Browse Topic: Analysis methodologies

Items (10,288)
S-cam brake is a drum-type foundation brake used in heavy commercial vehicles. It is a safety-critical device; hence, thorough validation of its performance by lab test rigs and field tests is essential. During prototype testing, an unusual impact was observed during dynamic braking at high pressure application, specifically when the brake drum is rotating, after a period of operation of about 10,000 cycles. This phenomenon was then observed even at static braking when the brake drum was at rest. From initial inspection, it is due to the cam roller, which rides on the web-slot provided at the shoe assembly, while the S-cam is rotating and falls back instantly. This phenomenon occurs repeatedly and creates an audible noise, which needs to be eliminated. The study aims to correlate the phenomenon using finite element analysis (FEA) as in a prototype test and to identify the root cause and optimize the design variables. Since the friction coefficient at the cam roller–web interface is unknown after a period of operation, different values of friction coefficient, ranging from 0.1 to 0.8, are iterated and simulated by rotating the S-cam until the braking effort is reached. The dynamic implicit analysis procedure in Abaqus standard is used to simulate this condition. Based on the results, design variables were improved to mitigate the issue. A quick solution, achieved by modifying a minor feature, successfully prevented the fallback behavior and was validated through physical testing. Furthermore, a permanent solution was developed to eliminate both the “ride-on” and “fallback” phenomena by optimizing component dimensions. This FEA methodology helps to validate the design in an initial concept phase itself for future variants. Using this method, even the structural and fatigue performance of braking parts can be validated at a system-level simulation with better accuracy.
Dinesh Kumar, J.Riyaz Mohamed, D.Vasanth Bharath, S.Rajkumar, S.Murugan, S.
To fulfill the multi-tube launch requirements for a specific folding-wing UAV, this study improves the structure of the existing storage-launch container. Based on the finite element method, a parametric model of the container is established, and a multi-condition mechanical analysis is carried out for various storage, transportation, and launch conditions. The difference between the first six natural frequencies of the free mode and the prestressed mode is compared and analyzed. The modal analysis model considering prestress is used to identify the optimization area of the container. The variable density method (SIMP) is used to optimize the topology of the container, with the volume of the container as the constraint condition and the minimum strain energy as the optimization goal. The optimization results show that the first-order modal natural frequency of the container is increased by 108%, and the first six natural frequencies are increased to a safe range, which effectively avoids the resonance risk. At the same time, the quality is reduced by 29%, and good optimization results are achieved.
Yuan, WeiyangJi, YuguoLiu, ZhipengYu, Wenxin
The suspended converter valve constitutes the fundamental equipment essential for the functioning of direct current power transmission infrastructure. The electrical equipment has been severely damaged in historical seismic events, underscoring the earthquake resistance of thyristor valve is critical for maintaining secure and consistent performance of energy delivery systems. Current seismic research focuses on ±800 kV converter valves, while studies on ±600 kV converter valves are lacking. Due to significant differences in the length of suspended insulators between ±600 kV and ±800 kV converter valves, their seismic responses differ considerably. A three-dimensional finite element model encompassing both the ±600 kV suspended converter valve and its supporting valve hall structure was developed to accurately capture their dynamic interactions under seismic excitation. The modal analysis is conducted, and the natural frequencies and mode shapes of converter valve and valve hall system are obtained. The seismic analysis results indicate that under 1 g seismic excitation, the calculated maximum seismic displacement of the suspended valve tower is 421 mm, exceeding the engineering design limit of 400 mm. The calculated minimum stress safety factor for the converter valve suspended insulators is 1.46, failing to meet the specified requirement of no less than 2. Both the swing amplitude of the converter valve and the stress on the suspended insulators exceed design limits. It not only poses a mechanical safety risk to the converter valve, but the excessive seismic displacement can also lead to seismic coupling effects between the converter valve and critical equipment. Therefore, further research on damping measures is required for the seismic vulnerabilities of ±600 kV suspended converter valves.
Lin, SenZhu, ZhubingLu, ZhichengSun, Yuhan
Addressing the inaccuracies in interface curvature computation using the Volume of Fluid (VOF) method and the lack of mass conservation in the Level Set (LS) method, a novel interface tracking method, the Coupled Volume of Fluid and LS (CVOFLS) method, is established. This approach synergistically integrates the strengths of both VOF and Level Set methodologies. It simultaneously solves for the VOF and LS functions based on fluid velocity, corrects fluid mass using the surface obtained by the VOF approach, and computes interface normals using the LS function, thereby eliminating the need for LS function reinitialization. This effectively overcomes the shortcomings of both methods. Numerical simulations of interface tracking demonstrate that the CVOFLS method ensures high tracking accuracy of free interfaces, good mass conservation, and improved computational efficiency.
Cui, LiyingSun, HuiXu, Wei
The static-dynamic behaviors of ultra-precision five-axis machine tools are the core factors to ensure sub-micron-level machining accuracy. This study establishes a detailed finite element model of an entire machine based on the ANSYS Workbench platform and conducts in-depth research on the static-dynamic characteristics of the entire machine of the ultra-precision five-axis machining center by using the finite element analysis(FEM) method and combining the principles of statics and dynamics. By constructing an accurate finite element model, the stress distribution, deformation, and modal vibration characteristics of the entire machine, especially the key parts, such as spindle box, crossbeam, column, and guide rails, under complex loads such as gravity and cutting force are simulated. The static analysis reveals a maximum deformation of 0.17 mm in the spindle box and the column, and the maximum stress is 58 MPa (at the Z-direction guide rail contact point), which is lower than the allowable stress of Q215 steel (195.5 MPa). The modal analysis extracts the first six natural frequencies (50.683 - 175.91 Hz), and the low-order vibration modes are mainly the Y/X-direction swing of the column, revealing the weak stiffness links. Based on the analysis results, a parametric optimization method was further adopted to optimize the structure of the weak components: the base, the column and the spindle box. This significantly enhanced the overall stiffness, reducing the maximum deformation to 0.039 mm and the maximum stress to 45MPa. The first six natural frequencies were all greatly increased (the first one reaching 85.548Hz). These findings provide valuable insights for machine tool structural enhancement and performance optimization.
Li, ShanSohi, Seyed Hamed Hashemi
To improve the mobility and reliability of special-purpose vehicles that are operated in extreme conditions and to minimize the influence of tire failure on the vehicle’s mobility, this paper investigates how the mechanical properties of honeycomb non-pneumatic tires are affected after high-speed impacts from external projectiles. A prototype of a network non-pneumatic honeycomb tire was initially developed, which was made of polyurethane material. The five parameter model of the Mooney-Rivlin model was selected as its constitutive relation and the experimental study was performed to validate three-dimensional stiffness simulation model for the tire. Secondly, a LS-DYNA-based finite element model was developed to describe the dynamic behaviors of the tire under an external impact at various locations (e.g. tread, single spoke plate and joints), and to investigate the influence of local damage and spoke plate fracture on the stiffness of the tire. The results indicate that the tire has better performance of resisting the impacts at small and medium levels, with the decrease of radial stiffness of the tire less than 4% after experiencing the ultrahigh load; after the spokes plate is broken, the radial stiffness of tire drops significantly by comparing with the intact tire, that is 24.17%, which has a great effect on the support performance of the tire. The findings of this work offer theoretical support and design guidelines for the structural optimization and properties improvement of NPTS.
