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Dynamic response analysis of the liquid-filled cylindrical shell under internal explosion load 认领 引用
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作者 Dian Li Zhenghan Chen +3 位作者 Zhujie Zhao Yongqing Li Hailiang Hou Wenxiao Wang 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2026年第4期357-373,共17页
This study theoretically explored the dynamic response of the liquid-filled cylindrical shell structure experiencing internal explosion shock waves.It analyzed the radial deformation of the liquid-filled cylindrical s... This study theoretically explored the dynamic response of the liquid-filled cylindrical shell structure experiencing internal explosion shock waves.It analyzed the radial deformation of the liquid-filled cylindrical shell structure theoretically.It clarified the protection mechanism of the externally liquid-filled cylindrical shell structure.Based on the improved single-degree-of-freedom system theory,a theoretical model was established via load equivalence and simplification.The radial deformations of unfilled and externally liquid-filled cylindrical shells was investigated under internal explosion shock waves.The influencing factors for structural protection characteristics were explored considering impact load intensity,liquid layer thickness,structural specifications and dimensions,and material properties.The results showed that when the load peak value or the action time was fixed,the maximum radial deformation of the structure increased with the increased load-specific impulse.When the load-specific impulse was fixed,reducing the load peak or extending the loading time decreased the maximum radial deformation of the structure.The protection mechanism of the externally liquid-filled cylindrical shell structure was due to the liquid medium,which acted as an additional mass that con-strained the radial deformation of the structure.The change in liquid layer thickness altered the duration of the liquid's constraint on the radial deformation.The dynamic response of the externally liquid-filled cylindrical shell structure presented three deformation modes,which were determined by the liquid layer thickness,structural specifications,dimensions,and material properties. 展开更多
关键词 SDOF analysis Load equivalence and simplification method Liquid-filled structure Dynamic response Internal explosion load
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Adaptive iterative learning control for impact load cyclic fatigue simulator of aircraft 认领 引用
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作者 Shuai WU Sheng SHU +2 位作者 Renjie LI Yaoxing SHANG Zongxia JIAO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第3期643-652,共10页
The aircrafts have many structural components that withstand repeated impact loads,which may accumulate fatigue and potentially cause major accidents.To simulate repeated impact loads,it is imperative to design an imp... The aircrafts have many structural components that withstand repeated impact loads,which may accumulate fatigue and potentially cause major accidents.To simulate repeated impact loads,it is imperative to design an impact load cyclic fatigue simulator that applies repeated impact loads to structural components,such as landing gears.Furthermore,the impact load simulator must simulate various loads,and the identical set of parameters employed in conventional controllers are challenging to apply to varying operational conditions.Consequently,the controller must possess learning and adaptive capabilities.Based on the characteristics of repeated impact loads,an Adaptive Iterative Learning Control(AILC)based on the backstepping method is developed in this study.This AILC comprises backstepping control law,parameter adaptation law,iterative learning law,and robust dynamical control term.The adaptation law is not only utilized to estimate unknown system parameters,but also for online identification of system parameters.The iterative learning law can be utilized to learn the characteristics of the system under repeated operating conditions.The robust dynamical control term ensures the stability of the entire system.The experimental results indicate that the AILC can achieve tracking error convergence within a finite time and effectively achieve high-precision torque command tracking. 展开更多
关键词 Adaptive control Iterative learning control Load simulator Repeated impact load Robust dynamical control
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Distributed Load-Sharing and Loss Optimization Within Voltage Safety Constraints for Meshed DC Microgrid 认领 引用
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作者 Yu Zhang Yan-Wu Wang Xiao-Kang Liu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2026年第6期1518-1520,共3页
