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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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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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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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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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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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Ag-loading boosts full-spectrum photocatalysis performance of Bi2 WO6:Yb3+,Er3+ 认领 引用
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作者 Xuemei Lu Xin Guo +7 位作者 Xiaoxuan Fan Wen Liu Xu Gao Hainan Li Jialin Wang Yang Zhao Jiwei Wang Kexin Wang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2026年第5期1453-1463,共11页
Currently,one of the main factors limiting the performance of photocatalytic technology is the suboptimal utilization efficiency of the infrared region in sunlight spectrum.Although rare earth ion doping can improve l... Currently,one of the main factors limiting the performance of photocatalytic technology is the suboptimal utilization efficiency of the infrared region in sunlight spectrum.Although rare earth ion doping can improve light absorption of photocatalysts in the infrared region to some extent,it is still restricted by a narrow absorption cross-section and relatively low photocatalytic efficiency under infrared light.In this work,a full-spectrum photocatalyst based on Bi2 WO6:Yb3+,Er3+/Ag composite was prepared.Ag loading formed a Schottky junction on the surface of Bi2 WO6 and introduced the localized surface plasmon resonance(LSPR)effect.Their synergistic interaction optimized the band structure and the separation efficiency of photogenerated charge carriers.Hot electron injection induced by the LSPR effect can simultaneously enhance the mutually independent photocatalytic processes driven by visible light and near-infrared light,thereby achieving an overall boost in full-spectrum photocatalytic performance.It enables Bi2 WO6:Yb3+,Er3+/Ag composite to efficiently address various refractory pollutants and complex conditions.Bi2 WO6:Yb3+,Er3+/Ag composite exhibits outstanding photodegradation performance for a diverse mixture of antibiotics,including tetracycline hydrochloride,norfloxacin,ciprofloxacin,and levofloxacin in real water samples under simulated sunlight irradiation.This work paves a way for the development of green,efficient,and sustainable environmental remediation technologies. 展开更多
关键词 Photocatalysis Precious metal loading Degradation Rare earth doping Upconversion
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Thallium(Ⅰ)retention in porous media is restricted by elevated Mn(Ⅱ)and Fe(Ⅲ)loadings:Insights into suitability between media and microbial communities 认领 引用
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作者 Yuheng Huang Xiaoling Zhang +3 位作者 Ziqiang Liu Xiaoliu Huangfu Qiang He Suyan Pang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第6期665-675,共11页
In tailings permeated by leachate containing thallium(Tl),manganese oxides(MnO x)are recognized as critical substances in immobilizing Tl and preventing its further migration into groundwater.However,dissolved Mn(... In tailings permeated by leachate containing thallium(Tl),manganese oxides(MnO x)are recognized as critical substances in immobilizing Tl and preventing its further migration into groundwater.However,dissolved Mn(Ⅱ)and Fe(Ⅲ)also exist in micro-oxic environments.The effects and mechanisms of the increased levels of these coexisting ions,driven by environmental processes such as rainfall leaching,on Tl(Ⅰ)retention remain largely unclear.This study established two systems using natural manganese sand and limestone sand as porous media,demonstrating that the elevated Mn(Ⅱ)/Fe(Ⅲ)loadings weakened Tl(Ⅰ)retention.Redundancy analysis identified media type and depth as primary factors shaping microbial communities,which subsequently influenced Tl(Ⅰ)immobilization.Manganese sand exhibited superior recovery capacity compared to limestone sand under higher Mn(Ⅱ)and Fe(Ⅲ)loadings.Co-occurrence network analyses revealed that media-microorganism suitability governs microbial community structure and heavy metal retention efficiency.Hydraulic impact and dissolved organic/inorganic cations reduced MnO x content,while the higher retention capacity of manganese sand was attributed to the presence of microorganisms with higher activity and abundance,as well as an increased abundance of microbial-generated MnO_( x).This study offers novel insights into the mechanisms underlying Tl(Ⅰ)retention in tailings,which is crucial for comprehending its environmental fate. 展开更多
