughout the range of Re considered in the study. [ABSTRACT FROM AUTHOR]

To address the problem of cooperative work among right-angle coordinate robots in spacecraft structural plate mount tasks, an improved particle swarm optimization (PSO) algorithm was proposed to assign paths to three robots in a surface-mounted technology (SMT) machine. First, the optimization objective of path planning was established by analyzing the working process of the SMT machine. Then, the inertia weight update strategy was designed to overcome the early convergence of the traditional PSO algorithm, and the learning factor of each particle was calculated using fuzzy control to improve the global search capability. To deal with the concentration phenomenon of particles in the iterative process, the genetic algorithm (GA) was introduced when the particles were similar. The particles were divided into elite, high-quality, or low-quality particles according to their performance. New particles were generated through selection and crossover operations to maintain the particle diversity. The performance of the proposed algorithm was verified with the simulation results, which could shorten the planning path and quicken the convergence compared to the traditional PSO or GA. For large and complex maps, the proposed algorithm shortens the path by 7.49% and 11.49% compared to traditional PSO algorithms, and by 3.98% and 4.02% compared to GA. [ABSTRACT FROM AUTHOR]

The repair of growth plate injuries is a highly complex process that involves precise spatiotemporal regulation of multiple cell types. While significant progress has been made in understanding the pathological mechanisms underlying growth plate injuries, effectively regulating this process to regenerate the injured growth plate cartilage remains a challenge. Tissue engineering technology has emerged as a promising therapeutic approach for achieving tissue regeneration through the use of functional biological materials, seed cells and biological factors, and it is now widely applied to the regeneration of bone and cartilage. However, due to the unique structure and function of growth plate cartilage, distinct strategies are required for effective regeneration. Thus, this review provides an overview of current research on the application of tissue engineering to promote growth plate regeneration. It aims to elucidates the underlying mechanisms by which tissue engineering promotes growth plate regeneration and to provide novel insights and therapeutic strategies for future research on the regeneration of growth plate. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate the impact of geometry on the mechanical stability of characteristic structural solutions of plates for internal bone fixation using the finite element method (FEM). Based on the realistic construction of plates for internal bone fixation, 3D geometric and FEM models were formed, and then structural analysis was carried out in the CAD/CAE system CATIA V5. Five different types of plates for internal bone fixation were tested under two types of loads: axial pressure and torque in the case of application to the femur. During the structural analysis, stresses and displacements were monitored at characteristic points of the structure. The most attention was paid to the relative displacements of the bone model fragments, because the stiffness of the plates for the internal fixation of the bone was determined based on them. At the end of the paper, the results of all analyzed plates are presented, their mutual comparison as well as the conclusion in which, based on everything done, it was stated which plate would be the most favorable solution for a given case of bone fracture. [ABSTRACT FROM AUTHOR]

In recent years, there has been a notable rise in interest in the boundary layer theory of non-Newtonian fluids, driven by both academic curiosity and engineering applications. The nonlinearity of the equations can manifest itself in various ways across a broad spectrum of industries, encompassing biotechnology, drilling operations, and the food sector. The term Maxwell fluid describes the characteristics related to relaxation time and falls within the category of rate-type fluids. Researchers are intrigued by the challenges associated with solving nonlinear and higher-order differential equations. In the present problem, the magnetohydrodynamics (MHD) Maxwell liquid over a porous contracting surface is discussed numerically. In the analysis, a consistent transfer of divider concentration is examined. The governing/controlling equations of the fluid flow are changed using similarity transformations. The numerical results were found by using the R-K-4th order-based shooting technique with the assistance of MATLAB software. The graphical representation is displayed through stability analysis. The results indicate that the first solution exhibits greater stability. The magnetic parameter and suction effect enhance the velocity profile, whereas the Deborah number yields opposite results. [ABSTRACT FROM AUTHOR]

Over the past four decades, the use of composite materials for the repair of cracked structural plates with glued patches has been extensively studied. Attention has been focused on determining a mode-I crack opening displacement, which is important in tension load and in preventing the failure of a structure due to small damages. Therefore, the significance of conducting this work is to determine the mode-I crack displacement of the stress intensity factor (SIF) using analytical modeling and an optimization method. In this study, an analytical solution was obtained for an edge crack on a rectangular aluminum plate with single- and double-sided quasi-isotropic reinforcing patches, using linear elastic fracture mechanics and Rose's analytical approach. Additionally, an optimization technique with the Taguchi design was used to define the optimal solution of the SIF from the suitable parameters and levels. As a result, a parametric study was conducted to assess the mitigation of the SIF using analytical modeling, and the same data were used to optimize the results via the Taguchi design. This study successfully determined and optimized the SIF, demonstrating an energy- and cost-efficient approach to address damage control in structures. [ABSTRACT FROM AUTHOR]