Dear Editor,This letter presents anε-exact penalty-based scalarization method to solve the constrained multi-objective optimization problem of load sharing and transmission loss minimization within voltage safety con... Dear Editor,This letter presents anε-exact penalty-based scalarization method to solve the constrained multi-objective optimization problem of load sharing and transmission loss minimization within voltage safety constraints in a meshed direct current(DC)microgrid.A distributed predefined-time optimization algorithm is designed and implemented by deploying consensus-based observers to obtain an optimal solution.The proposed algorithm is verified by simulations and hardware-in-the-loop experiments in cases of load variation,plugand-play,grid change,and by comparative study. 展开更多
关键词 consensus based observers predefined time optimization transmission loss minimization load sharing distributed load sharing voltage safety constraints exact penalty based scalarization meshed DC microgrid
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Fragility analysis of small-and medium-span bridges under region-specific traffic load characteristics 认领 引用
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作者 Gan Yang Shizhi Chen +1 位作者 Shuying Zhang Wanshui Han 《Journal of Highway and Transportation Research and Development(English Edition)》 2026年第2期82-94,共13页
Overloaded traffic loads can increase the risk of bridge damage and reduce the service life of bridges.To further refine the research on the fragility analysis of different small and medium span bridges to traffic loa... Overloaded traffic loads can increase the risk of bridge damage and reduce the service life of bridges.To further refine the research on the fragility analysis of different small and medium span bridges to traffic loads by considering the regional characteristics of traffic loads.This article systematically conducts a traffic load fragility analysis of bridges,taking into account the structural characteristics of small-and mediumspan bridges and vehicle load characteristics within the region.First,statistical analysis is conducted on the collected measured traffic load data within a certain area,and the Metropolis-Hasting sampling algorithm and Copula function are used to consider the correlation of traffic load parameters to simulate random traffic flow.Then,the calculation method for the resistance level corresponding to the three states of bridge cracking,yielding,and failure is given.Finally,eight types bridges with a high proportion within a certain route is selected,and their fragility to traffic loads has been analyzed.The analysis indicates that the failure probability corresponding to cracking conditions exceeds the serviceability limit state target for all hollow slab bridges,even when the vehicle load limit is set at 15 t.Similarly,T-beam bridges are also relatively easy to enter a state of working with cracks.Furthermore,hollow slab bridges exhibit a higher failure probability than T-beam bridges under identical traffic loading conditions.This indicates that T-beam bridges are more suitable for the current traffic load conditions.In hollow slab bridges,the failure probability of 13m span and 16m is relatively high.In T-beam bridges,the probability of failure is relatively high for 30m span.These bridges should receive more attention in operation and maintenance work.The proposed fragility analysis method for traffic loads can facilitate bridge operation and maintenance,while also guiding the formulation of vehicle load limit policies. 展开更多
关键词 bridge engineering traffic load fragility resistance level calculation load simulation vehicle-bridge coupling small-and mediumspan operation and maintenance
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Multi-pass intermittent local loading process of large-scale rib-web component:Forming characteristics and implementing apparatus 认领 引用 被引量：3
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作者 Dawei ZHANG Peng DONG +2 位作者 Jingxiang LI Zijian YU Shengdun ZHAO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第1期601-625,共25页
The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and redu... The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption. 展开更多
关键词 Forming characteristics Hydraulic system Intermittent local loading process Material flow Rib-web component
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High genetic load and recent anthropogenic bottleneck in the endangered Cupressus austrotibetica(Cupressaceae),Asia's tallest tree 认领 引用 被引量：1
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作者 Heng Yang Jialiang Li +10 位作者 Mi Yoon Chung Myong Gi Chung Zhitong Han Dayu Wu Jingge Kuang Xinran Zhang Xi Zhou Linning Bai Jianquan Liu Jian Luo Kangshan Mao 《Journal of Systematics and Evolution》 SCIE CSCD 2026年第1期125-137,共13页