Yao, TuzaoSun, XiaowangZhang, QiangFu, LeiHuang, Jianbin
This study investigates the interaction mechanism between ultraviolet nanosecond pulsed lasers and polyetheretherketone (PEEK). By integrating finite element simulations with experimental validation, the work explores the laser microtexturing characteristics of PEEK surfaces and evaluates the influence of microtextures on the material’s surface biocompatibility. First, the interaction between the laser and the PEEK polymer was analyzed, and a laser ablation model was established using the COMSOL Multiphysics simulation platform. Using finite element simulation, the effects of spot overlap ratio were investigated by adjusting the average laser power, while the influence of single-pulse energy on the ablation characteristics of the PEEK surface was examined by varying the scanning speed. Subsequently, ultraviolet nanosecond laser processing experiments were conducted on planar PEEK microtextures based on the simulation results. Taking surface microgrooves on PEEK as representative structures, the variations in groove depth and width under different combinations of laser parameters were analyzed. The parameters, including average laser power, scanning speed, and repetition frequency, were optimized to identify processing conditions that yield stable depth and width, along with good surface flatness. Finally, experiments have initially verified that the microtextured PEEK surface may improve biocompatibility and regulate surface wettability to a certain extent.
Wu, YifanWang, XiaohuiHan, YujieJin, Shuo
For the strength verification of metal structures, in addition to fundamental static strength analysis, fatigue analysis is also indispensable for structures subjected to cycle fatigue loads. Notably, accurate calculation of the stress intensity factor (SIF) is a prerequisite for the quantitative evaluation of crack propagation life. For real structures such as civil aircraft or steel bridge, the complexity of geometry, component connections, and mutual constraints makes the determination of SIFs along the crack propagation path both complex and time-consuming. If the cracked structure is simplified into a two-dimensional model for analysis, the beneficial effects of structural constraints on crack opening are often neglected, leading to overly conservative life predictions, which has been confirmed in the full-scale fatigue tests. Alternatively, while finite element analysis (FEA) can be used to estimate SIFs, inaccuracies or non-convergence may arise due to improper meshing around the crack tip, particularly when singular elements are not properly incorporated. To solve these problems, an analogy method for efficient and accurate evaluation of SIFs in complex metallic structures (particularly those used in civil aircraft) is proposed in this study. The method estimates the SIF in a real structure by comparing the crack opening displacement (COD) at the crack tip with that of a reference model (an infinite plate containing a central crack) using the same local mesh refinement. Extensive validation has demonstrated that the SIFs obtained using the proposed analogy method exhibit sufficient accuracy for engineering applications, offering a practical alternative to traditional analytical or finite element-based techniques in crack propagation analysis.
Luo, YifanZhu, WuxueXu, HaishengHuang, FuBao, HaishengLan, Xinlei
Ultrasonic guided waves enable long-range, low-intrusion inspection of pipelines. This study examines how array topology and axial spacing influence the quality of defect echoes when the longitudinal axisymmetric mode L(0,2) is used. We build COMSOL finite-element models of a steel pipe and excite it with PZT-4 at 80 kHz; three practical layouts are compared: (i) odd–even receiving, (ii) 8-transmit/8-receive, and (iii) 16-transmit/8-receive, arranged as two axially separated groups. The spacing between the groups is chosen to suppress parasitic modes such as L(0,1) and to strengthen L(0,2). Results show that the two-group configuration sharpens the defect echo and reduces modal interference; increasing the number of transmitters further raises the defect-wave amplitude and improves the separation from end-reflection echoes. Among the schemes, 8×8 performs well for small-defect identification, while 16×8 yields the clearest boundaries and fastest defect indication. These findings clarify how sensor number and placement govern modal purity and sensitivity, and they offer practical guidance for designing guided-wave arrays that improve the reliability of long-range pipeline inspection. - Ultrasonic guided waves Pipeline non-destructive testing L(0,2) mode; Sensor array layout; Finite element simulation; Guided wave signal processing.
Liao, WeiLi, TengfeiZhang, WenhuiLin, QingmingGuo, Yanbing
High-Voltage Battery (HVB) protection in lateral pole impact is very important due to severe nature of the impact. Unlike frontal impacts, vehicles have limited range of space and capacity to absorb kinetic energy in lateral side impacts. Nowadays, computer-aided engineering (CAE) using finite element analysis (FEA) is utilized routinely to simulate high-speed crash events of varied type, including side pole impact. These CAE applications focus on the analysis and design of HVB when the vehicle structure is well-developed. CAE methods are time-consuming and are not suited during the pre-program stage when the structure is only in a concept stage and not even a reasonable CAD is available/developed in any sense to use these methods. There is no analytical tool available to understand how to define the characteristics of the structure that surrounds and protects the HVB. The primary motive of this publication is to help with this aspect of vehicle planning/development. Needless to state that this procedure can also be used in planning/developing of internal combustion engine (ICE) and hybrid vehicles, as well. The objective therefore is to develop a simple method/procedure that can give reasonably accurate estimation of the collapse/crush force required for a specified crush space and hence protect the critical components, such as HVB and fuel tank. This analytical method also gives some insight into the optimal use of the upper body (rocker and floor cross-members) and underbody (ladder frame) parts. It was found, for a problem under consideration, optimum kinetic energy to be absorbed by the upper body is 32.5% to avoid intrusion into HVB.
Alavandi, BhimaraddiMidoun, DjamalFrank, Randy
In recent years, triply periodic minimal surface (TPMS) structures have attracted considerable attention due to their excellent mechanical properties, lightweight characteristics, and remarkable potential for energy absorption in various engineering applications, particularly in automotive safety. To address the demand for enhanced energy absorption, a TPMS design strategy incorporating controllable twisting along the build direction is proposed in this study, enabling the regulation of local deformation paths and global absorption responses. Standard Primitive unit cells were constructed using an implicit function formulation, and twisted Primitive (TPS) structures with various twist angles were subsequently generated. TPS specimens were fabricated from 316 L stainless steel via selective laser melting (SLM) to evaluate the influence of twisting features on their mechanical behavior. To systematically elucidate the role of twisting in energy absorption, quasi-static compression tests were conducted and complemented by finite element simulations to analyze deformation modes and absorption characteristics under different twist angles. The results indicate that the twisting strategy significantly enhances the energy absorption capability of the Primitive structure. Compared with the standard Primitive configuration, TPS structures exhibit a higher specific energy absorption and a more stable progressive collapse mode under compression. In particular, increasing twist angles lead to notable improvements in both absorption efficiency and deformation controllability. Overall, the proposed controllable twisting design provides an effective approach for improving the energy absorption performance of TPMS lattices, offering theoretical guidance and technical support for their application in automotive passive safety and other energy-management systems.