关键词 Thallium Restricted retention Porous media Elevated loadings Co-occurrence network
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A dual capillary contraction-induced prestressing strategy for high-loading Si/C anode with long cycling stability 认领 引用
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作者 Yanpeng Wang Fenghua Liu +6 位作者 Yusheng Luo Zhaoyang Song Zezhong Li Xiaomei Chen Shuang Liu Ke Gong Wei Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2026年第6期287-295,I0008,共9页
Silicon(Si)is a leading anode candidate for high-energy-density lithium-ion batteries due to its exceptional theoretical specific capacity.However,its practical application is hindered by particle fracture under high ... Silicon(Si)is a leading anode candidate for high-energy-density lithium-ion batteries due to its exceptional theoretical specific capacity.However,its practical application is hindered by particle fracture under high areal loadings and the inherent trade-off between electrode density and ion transport kinetics.Herein,we propose a“dual capillary contraction”strategy to construct a dense,structurally robust silicon-based anode(Si@SA@GO).This method uses nano-CaCO3 as a sacrificial filler between graphene oxide(GO)layers,creating a“filled capillary”effect that amplifies contraction forces during initial drying.Subsequent removal of the filler generates nanopores,which then trigger an intense“hyper-contraction”driven by Young-Laplace pressure in a secondary drying stage.This cascaded process forges a pretensioned GO network that tightly confines Si nanoparticles,actively imposing compressive stress to counteract their volumetric expansion.The resulting electrode successfully resolves the conflict between density and structural stability,achieving a remarkable tap density of 0.84 g cm-3,while maintaining efficient ion transport pathways.The Si@SA@GO anode delivers an ultrahigh areal capacity of 8.5 mAh cm-2,with 75%capacity retention after 1000 cycles in the Si@SA@GO//LFP full cell.This work provides a scalable and effective route to resolve the long-standing trade-offs among density,stress,and kinetics in high-performance silicon anodes. 展开更多
关键词 Contraction Silicon anode High density High loading Lithium ion storage
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The recrystallization mechanism and its effects on texture in pre-twinned AZ31 magnesium alloy during medium-high temperature impact loading 认领 引用
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作者 Xiao Liu Xiaofeng Zhang +6 位作者 Biwu Zhu Chao Xie Bibo Hu Wenhui Liu Luoxing Li Congchang Xu Pengcheng Guo 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2026年第1期459-475,共17页
Investigating effect of recrystallization mechanism on deformation mode and texture evolution is conducive to controlling deformation mechanism and texture in magnesium alloys under medium-high temperature impact load... Investigating effect of recrystallization mechanism on deformation mode and texture evolution is conducive to controlling deformation mechanism and texture in magnesium alloys under medium-high temperature impact loading.In the present study,a Johnson-Cook model incorporating twin strengthening was established to simulate macro-deformation,and a twinning induced recrystallization(TDRX)model and bulging recrystallization(GBBDRX)model are introduced into visco-plastic self consistant(VPSC)framework to quantitatively study the deformation mechanism of pre-twinned AZ31 magnesium alloy during medium-high temperature impact loading.Both TDRX and GBBDRX occur,with basal slip as the dominant slip system,followed by pyramidal〈c+a〉slip and prismatic slip.The dynamic recrystallization(DRX)significantly influences basal and pyramidal〈c+a〉slip systems,with minimal impact on secondary deformation mechanism.In addition,the recrystallization mechanism of grain boundary bowing increases the activity of basal slip and decreases the activity of pyramidal〈c+a〉slip.The nucleation and growth of recrystallized grains enhance basal slip activity and suppress pyramidal〈c+a〉slip,leading to the formation of a strong basal texture.As dynamic recrystallization progresses,a bimodal texture develops,characterized by a reduction in basal component pole density and a more pronounced basal slip. 展开更多
关键词 Az31 magnesium alloy Texture Deformation mode Dynamic recrystallization Impact loading