Understanding the genetic diversity and genetic load of endangered species is essential for developing effective conservation strategies,particularly in ecologically sensitive regions such as the Himalayas.Cupressus a... Understanding the genetic diversity and genetic load of endangered species is essential for developing effective conservation strategies,particularly in ecologically sensitive regions such as the Himalayas.Cupressus austrotibetica,a rare conifer and the tallest recorded tree in Asia,reaching up to 102.3 m,faces substantial anthropogenic and environmental threats.To evaluate its genetic status,we sequenced transcriptomes of 54 individuals sampled across its restricted range and compared them with 96 individuals of C.gigantea,a closely related endangered species with broader distribution at higher elevations.Our analysis reveals that C.austrotibetica exhibits higher genetic diversity(π=0.0091)compared to C.gigantea(π=0.0042).Demographic analyses identified three historical bottleneck events in C.austrotibetica and two in C.gigantea,with two of these events coinciding with Quaternary climatic oscillations.Despite its relatively high genetic diversity,C.austrotibetica has a smaller effective population size based on Stairway Plot 2(Ne≈7200)than C.gigantea(Ne≈17600).Furthermore,C.austrotibetica harbors a higher proportion of severe deleterious mutations,while C.gigantea retains more moderate deleterious variants.These findings indicate that a recent anthropogenic bottleneck event has likely driven the reduced population size and increased genetic load in C.austrotibetica,emphasizing the urgent need for conservation priorities for this imperiled species. 展开更多
关键词 conservation endangered species genetic diversity genetic load small population
Multi-scale quantitative study on cemented tailings and waste-rock backfill under different loading rates 认领 引用 被引量：1
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作者 YIN Sheng-hua CHEN Jun-wei +4 位作者 YAN Ze-peng ZENG Jia-lu ZHOU Yun YANG Jian ZHANG Fu-shun 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第1期357-374,共18页
The development of metallic mineral resources generates a significant amount of solid waste,such as tailings and waste rock.Cemented tailings and waste-rock backfill(CTWB)is an effective method for managing and dispos... The development of metallic mineral resources generates a significant amount of solid waste,such as tailings and waste rock.Cemented tailings and waste-rock backfill(CTWB)is an effective method for managing and disposing of this mining waste.This study employs a macro-meso-micro testing method to investigate the effects of the waste rock grading index(WGI)and loading rate(LR)on the uniaxial compressive strength(UCS),pore structure,and micromorphology of CTWB materials.Pore structures were analyzed using scanning electron microscopy(SEM)and mercury intrusion porosimetry(MIP).The particles(pores)and cracks analysis system(PCAS)software was used to quantitatively characterize the multi-scale micropores in the SEM images.The key findings indicate that the macroscopic results(UCS)of CTWB materials correspond to the microscopic results(pore structure and micromorphology).Changes in porosity largely depend on the conditions of waste rock grading index and loading rate.The inclusion of waste rock initially increases and then decreases the UCS,while porosity first decreases and then increases,with a critical waste rock grading index of 0.6.As the loading rate increases,UCS initially rises and then falls,while porosity gradually increases.Based on MIP and SEM results,at waste rock grading index 0.6,the most probable pore diameters,total pore area(TPA),pore number(PN),maximum pore area(MPA),and area probability distribution index(APDI)are minimized,while average pore form factor(APF)and fractal dimension of pore porosity distribution(FDPD)are maximized,indicating the most compact pore structure.At a loading rate of 12.0 mm/min,the most probable pore diameters,TPA,PN,MPA,APF,and APDI reach their maximum values,while FDPD reaches its minimum value.Finally,the mechanism of CTWB materials during compression is analyzed,based on the quantitative results of UCS and porosity.The research findings play a crucial role in ensuring the successful application of CTWB materials in deep metal mines. 展开更多
关键词 cemented backfill waste rock loading rate multi-scale analysis mercury intrusion porosimetry pore structure micromorphology
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Fracture characteristics and fracture interface buckling mechanism of cantilever rock mass under non-uniformly distributed load 认领 引用 被引量：1
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作者 Wenlong Shen Ziqiang Chen +7 位作者 Meng Wang Jianbiao Bai Zhengyuan Qin Tongqiang Xiao Ningkang Meng Juntao Liu Yan Gai Hua Nan 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2026年第2期375-397,共23页
This study examined non-uniform loading in goaf cantilever rock masses via testing,modeling,and mechanical analysis to solve instantaneous fracture and section buckling from mining abutment pressure.The study investig... This study examined non-uniform loading in goaf cantilever rock masses via testing,modeling,and mechanical analysis to solve instantaneous fracture and section buckling from mining abutment pressure.The study investigates the non-uniform load gradient effect on fracture characteristics,including load characteristics,fracture location,fracture distribution,and section roughness.A digital model for fracture interface buckling analysis was developed,elucidating the influence of non-uniform load gradients on Fracture Interface Curvature(FIC),Buckling Rate of Change(BRC),and Buckling Domain Field(BDF).The findings