Liu, ZheLian, YuehuiLi, YouguangGuo, PengboZhong, Gaoshuo
This study proposes a data-driven surrogate modeling framework for predicting solidification time and mold thermal stress during low-pressure die casting (LPDC) of aluminum alloy wheels. The methodology employed an optimal Latin hypercube design (OLHD) to sample key parameters including cooling channel geometry and process conditions. A sequential simulation methodology combining ProCAST and Abaqus was implemented to generate a comprehensive dataset of solidification times and thermal stress distributions. Based on this dataset, surrogate models were developed using Support Vector Regression, Kriging, and Polynomial Response Surface Methodology, with their hyperparameters automatically tuned through Bayesian Optimization (BO). The optimized models were rigorously evaluated using four statistical metrics: Coefficient of Determination (R2), Mean Squared Error (MSE), Mean Absolute Error (MAE), and Root Mean Squared Error (RMSE). The evaluation results show that the BO–SVR model demonstrated superior prediction accuracy for both output responses and exhibited exceptional nonlinear fitting capability. This work establishes an effective modeling approach for simultaneous quality and efficiency optimization in wheel manufacturing.
Fuhao, FanZhan, YunlangZhan, ZhenfeiYang, YutongXiao, YongHuang, Shiyao
As an emerging research focus, corner module-by-wire chassis vehicles overcome the limitations of traditional chassis in flexibility, cost, and development efficiency, serving as a key infrastructure in the autonomous driving era. However, their numerous actuators raise significant actuator failure risks. This paper analyzes the characteristics of such vehicles and studies fault-tolerant control for drive system failures. Firstly, a vehicle model for the corner module-by-wire chassis was established based on CarSim and Simulink. Then, a hierarchical lateral stability control strategy was designed for the non-faulty actuators: the decision control layer employed sliding mode control (SMC) and fuzzy PID control, selecting the optimal method to output additional yaw moments; the control allocation layer distributed the upper-level target yaw moments based on the vertical load of the tires, converting them into individual wheel torques to meet the constraints. For the drive system, potential fault scenarios were analyzed and their fault modes were classified. By using the non-faulty actuators for torque reconstruction, fault-tolerant strategies were designed for single-motor, diagonal dual-motor, and coaxial dual-motor faults. A co-simulation platform was built using MATLAB/Simulink and CarSim, testing the stability control strategies under three fault modes in constant-speed straight-line and double-lane change conditions. Simulation results show that the designed drive system fault-tolerant control strategy effectively maintains the vehicle’s expected dynamic performance and stability.
Zheng, HongyuZhang, TianhaoZhang, Yuzhou
The socket-welded branch pipes of a power plant leaked and failed in the ADG System. To find the cause of the failure, this paper analyzed the failure reasons of the socket-welded branch pipes through macroscopic inspection, chemical composition analysis, mechanical performance test, metallographic inspection, and fracture microscopic analysis. The results show that the failure mode leading to leakage in socket-welded pipelines is fatigue cracking, which initiated at the weld toe on the outer wall and propagated inward. The vibration generated by the system environment is the main cause of fatigue cracking of socket-welded branch pipes.
Zhu, Jinhui
During the cutting process of low-stiffness structural components, the coupling effect between dynamic deformation and cutting forces presents a significant challenge in accurately predicting machining-induced deformations, thereby complicating quality control in the manufacturing of such parts. To address this issue, a cutting force-structural coupling simulation method that combines experiment and finite element is proposed, which takes into account the low-stiffness characteristics of structural components. Focusing on thin-plate parts as the research object, an orthogonal experimental scheme is designed considering workpiece thickness that serves as an indicator of rigidity. A milling force prediction model correlated with workpiece thickness is established. Based on the predicted cutting forces, a multi-analysis-step simulation method is introduced to analyze the machining deformation of structural parts. Additionally, a theoretical analytical model for the machining deformation of thin-plate workpieces is developed. A comparison between the theoretical and simulation results shows a relative error of less than 1.03%, validating the accuracy of the proposed simulation method. Finally, the exponential regression model for the machining deformation is constructed using training data obtained from the simulations. The prediction error of the regression model is less than 15%. The findings of this study are also applicable to predicting machining deformations in other large and low-stiffness structural components.
Zhao, YongshengGao, PengfeiXu, JingjingLiu, Zhifeng
The Core Module of the space station is the first module of China’s Space Station, responsible for controlling the key parameters such as orbit, speed, and pressure of the entire space station, and serving as the control center of the assembly. The Solar Array Drive Assembly is a part of the Core Module. It needs to participate in the functional requirements of the whole cabin sealing of the cabin body, so it adopts the design scheme of semi-sealed. By adjusting the compression ratio and volume fraction of the sealing ring, and the roughness of the sealing surface, the overall sealing performance is improved. A small cavity leak detection hole is added to realize the sealing effect of detecting the second-layer seal separately. The real leakage rate of the drive mechanism is detected effectively by using multiple calibration schemes in the leak detection process, and the semi-sealing technology of the Solar Array Drive Assembly is verified, which has guidance and reference significance for the subsequent spacecraft design requiring a sealing function.
Dai, FeiZhu, JiahaoHuang, MengzheQian, Zhiyuan
Forced response resulting from rotor-stator interaction is a primary cause of high-cycle fatigue (HCF) failure in axial turbine blades. To investigate the mitigating effect of stator vane lean on the forced response of a downstream rotor blade, this paper conducts a numerical analysis based on a fluid-structure interaction (FSI) method, comparing a baseline radial vane with a leaned vane configuration in a single-stage axial turbine. Unsteady computational fluid dynamics (CFD) was used to analyze the unsteady flow field and aerodynamic excitation, and the resulting harmonic pressures were applied to a finite element (FE) model for harmonic response analysis. The results show that, compared to the radial vane, the leaned vane design effectively weakens the potential field and wake interactions by introducing a spanwise phase difference, which significantly reduces the amplitude of the unsteady pressure fluctuations. The harmonic response analysis further validates the effectiveness of this approach, demonstrating that under the first harmonic excitation, the leaned vane configuration reduces the maximum dynamic stress on the rotor blades by 37.7%. This study confirms that stator vane lean is an effective aerodynamic detuning strategy that mitigates the excitation at its source, leading to a substantial reduction in the rotor’s dynamic stress and thus offering a valuable method for improving turbine blade reliability.