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Damage behavior of soaked sandstone subjected to cyclic loadings 认领 引用
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作者 Zhenhui Bi Lei Wang +3 位作者 Chunhe Yang Yintong Guo Wuhao Guo Mingnan Xu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第2期1090-1107,共18页
Large-scale geological energy storage plays a crucial role in balancing the intermittency of renewable energy.As an energy storage medium,soaked sandstone has a wide range of applications in geological energy storage.... Large-scale geological energy storage plays a crucial role in balancing the intermittency of renewable energy.As an energy storage medium,soaked sandstone has a wide range of applications in geological energy storage.Understanding the damage characteristics in soaked sandstones is essential for ensuring the stability and longevity of these energy storage systems.This study involved multi-stage cyclic loading tests conducted on soaked sandstone to explore the damage evolution throughout the loading process.The findingsreveal several important insights:(1)The plastic hysteresis loops observed during multi-stage cyclic loading evolved from dense to sparse.An increase in stress level led to greater damage in the rock,as evidenced by an increase in accumulated peak/plastic strains.(2)Energy density and stress level are related by quadratic polynomial relationships.The elastic and dissipated energy densities are related by a linear law.The average energy storage coefficientdecreased by up to 24.1%with increasing stress amplitude,reflectingchanges in energy dynamics within the samples.(3)AE counts,amplitude,and frequency provided critical insights into rock damage and fracture patterns.The greater the loading rate and stress amplitude,the lower the proportion of high-amplitude,high-peak frequency,and shear-type fractures.Increasing stress amplitude caused a maximum 16.63%reduction in the AE bvalue,indicating shifts in fracture behavior under varying stress conditions.(4)The increase in loading rate and stress amplitude promotes the transformation of micropores and mesopores to macropores/microcracks.(5)Damage variables,definedin terms of cumulative dissipation energy,aligned closely with the fatigue damage model under multi-stage cyclic loading.Accelerated damage primarily occurred during the finalstages of fatigue loading,highlighting critical periods in the degradation of soaked sandstones.This study can offer guidance for designing operational parameters for energy storage geological bodies dominated by soaked sandstones. 展开更多
关键词 Soaked sandstone Multi-stage cyclic loading Energy density Acoustic emission Microstructure Damage evaluation
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Mechanical response and brittle-ductile transition of porous sandstone under true-triaxial loading 认领 引用
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作者 Junjie Xiao Xing Li +2 位作者 Jiacun Liu Dongping Liu Kaiwen Xia 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第5期3394-3406,共13页
This study investigates the influence of mean stress and Lode angle on the mechanical behavior of porous sandstone.Sandstone specimens were tested using a newly developed true-triaxial loading apparatus under five con... This study investigates the influence of mean stress and Lode angle on the mechanical behavior of porous sandstone.Sandstone specimens were tested using a newly developed true-triaxial loading apparatus under five constant Lode angle conditions and seven different mean stresses,covering a transition from brittle to ductile regimes.Based on the experimental results,three types of stress-strain responses were identified,transitioning progressively from Type 1,through Type 2 to Type 3 as the mean stress increases.Type 1 response represents typical brittle behavior,characterized by prominent shear fractures.Type 2 response corresponds to the brittle-ductile transition behavior,exhibiting non-penetrating shear fractures.Type 3 response is associated with ductile behavior,characterized by no visible shear fractures.The deviatoric stress initially increases and then decreases with increasing mean stress,forming a cap surface in the meridian plane.A generalized failure criterion is subsequently developed,capable of accurately characterizing this strength response.Furthermore,the brittle-ductile transition behavior is found to be significantly dependent on the Lode angle.Finally,the brittle-ductile transition boundary is described,incorporating the dependence of Lode angle. 展开更多
关键词 True-triaxial loading Lode angle Brittle-ductile transition Porous sandstone Failure surface