reveal that nonlinear tensile stress concentration and abrupt tensile-compressive-shear strain mutations under non-uniform loading are fundamental mechanisms driving fracture path buckling in cantilever rock mass structures.The buckling process of rock mass under non-uniform load can be divided into two stages:low load gradient and high gradient load.In the stage of low gradient load,the buckling behavior is mainly reflected in the compression-shear fracture of the edge.In the stage of high gradient load,a buckling band along the loading direction is gradually formed in the rock mass.These buckling principles establish a theoretical basis for accurately characterizing bearing fractures,fracture interface instability,and vibration sources within overlying cantilever rock masses in goaf. 展开更多
关键词 Cantilever rock mass Non-uniformly distributed load Fracture characteristics Buckling fracture Digital model
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Spatial vibration analysis of thin-walled box girders subject to moving random loads considering the shear effect 认领 引用 被引量：1
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作者 Yong Cai Laifu Zhang +1 位作者 Qiqi Feng Xiaoyong Lv 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第4期195-210,共16页
This research provides analytical solutions to assess the bending-torsional vibration behavior of a thin-walled box girder subjected to moving random loads.The governing equations of a thin-walled box girder have been... This research provides analytical solutions to assess the bending-torsional vibration behavior of a thin-walled box girder subjected to moving random loads.The governing equations of a thin-walled box girder have been formulated to incorporate the impact of shear effect.The technique of integral transformation and the method of statistical analysis are employed to determine the average and standard deviation of the displacements at mid-span.The research’s findings are compared with the results from the Newmark-βtechnique and the Monte Carlo method to validate the effectiveness of the proposed strategy.By analysing the parameters,it is confirmed that neglecting the shear effect can result in substantial underestimation of lateral displacement.Compared to the Euler-Bernoulli beam theory,which does not consider the shear effect,the proposed theory shows differences of up to 109%in the average value and 213%in the standard deviation.These analysis results provide a reference for the vibration analysis of thin-walled box girders. 展开更多
关键词 Analytical solutions Bending-torsional vibration Thin-walled box girder Moving random loads Shear effect
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Effects of Temperature,Loading Frequency,Stress Amplitude,and Stress Ratio on the Low-Cycle Fatigue Behavior of FeMnSiCrNi Shape Memory Alloys 认领 引用 被引量：1
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作者 Bo Xu Beihai Huang +4 位作者 Sen Tang Xiang Xu Huabei Peng Chong Wang Qingyuan Wang 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2026年第2期133-151,共19页
FeMnSi-based shape memory alloys(SMAs)have great applied potential to large-scale structures in civil engineering,especially as an aseismic structural material.Low-cycle fatigue performance is one of the most importan... FeMnSi-based shape memory alloys(SMAs)have great applied potential to large-scale structures in civil engineering,especially as an aseismic structural material.Low-cycle fatigue performance is one of the most important properties of FeMnSi-based SMA aseismic materials.However,the low-cycle fatigue behavior of such SMAs,especially the stress-controlled low-cycle fatigue behavior(with ratchetting effect),has not been clearly understood.In this work,the low-cycle fatigue behavior of the FeMnSiCrNi SMAs subjected to stress-controlled cyclic tension–compression loads is investigated,and the effects of temperature,loading frequency,stress amplitude,and stress ratio are addressed.By analyzing the cyclic stress–strain response,fatigue fracture surface morphology,dissipation energy,ratchetting strain,and equivalent damping ratio,the mechanisms behind the temperature-,loading frequency-,stress amplitude-,and stress ratio-dependent low-cycle fatigue behavior are discussed.The results show that the plasticity,martensitic transformation,and/or the ratchetting strain caused by their tension–compression asymmetry are the decisive factors affecting the low-cycle fatigue behavior of FeMnSiCrNi SMAs. 展开更多
关键词 FeMnSiCrNi shape memory alloy Low-cycle fatigue behavior Temperature Loading frequency Stress amplitude Stress ratio
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Simulation Analysis of Thermal Load and Ultimate Bearing Capacity of Hull Girder Under Cabin Fire 认领 引用 被引量：1
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作者 Chenfeng Li Guanchen Wei +2 位作者 Zixiong Kang Houyao Zhang Xueqian Zhou 《哈尔滨工程大学学报（英文版）》 CSCD 2026年第3期758-774,共17页