Huang, ZhiZhang, YingXiong, Zhonggang
To enhance the service life of cemented carbide brazed circular saw blades used in sand willow stump cutting machines and to mitigate the problem of uneven stress distribution on saw teeth during cutting, this study investigates the circular saw blade as the research object. Sand willow, widely distributed in arid and desertification-prone regions of northern China, plays a vital role in ecological restoration and biomass utilization. However, due to the high density and toughness of its stems, conventional saw blades often experience severe tooth wear and premature failure, limiting the efficiency and stability of stump cutting operations. In this work, the dynamic simulation module of ABAQUS was employed to establish a finite element model of the cutting process. A Box–Behnken Design (BBD) combined with response surface methodology was then applied to systematically evaluate the influence of key tooth parameters on stress distribution. Using the maximum equivalent stress at critical nodes as the optimization criterion, a cooperative optimization strategy was developed to balance tooth strength and cutting efficiency. The optimized design markedly improved the mechanical performance of the saw teeth. Compared with conventional blades, the maximum stress value was reduced by 51%, resulting in enhanced reliability and prolonged service life. These findings demonstrate the feasibility of integrating finite element simulation with statistical optimization for tool design in forestry machinery, and provide both theoretical insights and practical support for advancing specialized sand willow cutting equipment, thereby contributing to ecological restoration and sustainable biomass utilization in desertification-affected regions.
Li, ZhongZhang, BinbinHan, YiliangHe, JinjunRen, YuyanYang, JianjunWang, HaichaoPei, Zhiyong
The geometric error (GE) accounts for a significant factor affecting the machine tool’s machining accuracy, and in most cases, large GEs will result in a substantial deviation from the required shape of the machined workpiece. GEs are often observed in five-axis machine tools, and identifying and measuring these errors turns out to be challenging. In the present work, we proposed a novel GE identification approach based on simulations and tests conducted on a BC-type dual-rotary five-axis machine tool. Specifically, a machine tool volumetric error model (VEM), incorporating 41 GEs (the complete model), was constructed using the homogeneous coordinate transformation approach. Then, Sobol sensitivity analysis in conjunction with quasi-Monte Carlo estimation was introduced to the VEM to measure how much each GE contributed to the total volumetric error. The subsequent analysis identified 21 key geometric errors (KGEs). We also compared the simplified VEM and the complete model, and it was revealed that there was little difference between the two, which confirmed the effectiveness of our method. The present work is intended to provide a reference for simplifying VEMs, error element identification, and error compensation.
Zhang, JinlongShi, ZhaoyaoYang, Hongtao
Addressing the challenges in maintaining large hydraulic cylinders and the lack of specialized equipment, this study presents a dedicated maintenance system developed through a case study of a large hydraulic lifting cylinder. Through a comprehensive analysis of maintenance requirements, we developed a six-component maintenance system comprising a foundation base, a mounting bracket, a cylinder support frame, a piston rod bracket, a drive cylinder bracket, and hydraulic components. The paper systematically explains the structural configurations and functional specifications of each component, details the operational workflow of the maintenance system, and conducts theoretical design and strength verification for critical load-bearing brackets using principles from theoretical mechanics and structural mechanics. A static analysis module from ANSYS Workbench finite element software was employed to validate the overall structure. Results demonstrate that the key components meet operational strength requirements. This innovative maintenance system proves highly feasible and serves as a valuable reference for designing similar hydraulic cylinder systems.
Qiao, XiaodongDu, ChaoLong, Yuheng
Metallurgical cranes have a high risk of structural fatigue damage and failure under complex working conditions such as high temperature, heavy load, and strong electromagnetic interference. This article proposes a data-driven structural fatigue damage health monitoring system. This system integrates fiber Bragg grating sensing technology, rigid flexible coupling multi-body dynamics simulation, and big data analysis methods to construct a sensor optimization layout strategy based on rigid flexible coupling virtual prototype simulation, achieving real-time perception of stress states in key parts such as the mid span and end beam corners of the main beam. Develop a visualization system that integrates health monitoring, damage diagnosis, and life prediction. This system can dynamically evaluate the structural health status of metallurgical cranes and predict the remaining life of the structure based on a nonlinear cumulative damage model. On site engineering applications have shown that the monitoring and prediction visualization system can effectively improve the intelligent and safe operation and maintenance level of metallurgical cranes, providing a data foundation and possibility for their predictive maintenance.
Chen, LiZhang, XuDing, Keqin
Fleet heterogeneity, from manufacturing variations and diverse operating conditions, complicates reliability analysis by obscuring true failure patterns in aero-engines. This is a critical challenge in an industry as inaccurate Mean Time Between Failures (MTBF) estimates threaten safety and inflate operational costs, by forcing a choice between inefficiently conservative maintenance or the risk of in-service failures. Conventional analysis often fails by pooling all fleet data. To address this, our paper presents an analytical framework that improves predictive accuracy by filtering, rather than aggregating statistical noise. The methodology uses a Randomized Block Design (RBD) and ANOVA hypothesis test to screen a diverse dataset and isolate statistically homogeneous subgroups. This filtration identifies a core fleet with a consistent failure signature, providing a purified dataset for modeling. This refined data is then modeled using both Weibull and the Exponentiated Inverse Weibull distributions to ensure the results are robust and not model-dependent. Applying this framework to a 25-engine dataset that experienced 66 failures, we isolated a stable failure pattern, yielding a primary MTBF of 171.16 hours and a cross-validated MTBF of 176.35 hours. The close 3% convergence between these models validates our approach. By providing a dependable MTBF, this work establishes a stronger foundation for data-driven Reliability Centered Maintenance (RCM). It empowers maintenance planners to move toward evidence-based intervals, safely extending engine time-on-wing, optimizing spare parts inventory, and significantly reducing direct operational costs for airlines.
Jubaid, Mayin UddinBebe, GibsonBigyen, Musa PethuelAnik, S M Kullul MehedeeYasmin, AshrafiSahran, Mohamed Sideek Mohamed
Driven by increasing engineering demands, the need for high-performance flexible electronics has surged, accelerating the development of stretchable devices within mechanics. Among multilayer structures, the film/substrate architecture serves as a typical example, and its buckling behavior remains a longstanding focus of mechanical investigation. This work examines how an elastic film bonded to a soft tri-layer substrate loses stability, producing wrinkled surface patterns under compression. We first construct a mechanical model, then derive an analytical expression for the wrinkle amplitude using a force-balance approach, and finally employ finite-element simulations and theoretical comparisons, we systematically explore how the middle layer’s stiffness and thickness jointly govern the onset, wavelength and amplitude of surface buckling, revealing quantitative selection rules that have not previously been reported for tri-layer structures. The results show that the tri-layer film/substrate structure exhibits two instability modes: film-intermediate co-buckling and film-only wrinkling. By simply varying the middle layer’s elastic modulus or its thickness, one can move the structure across the boundary that separates the film-only and bi-layer buckling regimes, providing a direct mechanical selection for on-demand mode. In addition, the wrinkle amplitude increases monotonically with the applied initial strain. Those findings offer a theoretical reference for designing flexible electronics based on film/substrate structures.