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Mechanical behavior of granite under cyclic loading after a seawater cyclic thermal shock 认领 引用
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作者 Wenfeng Shen Wei Wang +3 位作者 Xuelei Duan Shifan Liu Hao Wang Qizhi Zhu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第4期2776-2793,共18页
The ocean,islands,and coastal areas represent significantpotential for geothermal energy development,owing to the abundant seawater resources serving as an efficientheat exchange medium.To study the mechanical behavio... The ocean,islands,and coastal areas represent significantpotential for geothermal energy development,owing to the abundant seawater resources serving as an efficientheat exchange medium.To study the mechanical behavior of granite under cyclic loading after cyclic thermal shock,a laboratory triaxial cyclic loading and unloading test was carried out.This paper presents the results of a study on the deformation behavior,mechanical properties,and failure modes of granite after 0–30 cycles of seawater thermal shock at 400℃.The experimental results show that the axial and circumferential plastic deformations increase monotonically with the number of cycles(N),while the elastic modulus changes nonlinearly.The computed tomography(CT)results indicate that seawater thermal shock cycles cause the formation of cracks on the granite surface.With an increase in the number of thermal shock cycles,the cracks gradually increase and expand inwards,resulting in a rise of 93.84%in axial strain and a decrease of 29.02%in failure strength(σc).Furthermore,the occurrence of shear failure is predominantly observed in the damaged granite,and shear-induced cracks form along the shear fractures when the number of thermal shock cycles exceeds 6.However,after three cycles of thermal shock,the failure surface of the granite exhibits characteristics of shear splitting failure,and theσcincreases by 14.96%. 展开更多
关键词 Geothermal exploitation Cyclic thermal shock Cyclic loading Mechanical characteristics Plastic deformation
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Dilatancy and long-term stability of deep salt caverns under cyclic loading 认领 引用
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作者 JI Zhen-xing QIN Ken +4 位作者 LIU Jian-feng WANG Gui-jiu YANG Jian-xiong YI Hai-yang WEI Jin-bing 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第5期2189-2209,共21页
Constructing salt caverns in deep formations poses significant challenges due to their high geostresses,pronounced creep behavior,and particularly intense pressure fluctuations.This study first conducted mechanical ex... Constructing salt caverns in deep formations poses significant challenges due to their high geostresses,pronounced creep behavior,and particularly intense pressure fluctuations.This study first conducted mechanical experiments to investigate the long-term creep behavior of salt rock and to examine the differences in its mechanical response under cyclic loading compared with traditional triaxial loading.The results revealed a confining-pressure-dependent nonlinear creep behavior as well as a degradation mechanism induced by cyclic loading.A numerical model was then developed that incorporates the nonlinear creep law with periodic parameter weakening.Comparative analyses of cavern dilatancy under cyclic versus constant pressure conditions were conducted,validating the necessity of integrating the periodic weakening mechanism into the numerical model.The results indicate that cyclic loading enhances the plastic deformation capacity while lowering its dilatancy threshold.For the cyclic gas pressure(CGP)mode,a minimum operational pressure of 9.6 MPa is infeasible due to excessive sidewall convergence and extensive spalling risk zones,with 12.0 MPa recommended as the lower limit.The constant brine pressure(CBP)mode exhibits superior performance in controlling deformation and damage.For the constant gas pressure(GP)mode,a constant pressure of 19.2 MPa results in no significant dilatancy damage zones in the salt layer.Critically,neglecting the dynamic weakening of parameters induced by cyclic loading leads to substantial underestimation of long-term deformation,by 20.2%in this study,primarily accumulated during the unloading(gas production)phase.The findings are expected to provide valuable insights into deep salt caverns with high-pressure fluctuations. 展开更多
关键词 deep salt cavern cyclic loading dilatancy cyclic gas pressure constant brine pressure