The hull structure may collapse or deform severely under fire conditions.In this study,the safety of a ship's cabin structure under fire is evaluated using a dual-zone large eddy fire scenario simulation method an... The hull structure may collapse or deform severely under fire conditions.In this study,the safety of a ship's cabin structure under fire is evaluated using a dual-zone large eddy fire scenario simulation method and a sequential thermo-mechanical coupling analysis method.Taking a three-compartment section of a naval surface ship as a case study,a machinery room fire scenario was simulated and the fire temperature field was analyzed.Through a dedicated data interface,the full-field time-varying temperature loads were mapped to the finite element model of the compartment section,thereby achieving thermo-mechanical coupled analysis of the cabin structure.The effects of thermal expansion on the hull structure under rising fire temperatures were considered in the evaluation of the residual load-bearing capacity of the cabin.The results indicate that the residual load-bearing capacity of the compartment is closely linked to the fire development stage.Temperature not only significantly affects the mechanical properties of steel but also influences the structural load-bearing capacity through thermally stresses. 展开更多
关键词 Ship and ocean engineering Cabin fire Fire simulation Thermal load Thermo-mechanical coupling analysis Residual bearing capacity
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Structural optimization of stress-bearing structures of nearly incompressible problems under design-dependent pressure loads 认领 引用 被引量：1
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作者 T.T.BANH N.T.Y.NGUYEN +1 位作者 H.P.BAN D.LEE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2026年第4期905-926,共22页
An efficient and innovative method is presented for the stress-related structural topology optimization(TO)in coupled mechanical-pressure systems by leveraging flexible polygonal meshes.With a polytopal composite fini... An efficient and innovative method is presented for the stress-related structural topology optimization(TO)in coupled mechanical-pressure systems by leveraging flexible polygonal meshes.With a polytopal composite finite element approach,the volumetric locking in nearly incompressible materials is reduced.A fluid-flow-based model is built,in which a design-dependent pressure variable is introduced to capture the loading conditions within the system.The P-norm approach consolidates the stress metrics into a global measure,while the clustered regional scaling and adaptive techniques enhance the solutions for stress-limited cases.The primary contributions of this work include a novel framework for addressing the stress challenges in coupled mechanical-pressure systems via flow-based modeling,the adaptability to both compressible and nearly incompressible materials,and the compatibility with diverse mesh types,including triangular,quadrilateral,and polygonal elements.The numerical examples demonstrate,for the first time,optimized topologies for nearly incompressible materials under stress constraints in coupled mechanical-pressure environments,emphasizing the unique strength of this approach. 展开更多
关键词 topology optimization(TO) stress-related problem design-dependent load near incompressibility mechanical-pressure system polytopal composite finite element
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Dynamic behavior of steel post/wood panel railway noise barriers under aerodynamic loads induced by high-speed trains 认领 引用 被引量：1
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作者 Dongyun Liu Chao Wang +3 位作者 Jaime Gonzalez-Libreros Andréas Andersson Lennart Elfgren Gabriel Sas 《Railway Engineering Science》 EI 2026年第1期55-84,共30页
Railway noise barriers are an essential piece of infrastructure for reducing noise propagation.However,these barriers experience aerodynamic loads generated by high-speed trains,leading to dynamic effects that may com... Railway noise barriers are an essential piece of infrastructure for reducing noise propagation.However,these barriers experience aerodynamic loads generated by high-speed trains,leading to dynamic effects that may compromise their fatigue capacity.The most common structural design for railway noise barriers consists of vertical configurations of posts and panels.However,there have been few dynamic analyses of steel post/wood panel noise barriers under train-induced aerodynamic loads.This study used dynamic finite element analysis to assess the dynamic behavior of such noise barriers.Analysis of a 40-m-long noise barrier model and a triangular simplified load model,the latter of which effectively represented the detailed aerodynamic load,were first used to establish the model and input of the moving load during dynamic simulation.Then,the effects of different parameters on the dynamic response of the noise barrier were evaluated,including the damping ratio,the profile of the steel post,the span length of the panel,the barrier height,and the train speed.Gray relational analysis indicated that barrier height exhibited the highest correlations with the dynamic responses,followed by train speed,post profile,span length,and damping ratio.A reduction in the natural frequency and an increase in the train speed result in a higher peak response and more pronounced fluctuations between the nose and tail waves.The dynamic amplification factor(DAF)was found to be related to both the natural frequency and train speed.A model was proposed showing that the DAF significantly increases as the square of the natural frequency decreases and the cube of the train speed rises. 展开更多