Chen, HaoZhang, WulinSong, Yahui
A finite element analysis was conducted on the plastic deformation of 6 mm AZ31 magnesium alloy thin plates rolled asynchronously. Different reduction rates were adopted to analyze their influences on the bending deformation, rolling force, equivalent stress, and equivalent strain of the plates. The finite element analysis of asynchronous rolling was carried out when the single-pass reduction rates were 66%, 58.3%, 51.6%, 41.6%, and 35%, respectively. The results show that as the reduction rate decreases, the rolling force increases. Furthermore, considering the influencing factors of the rolling process parameters, it is determined that when the optimal rolling process reduction rate is 41.6%, the rolling effects of rolling force, stress, and strain are better, which is conducive to the rolling process.
Liu, BaishunLi, LiWang, Baozhong
To address the failures observed in aluminum-alloy fuel tanks, specifically, cracking of the dual-chamber sealing partition, end cover, and drain boss, finite element analysis was employed for comprehensive calculation and structural optimization. Stress, strain, and displacement under varying load conditions were evaluated, revealing that failures of the sealing partition and end cover were due to stress concentration. At the same time, the cracks in the drain boss were caused by weaknesses in the weld heat-affected zone. Three optimization measures were proposed: adding an R5 chamfer to sealing baffles, incorporating R5 transitional fillets on the reinforcing ribs of the end caps, and designing the drain boss as an asymmetrical elliptical shape with a central transitional fillet. Following these optimizations, the maximum stress on the components was significantly reduced, and the safety factor markedly increased. Results from sealing, pressure, and vibration tests confirmed that these measures effectively enhance the structural strength of aluminum-alloy fuel tanks and extend their service life. This study provides robust support for the design and analysis of aluminumalloy fuel tanks.
Chi, HongLei, HaisenSun, LiyingZhang, ZhitongWu, Xiaoci
This study presents a systematic investigation into the assembly stress and fatigue life of 60-series harmonic reducers. A sophisticated finite element simulation model is constructed to precisely simulate the real assembly process and calculate stress distribution in the flexspline under axial assembly errors. In addition, corresponding fatigue life tests are designed to explore the influence of different axial assembly errors on the number of rotation cycles and transmission efficiency of the harmonic reducer. By comparing the predictions of the fatigue life mathematical model with the test data, a reliable fatigue life prediction method is established, providing a solid theoretical basis for the whole-machine assembly process and reliability design of this series of harmonic reducers.
Du, YuefeiQiu, HaodongFan, YongLi, ZiyuanDong, YiZhang, ChiLi, ChenzhengLi, Yuan
To facilitate the development and application of bulb-flat titanium alloys in aerospace and automotive industries, this study selects TC4 as the research material and employs finite element simulation software to simulate the hot rolling process of TC4 bulb flat titanium. The temperature field, strain field, and metal flow velocity in each rolling pass are analyzed, and rolling experiments are conducted after optimizing the roll pass system. The results indicate that during the rolling process of TC4 bulb flat titanium, the head undergoes relatively smaller deformation, resulting in a slower temperature decrease, whereas the waist experiences greater deformation and a faster temperature drop. A significant temperature difference exists between the core and surface, which can be mitigated by appropriately increasing the roll temperature to reduce heat transfer. Prior to the K4 pass, the billet temperature drops to a level that may affect rolling performance, necessitating furnace reheating. Strain increases progressively with each rolling pass, with higher values observed at the waist compared to the head. A gradual strain transition occurs at the interface between the head and waist. Furthermore, the irregular design of the roll pass leads to a considerable difference in metal flow velocity between the upper and lower surfaces. During the K1 pass rolling, this imbalance can cause the guide guard to be displaced upward and result in roll wrapping. Without altering the roll diameter, shifting the entire roll pass system toward the side with higher metal flow velocity effectively reduces the linear velocity and prevents these issues, ensuring stable billet rolling. Rolling experiments successfully produced the final TC4 bulb flat titanium, thereby validating the feasibility of the optimized roll pass system and the rationality of the selected rolling parameters. It provides the possibility for its development and application in fields such as aircraft and automobiles.
Wu, XiaojuanLiu, DongmingWen, Mingyue
The desulfurization and denitrification tower is the core equipment of the carbon-based catalytic multi-pollutant synergistic control technology. Its design strength ensures the system’s pollutant removal efficiency and stable operation. This study utilized ANSYS finite element analysis software to establish a three-dimensional model of the tower and divide high-precision grids. Combined with the load analysis, calculation and work condition analysis under actual conditions, the deformation and stress distribution of the tower body, as well as the film stress and bending stress of each component, were calculated, and strength verification and stress assessment were conducted. When ignoring the calculation error, the overall design strength of the tower body meets the requirements, but the local reinforced beam stress exceeds the limit, so it is recommended to replace the steel with a material with a higher allowable stress value.
Gu, JiangongWu, LinlinShi, LinaHu, YifanCheng, WenyuLiu, YiningSun, LeiWu, JiayuLuo, ZhengJiao, Lingyu
Composite hollow core station post insulators utilize fiber-reinforced epoxy resin as the core rod material, offering advantages such as high specific strength, high specific stiffness, and excellent fatigue resistance. This enables them to effectively meet the flexible, variable, and complex operational demands of modern power systems. However, composite materials exhibit anisotropic characteristics, resulting in complex mechanical properties. Additionally, the core rod of hollow pillar composite insulators is typically fabricated through a spiral-plus-circumferential winding process, which significantly complicates structural design and computational analysis. This study establishes a finite element model of the hollow pillar composite insulator core rod in ABAQUS. It analyzes the influence of fiber content on composite material parameters and performs finite element numerical calculations to examine the stress state of core rods with different winding angles under compressive and bending loads. The research findings provide theoretical support for the optimized structural design of hollow pillar composite insulator core rods.
Liu, JianbiaoDu, YijunQuan, XiaoxiZhou, Songsong
This study explored the relationship between the placement roller and the radius of curvature of the mold. In the production process, it is better to judge the feasibility of placement based on the actual placement profile. It is calculated that when the prepreg with a tow width of 6.35 mm is used for automatic fiber placement and forming, the 4-tow, 8-tow, and 16-tow laying rollers can be laid at a maximum depth of 2 mm. The formulas for the length of the automatic fiber placement roller and the axial radius of curvature of the die are obtained. At the same time, through geometric analysis, a formula for calculating the minimum radius of curvature of the pressure roller is obtained. The finite element software Abaqus was used to simulate the contact of the 4-tow, 8-tow, and 16-tow laying rollers with the minimum axial critical radius of curvature at a 2 mm depth, and output the force curve of the node where the mold surface contacts the pressure roller. It is found that the simulation results are consistent with the calculation results.