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Structural deterioration and instability in grouted reinforcement crushed rock masses subjected to increasing-amplitude fatigue loading 认领 引用
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作者 LI Ju-zhou LI Chang-hong +2 位作者 TAHERI Abbas LI Peng MA Dan 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第2期783-801,共19页
To investigate the influence of different Talbot grading indices(n-values)on the fatigue damage deterioration and instability behavior of grouted reinforcement body,an increasing-amplitude fatigue loading test was con... To investigate the influence of different Talbot grading indices(n-values)on the fatigue damage deterioration and instability behavior of grouted reinforcement body,an increasing-amplitude fatigue loading test was conducted on grouted reinforcement specimens with different n-values using the multi-functional electro-hydraulic servo-controlled rigidity test system(MTS-815).Acoustic emission(AE)technology was employed to monitor the entire testing process.The fatigue mechanical response mechanism,AE characteristic parameters,and damage modes were analyzed.The results demonstrate that as n-value increases,the mechanical characteristics of the specimens initially increase and then decrease.AE parameters,including the cumulative AE ring counts and energy counts,follow the same trend,and spectral characteristics exhibit a strong correlation with crack evolution.The cumulative AE ring counts damage model reveals a three-phase behavior for the specimens under different n-values.The b-value,which characterizes the scale distribution of cracking events,correlates with the volumetric strain growth rate,showing a more sensitive response.Differences in n-values directly affect the distribution of RA/AF signals and damage modes.The findings provide valuable insights into predicting the destabilization of grouted reinforcement specimens under fatigue disturbance and offer necessary theoretical support for the design and stability control of excavation in fragmented surrounding rock. 展开更多
关键词 grouted reinforcement specimens Talbot grading indices fatigue loading b-value damage model
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Research on the reliability of motion accuracy for ammunition conveyor in artillery automatic loading system 认领 引用
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作者 Guangsong Chen Junhua Chen +1 位作者 Jinsong Tang Yongji Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2026年第1期102-114,共13页
The automatic loading systems of artillery are critical for the accurate,efficient,and reliable delivery of pro-jectiles and propellants into the gun chamber.In modern artillery,the ammunition conveyor serves as the e... The automatic loading systems of artillery are critical for the accurate,efficient,and reliable delivery of pro-jectiles and propellants into the gun chamber.In modern artillery,the ammunition conveyor serves as the end effector of the automatic loading system,and its motion state significantly impacts the accuracy of projectiles.Therefore,it is of immense importance to precisely and effectively evaluate the reliability of the motion accuracy of the ammunition conveyor.This paper aims to propose a practical and efficient analysis method for evaluating the reliability of the motion accuracy of the ammunition conveyor.The proposed approach involves the use of a deep learning network to approximate the physical model and the extremum method to obtain a single cycle sequence decoupling strategy for solving the time-varying reliability issue of complex systems.Employing this strategy,the time-varying reliability of the ammunition conveyor is transformed into a static reliability problem.The proposed method includes the use of a deep feedforward neural network,second-order saddle point ap-proximation(SPA)method,extremum method,and efficient global optimization(EGO)technology.The results reveal that the reliability of the motion accuracy of the ammunition conveyor is 93.42%,with the maximum failure probability occurring at 0.21 s.These results serve as an important reference for the structural optimi-zation design of the ammunition conveyor based on reliability and the maintenance of the operational process. 展开更多
关键词 Automatic loading system Ammunition conveyor Motion accuracy Reliability Second-order saddle point approximation
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Mechanical response of porcine pia-arachnoid complex under high-strain rate tensile loading 认领 引用
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作者 Yongrou Zhang Jialuan Zhou +3 位作者 Ziji Yin Lingling Hu Jingyu Wang Liqun Tang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第6期575-588,共14页