关键词 Aerodynamic load Dynamic amplification factor Dynamic behavior Finite element analysis High-speed train Railway noise barrier
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Long-term mechanical loading aggravates osteoarthritis through a pro-apoptotic inflammatory microenvironment 认领 引用 被引量：1
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作者 Shiyun Shen Tianshun Fang +8 位作者 Jiabao Dong Junjie Li Miyang Xu Jian Wu Jiangfeng Zhang Jianyou Li Wei Liu Wei Zhou Xiongfeng Li 《Journal of Biomedical Research》 CAS CSCD 2026年第2期134-146,共13页
Articular cartilage maintains joint homeostasis by adapting to mechanical loading,but both insufficient and excessive loading can impair cartilage integrity.Whether mechanical activity should be restricted in early os... Articular cartilage maintains joint homeostasis by adapting to mechanical loading,but both insufficient and excessive loading can impair cartilage integrity.Whether mechanical activity should be restricted in early osteoarthritis(OA),particularly among exercise enthusiasts,remains controversial.Here,we established in vitro and in vivo models of prolonged moderate mechanical loading(7.5%strain,1 Hz)and analyzed human cartilage from weight-bearing and non-weight-bearing regions using RNA sequencing.Prolonged exposure(≥12 h)significantly increased chondrocyte apoptosis(2.3-fold),reduced expression of the chondrogenic transcription factor SOX9 and the matrix markers COL2A1,and elevated nerve growth factor(NGF)expression(1.8-fold),accompanied by enrichment of neural sensitization and inflammatory pathways.Immunofluorescence staining revealed NGF accumulation in mechanically stressed cartilage.Unlike high-intensity stress,which led to immediate apoptosis,moderate loading induced a delayed pro-apoptotic response after 12 h.These findings indicate that prolonged moderate mechanical loading may promote chondrocyte apoptosis through an NGFmediated inflammatory microenvironment and provide mechanistic evidence suggesting that patients with early OA may benefit from limiting high-impact or prolonged moderate-intensity exercise sessions to prevent cartilage damage and guide rehabilitation. 展开更多
关键词 osteoarthritis mechanical loading
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Mitigating the Dynamic Load Altering Attack on Load Frequency Control with Network Parameter Regulation 认领 引用
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作者 Yunhao Yu Boda Zhang +4 位作者 Meiling Dizha Ruibin Wen Fuhua Luo Xiang Guo Zhenyong Zhang 《Computers, Materials & Continua》 SCIE EI 2026年第2期1561-1579,共19页
Load frequency control(LFC)is a critical function to balance the power consumption and generation.Thegrid frequency is a crucial indicator for maintaining balance.However,the widely used information and communication ... Load frequency control(LFC)is a critical function to balance the power consumption and generation.Thegrid frequency is a crucial indicator for maintaining balance.However,the widely used information and communication infrastructure for LFC increases the risk of being attacked by malicious actors.The dynamic load altering attack(DLAA)is a typical attack that can destabilize the power system,causing the grid frequency to deviate fromits nominal value.Therefore,in this paper,we mathematically analyze the impact of DLAA on the stability of the grid frequency and propose the network parameter regulation(NPR)to mitigate the impact.To begin with,the dynamic LFC model is constructed by highlighting the importance of the network parameter.Then,we model the DLAA and analyze its impact on LFC using the theory of second-order dynamic systems.Finally,we model the NPR and prove its effect in mitigating the DLAA.Besides,we construct a least-effort NPR considering its infrastructure cost and aim to reduce the operation cost.Finally,we carry out extensive simulations to demonstrate the impact of the DLAA and evaluate the mitigation performance of NPR.The proposed cost-benefit NPR approach can not only mitigate the impact of DLAA with 100%and also save 41.18$/MWh in terms of the operation cost. 展开更多
关键词 Smart grid cybersecurity dynamic load altering attack load frequency control network parameter modification
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Severe load spectrum development for transport aircraft from measured load data:A representative flight method 认领 引用
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作者 Kunyu WEI Xiaofan HE 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第5期347-363,共17页