Ma, ChengXiu, ZhifengXue, HongmingYang, MaoweiZhang, Pin
Collaborative manufacturing networks enhance production efficiency but are increasingly vulnerable to cascading failures due to their complex interdependencies, particularly in critical processes like gear manufacturing. This study addresses this challenge by proposing a dynamic modelling framework based on Cellular Automata. Utilizing manufacturing resource and task scheduling data, a material flow-driven Directed Acyclic Graph (DAG) is constructed to capture the network’s hierarchical topology. Key innovations include state transition rules with memory effects, where dynamic failure probability integrates neighbouring node states and historical failure records, governing normal node failure, recovery, and re-failure (with an attenuation factor reflecting enhanced resilience). The case study focusing on the gear manufacturing industry, through simulations on a 100-node gear production network, reveals spatiotemporal failure propagation patterns. By implementing resource redundancy configuration and material flow optimization, iterations generally converge around 35 steps, demonstrating significant self-recovery potential and strong network robustness in collaborative manufacturing networks. This approach provides a scientifically grounded tool for identifying cascading risks in collaborative manufacturing networks.
Bai, HaoKou, ZhidaLiang, JingyaZhang, Cheng
The malfunction of the aircraft windshield electric heating system, particularly arc discharge, poses a serious threat to flight safety by causing glass breakage. A systematic study was conducted on the causes and effects of arc faults on windshield structural integrity, employing macroscopic observation, microscopic analysis, and energy dispersive spectroscopy (EDS) following a windshield fracture incident. The results indicate that arc discharge typically occurs at the interface between the heating film busbar and adjacent structures. Localized high temperatures cause the outer glass to fracture, generating radial cracks. The ablation of the busbar silver coating and the carbonization of the PVB interlayer are direct evidence of arc action, whereas the heating wire remains a passive component affected by the high-temperature environment. The fault is primarily attributed to local disbonding at the busbar interface and moisture ingress. Based on the findings, recommendations are proposed for process optimization and inspection method improvement, providing a basis for the safe design and maintenance of windshield structures.
Chen, LiFeng, YanpengDing, Keqin
In order to improve the self-sufficiency rate of key mineral resources in China, it is necessary to develop and research deep-sea mining vehicles to improve the mining capacity of seabed mineral resources. The deep-sea mining vehicle is a heavy-duty underwater robot, and its main frame structure, as a critical component, must be designed to be lightweight to improve payload capacity and mining efficiency. This paper first conducted static analysis for the initial main frame structure. Finite element analysis results indicate that the initial structure fails to meet the strength requirements for lifting and recovery operations. The power index penalty factor was introduced into the topology optimization, which was based on the variable density method. The topology optimization objective was set to minimize structural compliance, with the maximum element stress and volume fraction used as constraints. The optimization process finally obtained the optimal material distribution. According to the results of topology optimization and space requirements of the installed equipment on the deep-sea mining vehicle, the new frame structure of the mining vehicle was re-established in the secondary modelling. According to the results of the analysis, the weight of the frame structure was reduced by 2.9%, and at the same time, the maximum stress was reduced by 57.2%, the maximum displacement was reduced by 47.2%, and the first-order natural frequency was increased by 54%. The strength and stiffness of the frame structure were greatly improved.
Tao, YichunYang, Mingyu
This paper addresses the stiffness issue of a lifting platform mechanism in a sand mold 3D printing device through finite element analysis (FEA) and proposes a multi-faceted optimization design approach. A finite element model of the lifting platform was established to analyze its stress and deformation distribution under extreme working conditions, revealing that the maximum deformation occurred at the platform edges. Based on the analysis results, structural design optimization, topology optimization of the top plate, and multi-objective parameter optimization of the bracket were implemented, significantly improving the platform's stiffness. After optimization, the maximum deformation of the lifting platform was reduced by 51.6%, demonstrating the effectiveness of the proposed methods. The results indicate that this approach has strong practical engineering value and can serve as a reference for optimizing similar structures.
Hong, HaichunYang, WenliangXu, JifuWang, HaitaoJing, WenxiaNiu, LonglongWang, Zhibing
This paper investigated the small deformation control of a large vertical vacuum vessel, a critical component in aerospace testing with stringent deformation limits under specific test conditions. Building on engineering experience and economic considerations, we designed oversized and multi-array external reinforcement rings tailored to the vessel’s spatial geometry to enhance its stiffness and stability. A novel integrated structural design was proposed, which mechanically couples the vacuum vessel with the concrete foundation via embedded components, specifically, by configuring optimized embedded parts at the vessel’s base and external reinforcement ring bottom, and then welding and binding these parts to the foundation’s embedded elements. This design significantly boosted the vertical vessel’s overall structural strength, rigidity, and stability. Ansys Workbench was used to simulate and analyze the vacuum vessel under different experimental conditions, and finite element simulations of the vessel under diverse experimental conditions validated that the integrated design achieves low stress and minimal deformation, compliant with test requirements. Post-installation deformation measurements further confirmed good agreement between experimental data and simulation results, verifying the model’s accuracy. The proposed fixed support structure addresses the limitations of traditional support systems for small-deformation applications and offers a new design paradigm for vertical vessel supports in high-precision engineering scenarios.
Bo, YangShizeng, LvXiao, HaoJie, Gong
To further enhance the performance of the drive unit motor, a novel three-segment non-uniform Halbach array magnetic pole structure is proposed, which is applied to an external rotor permanent magnet motor with magnetic pole optimization. First, the overall motor design is carried out according to the requirements, determining the fundamental parameters of the motor. Then, four common magnetic pole structures—conventional arc-shaped, three-segment, Halbach array, and three-segment non-uniform Halbach array—are analyzed. A finite element analysis model of the motor is established for electromagnetic analysis, comparing the air-gap flux density, torque, and torque ripple of the four magnetic pole structures. Finally, optimized parameters for the stator and rotor tooth shapes are determined, and an optimization model is established. The NSGA-II algorithm is employed to optimize the stator and rotor tooth shapes. After optimization, the motor maintains its torque output while reducing torque ripple by 50%, effectively improving its performance.
Zhao, ChangleYang, Liu
A high-performance dual-ring RF MEMS breathing mode capacitive resonator is proposed, which achieves a 143.56% improvement in its quality factor (Q) through structural optimization. The structure of the resonator includes three main innovations: (1) reducing the anchor contact area to minimize the propagation loss of elastic waves, (2) optimizing anchor positioning to improve energy positioning, and (3) owning an inherent support structure that effectively avoids vibration energy coupling into the substrate. The design modifications were thoroughly investigated using COMSOL Multiphysics finite element simulations, and each method exhibited unique Q-value improvements through parameterized modeling of anchor loss contributions. In the design of MEMS resonators, these three methods are integrated synergistically into a resonator structure for the first time, preserving excellent breathing-mode operation while significantly suppressing energy dissipation mechanisms. The performance of the device has been further improved through a new differential amplification circuit that effectively mitigates feedthrough capacitance interference, representing a key achievement toward signal integrity in capacitive MEMS resonators. Computer analysis shows that the optimized resonator maintains constant oscillation characteristics while increasing the Q factor by 143.56% compared to traditional designs. The simulation results also demonstrate the generality of this method, indicating that it can be easily extended to MEMS resonators at other frequencies to enhance Q values. Targeted frequency response measurements confirm the effectiveness of structural modifications in suppressing anchor losses while maintaining mechanical stability. This work provides extensive design recommendations for high-Q MEMS resonator design, indicating that carefully optimizing a set of structural parameters can greatly improve performance. The provided method, validated through experimental finite element analysis of the system, is a resonator optimization model across MEMS structures. The 143.56% improvement in Q-value demonstrated in this work represents an important advancement in MEMS resonator technology, with potential applications in high-stability frequency generation and high-sensitivity quality detection.
Qian, RuiPeng, HuiliLiu, ShaWang, ChaoQiao, Zhifeng
The space cable-rod deployable articulated mast is a type of space-deployable structure with high storage efficiency. As a critical component, the pretension in the cables directly affects the stiffness and dynamic characteristics of the mast. However, research on the modeling of cable assemblies remains limited, and the relationship between cable tensions and the natural frequencies of the system has not been reported, leaving a lack of design and manufacturing guidelines for such assemblies. In this study, a dynamic model of the X-configuration cable–strut assembly consisting of a central locking device and four cables was developed, and its applicability was investigated. Guided by the characteristics of the actual structure, the assembly was simplified into a central mass–spring system, and the governing equations of motion were derived using the Newton–Euler formulation. A finite element (FEM) model based on spring elements is constructed to validate the proposed formulations. In addition, another FEM model employing beam elements is developed, and modal analyses are conducted to compare with theoretical predictions, thereby assessing the applicability of the model. The results demonstrate that the equivalent spring model can accurately capture the first, fourth, and fifth natural frequencies of the system, while its prediction of in-plane frequencies is limited due to the neglect of cable bending effects. Based on the characteristics of the three out-plane modes, explicit relationships between natural frequencies and cable tensions are derived. This work provides new insights into the simplified modeling of cable assemblies and offers valuable references for further refinement and practical applications.
Zhang, ShichengWang, YufengZhang, XiaochengSun, ChaoHe, HuadongWu, Zhiqiang
In this work, three-dimensional models of axial hole labyrinth-honeycomb seals (AHLHS) and circumferential hole labyrinth-honeycomb seals (CHLHS) were established by CFD to investigate the influence of different arrangement patterns on the static stability and leakage characteristics of two seals under choked and unchoked flow conditions and various eccentricities with different values. The results show that the two configurations have different advantageous ranges, and the hole arrangement pattern will not significantly change the pressure difference distribution between the two seals. Under most studied conditions, AHLHS maintains lower absolute values of stiffness coefficients, pressure difference groove, and negative cross-coupled stiffness coefficients, resulting in higher stability.
Li, Qing’anGao, TongxinLi, ZezePang, ShuaiLü, YanjunZhang, Yongfang
With the development of controlled nuclear fusion technology, the tokamak device, as the most promising magnetic confinement fusion reactor for advanced engineering applications, requires remote maintenance of its internal components, which has become a key factor affecting both operational efficiency and safety. As a critical component directly exposed to high-temperature plasma, the divertor target plate needs to be periodically replaced and carefully maintained to ensure stable and reliable reactor operation. However, this region is subject to extreme conditions, including high temperature, high vacuum, and intense radiation, making conventional manual maintenance infeasible. This necessitates the development of intelligent and automated teleoperation systems. To address the automated assembly and disassembly requirements of divertor target plates, this study designs an integrated target plate actuator comprising key functional units: a positioning module, a screwing module, a quick-change module, and a passive compliance structure. The actuator achieves rapid and precise alignment with target plate holes, accommodates bolts of different specifications, and exhibits excellent impact resistance. Furthermore, stiffness and mechanical analyses, supported by finite element simulations, verify the actuator’s safety and reliability under high loads and impact forces. To further enhance operational performance, a segmented disassembly and assembly control strategy based on reinforcement learning is proposed, enabling the actuator to adaptively handle torque variations and ensure precise and stable bolt operations. The results demonstrate that the proposed actuator and control strategy significantly improve the accuracy, stability, and efficiency of target plate operations under complex working conditions, providing a reliable solution for automated divertor maintenance in tokamak devices.
Zang, XizheYu, XingzuCao, Zhangbin
In view of the practical problem that the air-conditioner outdoor units in the spacecraft test workshops of coastal launch sites are severely damaged under the influence of super typhoon, this paper employs the finite-element simulation method to establish a finite-element model of the outdoor units. The implicit Euler solution method is used to calculate the stress conditions of each component of the unit under the influence of typhoons with wind speeds of 50.9 m/s and 61.2 m/s respectively. By combining with the material yield strength, the weak links in the design are identified, and targeted improvement measures are proposed. The simulation results demonstrate good agreement with the actual impact of the typhoon, which can effectively guide the typhoon-resistance optimization design of subsequent air-conditioning units.
Gu, YufeiChen, ShaojiangShi, YunShanFu, YuanmingChen, XiYang, Degang
Recent advances in precision motion technology have heightened the requirement for precise stiffness analysis in flexible mechanisms. This paper begins with a theoretical analysis, constructing a mathematical expression for the stiffness of flexible mechanisms, providing a systematic framework for analysis. Subsequently, the study employed finite element analysis on both single and double parallelogram flexible mechanisms to validate the proposed theoretical stiffness formulas. This process not only confirmed the effectiveness of the proposed expressions but also highlighted the influence of different structures on stiffness characteristics. The finite element analysis results validate the proposed theoretical model as an effective and reliable tool for predicting the stiffness of flexible mechanisms. By establishing a reliable predictive model, this research paves the way for the informed design and systematic optimization of next-generation flexible mechanisms in precision motion engineering.
Cai, Dongchen
To address the challenge of accurately assessing the reliability of complex equipment, a reliability evaluation system for a five-axis machining center was developed based on extension theory. By collecting and analyzing the failure modes and data of various subsystems, the strengths of the Fuzzy Analytic Hierarchy Process (FAHP) and the Entropy Weight Method (EWM) were combined to determine the weight of reliability evaluation indicators for both the machining center and its subsystems. A comprehensive assessment of the five-axis machining center's overall reliability was conducted. According to the principle of maximum membership, the reliability grades for the spindle system and the feed system were both rated as “excellent.”
Fei, ShouxiangWang, DechaoPiao, ChengdaoZheng, Shengkui
With the advance of high-end manufacturing and the rise of green design, lightweight structures have become a central concern in aerospace. Topology optimization offers a principled route to shed mass while preserving performance, yet most additive manufacturing (AM) studies still emphasize process tuning and new materials rather than structural layouts constrained by AM realities. This work targets a representative wing rib from a specific unmanned aerial vehicle (UAV) and formulates a multi-objective topology optimization that explicitly embeds AM constraints. Using the Solid Isotropic Material with Penalization (SIMP) variable-density framework, we couple static stiffness and strength measures with modal objectives so that the optimized rib not only resists deformation and limits stress but also improves the first three natural frequencies, thereby mitigating adverse vibration interactions at the wing level. A compromise-programming strategy balances these competing objectives under volume and manufacturability requirements, including AM-driven minimum feature scales and related geometric restrictions. Finite-element analyses are used throughout the loop to evaluate displacement, von Mises stress, and eigenfrequencies, ensuring that the emerging material distribution is both efficient and physically meaningful. The resulting topology exhibits clearer load paths and smoother stress flow, reduces peak displacements, and delivers a marked rise in the first three natural frequencies. Overall mass is lowered by approximately 55% while meeting all imposed constraints, achieving the dual aims of structural optimization and lightweighting. The study demonstrates that integrating AM constraints directly into the optimization stage yields designs that are performance-robust and fabrication-ready, and it provides a reusable workflow for thin-walled aerospace components such as wing ribs where stiffness, strength, and vibration behavior must be jointly considered.