The development of severe load spectrum is essential for evaluating the durability and damage tolerance of transport aircraft structure to ensure safety and economic viability.However,traditional methods have lacked c... The development of severe load spectrum is essential for evaluating the durability and damage tolerance of transport aircraft structure to ensure safety and economic viability.However,traditional methods have lacked consensus on severity selection and often distort load sequences,which undermines reliability in full-scale fatigue testing.This study introduces a novel framework for developing high-fidelity severe Flight-by-Flight(F-B-F)spectrum from measured fleet load data.Statistical modelling of load variations within a specific transport aircraft fleet is used to establish severe damage criteria.Subsequently,flight data meeting these criteria are extracted to develop a severe load spectrum that accurately reproduces the actual severe load sequences.The accuracy and reliability of the spectrum developed are validated through fatigue tests on 2024-T3 aluminum alloy specimens with a centered hole.This approach bridges the gap between severe damage quantification and spectrum development,providing a robust method for generating reliable severe F-B-F spectrum. 展开更多
关键词 Fatigue damage Fatigue load Fatigue testing Representative flight Spectrum analysis Severe load spectrum
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Assessment of Regional Structural Optimality in a 2D Synthetic Proximal Femur Model under Varying Loading Angles 认领 引用
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作者 Jisun Kim Jung Jin Kim 《Computer Modeling in Engineering & Sciences》 SCIE EI 2026年第5期853-881,共29页
Synthetic proximal femur models avoid the ethical and technical limitations of human specimens and thus serve as an effective alternative for studying the proximal femur.This structure is directly connected to the hip... Synthetic proximal femur models avoid the ethical and technical limitations of human specimens and thus serve as an effective alternative for studying the proximal femur.This structure is directly connected to the hip joint,endures complex multi-directional loads,and exhibits region-specific structural adaptations due to its unique triangular geometry.However,most previous studies have examined only global load distributions or restricted regions,limiting the understanding of regional structural optimality.Therefore,this study aims to quantitatively evaluate the load adaptability and structural optimality of the proximal femur across individual regions of interest(ROIs).Three types of 2D finite element models of synthetic proximal femur models are generated.Structural analyses are then performed by varying the loading angles of hip contact and muscle forces.Finally,the proximal femurs are divided into different sizes of grids,and the load adaptability of different ROIs was to evaluated regional structural optimality.The proximal femur exhibited region-specific differences in structural optimality and load adaptability under varying loading angles.The femoral head and greater trochanter exhibited high conformity,while the femoral neck showed consistently low conformity,demonstrating that local anatomical features play a decisive role in load adaptability.Lower model resolution reduced predictive accuracy,whereas increasing ROI size improved stability by reducing local variability.This study establishes a quantitative framework for assessing regional structural optimality in synthetic proximal femurs.The findings demonstrate anatomy-dependent load adaptability and provide foundational insight for future 3D modeling and clinical translation. 展开更多
关键词 Synthetic proximal femur models structural optimality load adaptability finite element analysis conformity index loading angles
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The stress transfer mechanism of nacre-like composites under off-axis tensile loading 认领 引用
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作者 Peng Jiang Guangming Xia +5 位作者 Shi Bai Dongfang Xu Jixiang Qi Xun Xiong Xianben Ren Ying Li 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第2期466-472,共7页
Nacre exhibits excellent mechanical properties attributed to the staggered alignment of inorganic minerals and bio-organic materials.This study aims to understand how stress transfers from macro-scale loading conditio... Nacre exhibits excellent mechanical properties attributed to the staggered alignment of inorganic minerals and bio-organic materials.This study aims to understand how stress transfers from macro-scale loading conditions to the staggered architecture,revealing multiple stress transfer modes in nacre-like composites under off-axis tensile loading conditions.We propose an innovative off-axis tension-shear chain model,which predicts the trend of the equivalent modulus.Systematic optimization reveals a counter-intuitive result:the equivalent modulus at a certain angle can be smaller than the equivalent moduli in both principal directions,and this phenomenon differs from the monotonic behavior commonly observed in continuous fiber composite materials. 展开更多
关键词 Composites Load transfer Nacre Bioinspired Architected materials