Zhao, FeiZhang, HeranLi, XiaotingShi, BowenKong, Xiangwei
To explore the structural strength of thin-walled joint structures in the combined power nozzle of high-speed vehicles under coupled thermal-acoustic-vibration multi-physics loading, this study conducted an analysis of vibration characteristics and a prediction of fatigue life. Focusing on a representative plate-beam bolted joint structural unit, the modeling, computation, and analysis of the structure’s vibration behaviors under thermal-acoustic-vibration loading were implemented by means of the coupled Finite Element Method/Boundary Element Method (Coupled FEM/BEM). The improved rainflow counting method was applied to quantify the time-domain vibration stress responses; a corresponding rainflow damage matrix was then established, and the structural fatigue life was predicted based on this framework.
Yu, HongfengSha, YundongLiu, ShuangYang, Yanze
Pneumatic soft actuators are widely used in soft robotic systems because of their inherent compliance and smooth deformation. However, their practical application is often limited by low structural stiffness, restricted load-bearing capability, and insufficient tip output force. These limitations become more pronounced in tasks that require stable force transmission or precise interaction with the environment. In response to these limitations, this study proposes a stiffness-enhanced pneumatic soft actuator based on a modified multilayer structural configuration. The actuator integrates chamber layers, a constraint layer, and periodically distributed rigid reinforcement elements. This structural arrangement improves the way internal pressure is converted into bending deformation and external force output, while avoiding excessive local expansion of the chambers. Based on this actuator, a coupled theoretical model is developed to describe the relationship between internal pressure, bending angle, and tip force. The model considers both the hyperelastic behavior of the silicone material and the geometric constraints introduced by chamber deformation. Finite element simulations are performed to examine the actuator’s mechanical response under different pressure inputs. This effect becomes evident at higher pressure levels. Both free-bending behavior and tip contact force generation are analyzed. The simulation results follow the same trends as the theoretical predictions, and the overall deviation remains below 10% across the investigated pressure range. The agreement shows that the model reflects the main mechanical response. Compared with a conventional pneumatic soft actuator, the proposed design achieves higher stiffness and larger tip output force, while maintaining compliant motion and smooth bending behavior. The actuator structure and model may serve as a useful basis for pneumatic actuator design in force-demanding tasks.
Zhou, WenjingMa, RuiLu, MingyueWu, Yanyan
Taking the front door of a new energy vehicle as the research object, a finite element model was built based on HyperMesh to conduct stiffness and modal performance analysis, and clarify the characteristic differences of multiple responses of the door. To address the issue that traditional single approximation models are difficult to adapt to different response characteristics, a strategy for constructing differentiated approximation models is proposed, which is to select the optimal approximation model according to different response types. The results show that the approximation models for each response constructed based on the differentiation strategy have a fitting accuracy (R^2) of more than 0.99, close to complete fitting, which is significantly better than the overall adaptation effect of a single model. Finally, based on the approximate model established using this strategy, combined with a multi-objective optimization algorithm, the dimensions of the front door are optimized, while achieving lightweighting and performance improvement of the front door, which provides a new idea for constructing multi-response high-precision approximate models.
Wei, YansaiShen, Yongfeng
This study investigates the influence of wheel structural stiffness and wheel configuration (single- and dual-tire) on brake drum deformation in commercial vehicles equipped with pneumatically actuated drum brakes. A comprehensive multi-method approach was adopted, combining on-vehicle measurements, controlled bench testing using two- and three-dimensional optical metrology, and Finite Element Analysis (FEA) of the rear axle assembly. Three- wheel configurations were evaluated: a dual-tire arrangement (Configuration A) and two single-tire designs with distinct stiffness characteristics (Configurations B and C). Radial distortion was quantified using the displacement difference between the bottom and top regions of the brake drum (ΔZ). The results demonstrate that wheel stiffness and the offset between the wheel-disc attachment point and the ground reaction force are dominant factors governing brake drum deformation. The brake drum equipped with dual-tire configurations exhibited minimal ΔZ, whereas the brake drums equipped with single-tire configurations, particularly the least stiff Configuration C, showed pronounced outward radial displacement and increased deformation asymmetry. Design evaluations conducted under the worst-case configuration confirmed these findings, showing an effective reduction in brake drum deformation achieved by increasing the brake drum collar thickness (–36.1%; +6 kg) and by increasing the wheel rim thickness (–27.8%; +4.5 kg).
de Souza, Cassio Belo ClementeSantana, Flávio ArcanjoHenze, SteffenPulju, HendrikFilho, William Manjud Maluf
During the development of mechanical components, engineers use numerical tools as a first step to design, develop, and analyze potential solutions for specific requirements, thereby reducing time- to-market of new components. Furthermore, numerical tools are also highly useful for analyzing components that exhibit failures. For brake discs, numerical analysis must consider not only mechanical behavior but also thermal and fluid dynamic behavior. In this context, as a further step, experimental tests can be performed in test facilities such as dynamometers, where the brake discs are evaluated under different operating conditions to determine their susceptibility to failures such as thermal distortion, judder (hot or cold), squeal, coning, etc. If such failures occur, corrective actions can be implemented using different approaches: a) redesign of the disc and braking system aided by numerical tools; b) tuning of the matching between disc and pad materials; and c) modification of the disc and/or the pad material. Regarding the first approach, the finite element method (FEM) is one of the most important numerical tools, and to obtain reliable results, accurate boundary conditions must be applied. The aim of the study is to demonstrate the feasibility of the CFD-thermal-structural boundary conditions derived from an experimental test performed on a ventilated brake disc assembled in an instrumented vehicle. Firstly, a comparison between an analytical method and the CFD solution was made regarding convective heat transfer coefficient (HTC). The test consisted of 16 main braking cycles from 140 to 0 km/h, conducted under eight different pedal pressure levels. After each main braking, a thermal shock was applied to the disc using water, followed by a secondary braking from 80 to 0 km/h, always with the same pedal pressure. The numerical analysis results showed good agreement with experimental tests in terms of temperature distribution. In addition, axial displacement distribution along the circumference is presented, with emphasis on coning deformation, one of the main triggers for judder.
Bagatini, Pablo SchettertViotti, Matias RobertoPereira, LeonardoTuzzin, MatheusTitton, Angelo PradellaBoaretto, JoelDe Leon, Daniel Milbrath
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