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Quantifying the relative contributions of climate change and human activities to runoff and sediment load variations:a case study of the Yellow River Basin in Gansu Province,China 认领 引用
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作者 WU Lei ZHANG Kunwei +3 位作者 JIA Jieqiong ZHAI Peiqi CAO Jinjia HE Zheng 《Journal of Mountain Science》 SCIE CSCD 2026年第3期990-1005,共16页
The variation laws of runoff and sediment load under different climate,vegetation,and human activity scenarios are significantly different.Exploring the impacts of climate change and human activities on runoff and sed... The variation laws of runoff and sediment load under different climate,vegetation,and human activity scenarios are significantly different.Exploring the impacts of climate change and human activities on runoff and sediment load dynamics can provide a profound understanding of the mechanism of runoff and sediment load variability in basins,which is crucial for the sustainable development of regional ecosystems.This study investigates the Tao River Basin(TRB)on the Tibetan Plateau,as well as the Zuli River Basin(ZRB)and Jing River Basin(JRB)on the Loess Plateau,to differentiate the impacts of climate change and human activities on runoff and sediment load dynamics.The runoff and sediment load of the three watersheds have shown a decreasing trend over the past 40 years,and combined with the DMC(Dual mass curve)method,it was found that the slope of the runoff sediment gradually tends to flatten out.After the time period was divided,the CA(Cumulative anomaly)method was used for verification,which revealed good correspondence between the two before 2000 and then gradual deviations.The power function best represents the relationship between runoff and sediment load.During the initial period,climate had a significant impact on runoff variation in the TRB and JRB,with contribution rates of-54.93%and-63.02%,respectively.In the later period,human activities became the dominant influence,contributing more than-60%of the runoff variation.In the ZRB,human activities consistently dominated runoff variation,with contribution rates of-72.72%and-55.66%during both periods.In the early stages of research,the impact of climate change on sediment load was more severe in the TRB and JRB,and human activities played a significant role in the later stages.However,in the ZRB,human activities have always been the main contributor.Based on the actual local situation,runoff and sediment load in the TRB are influenced primarily by engineering measures,and vegetation and check dams exert greater impacts on the ZRB and JRB.This study explores the attribution of water and sediment load changes in different ecological geographic regions from a comparative perspective,providing a valuable theoretical basis and reference for understanding global runoff and sediment transport changes in similar areas. 展开更多
关键词 Runoff Sediment load Attribution analysis Budyko equation Basin comparison
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Dynamic behavior of track(rack)-bridge system under running vehicle and temperature load in rack railway 认领 引用
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作者 Zhihui Chen Lang Wang +2 位作者 Zhixian Chen Zhaowei Chen Jizhong Yang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2026年第1期526-536,共11页
Significant diurnal temperature variations in mountainous rack railways cause stiffness mismatches between the rack structure and simply supported bridges,leading to critical failures like bolt loosening and rack frac... Significant diurnal temperature variations in mountainous rack railways cause stiffness mismatches between the rack structure and simply supported bridges,leading to critical failures like bolt loosening and rack fractures.This study develops a dynamic model of the vehicle-rack-bridge system based on train-track-bridge interaction theory,integrating gear-rack meshing and wheel-rail contact mechanisms.The model analyzes the dynamic response of bridges with varying spans under combined thermal and dynamic loading.Numerical simulations,conducted using finite element analysis,reveal peak vibration accelerations of 1.3 m/s2for the rack,3.0 m/s2for the rail,1.2 m/s2for the sleeper,and 0.1 m/s2for the bridge,with maximum stresses of 3 MPa in the rack,8 MPa in the rail,and 25 MPa in connecting bolts.The results show significant span-dependent amplification of stress and strain in the rack system under thermo-mechanical loading,exceeding material strength limits at 60-meter spans.An innovative elastic connection method is proposed to mitigate stress concentrations effectively,en-hancing system durability.This study introduces a novel approach to modeling complex thermo-mechanical interactions in rack railway systems,validated through extensive simulations,and provides a practical solution for improving structural resilience,offering theoretical guidance for optimizing rack-bridge system design to ensure operational safety in extreme environmental conditions. 展开更多
关键词 Simply supported bridge Rack railway Bridge-track interaction Temperature loads Dynamic Mechanical
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