The pia-arachnoid complex(PAC),functioning as a critical biomechanical interface between the skull and brain,requires precise dynamic characterization to improve traumatic brain injury(TBI)prediction under impact load... The pia-arachnoid complex(PAC),functioning as a critical biomechanical interface between the skull and brain,requires precise dynamic characterization to improve traumatic brain injury(TBI)prediction under impact loading.However,existing mechanical data for PAC under high-strain rate conditions remain scarce due to experimental challenges posed by its ultra-thin and low stiffness.Conventional metallic split Hopkinson bar systems encounter extremely weak signals when testing this tissue.In this study,we present the first high-strain rate dynamic tensile characterization of PAC.To address the challenge of weak transmission signals,a double-bullet electromagnetic driven split Hopkinson stretch bar system with polycarbonate bars was used.Three dynamic tensile tests were conducted at varying strain rates,achieving a maximum strain rate of 1800 s−1.Experimental results reveal significant strain rate sensitivity and nonlinear stress-strain behavior.A rate-dependent constitutive model for PAC was established based on the Yeoh hyperelasticity model and the Bernstein-Kearsley-Zapas viscoelastic theory.Model parameters were optimized using a hybrid approach combining particle swarm optimization and genetic algorithm.The proposed constitutive equation effectively captures the strain rate sensitivity and nonlinear mechanical characteristics of PAC across a wide range of strain rates.The measured dynamic properties and validated constitutive model provide essential biomechanical data for PAC,thereby advancing the predictive capability of TBI simulations under high-speed impact conditions. 展开更多
关键词 Pia-arachnoid complex High-strain rate tensile loading Split Hopkinson stretch bar Visco-hyperelastic constitutive model
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Frictional characteristics of rough granite fractures subjected to various normal loading/unloading rates and shear velocities 认领 引用
17
作者 ZHANG Chuan-jiu DUAN Hong-fei +5 位作者 LI Xing-ling BAI Zhen-chao LI Peng WANG Wei LI Xuan-liang DANG Wen-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第5期2243-2266,共24页
The shear behavior of rock joints under dynamic disturbances is still not well understood,especially when subjected to irregular stress waveforms,which are common in real-world scenarios.In this study,a series of cycl... The shear behavior of rock joints under dynamic disturbances is still not well understood,especially when subjected to irregular stress waveforms,which are common in real-world scenarios.In this study,a series of cyclic normal loading/unloading direct shear tests was conducted on rough granite fractures using a laboratory direct shear apparatus.The effects of different normal loading rates,unloading rates,and shear velocities on shear stress,apparent friction coefficient,normal displacement,and shear work were systematically analyzed.The experimental results indicated that as the normal loading and unloading rates increase and the shear velocity decreases,the peak shear stress and shear work decrease.Compared with quasi-static shear strength,dynamic normal stress disturbance may strengthen the dynamic shear strength or weaken it,and the strengthening/weakening degree is controlled by the normal loading/unloading rates and shear velocity.Furthermore,three distinct shear stress variation patterns(linear decay,nonlinear decay,and peak delay)are observed.These findings provide a theoretical basis for evaluating the stability of jointed rock masses under complex dynamic disturbances such as earthquakes,tidal effects,traffic loads,and blasting activities. 展开更多
关键词 rough granite fracture normal loading/unloading rates shear velocity frictional strengthening frictional weakening
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Theoretical Investigation of Double Carcass Hoses Under Combined Internal Pressure and Axial Loading 认领 引用
18
作者 GAO Song-lin AN Chen +3 位作者 WEI Dai-feng TAN Jian YANG Ren-jie Segen F.ESTEFEN 《China Ocean Engineering》 SCIE EI CSCD 2026年第2期317-332,共16页
As offshore oil and gas exploration advances into deeper waters,double carcass hoses(DCHs)are subjected to increasingly complex combined loading conditions,necessitating enhanced reliability and durability in extreme ... As offshore oil and gas exploration advances into deeper waters,double carcass hoses(DCHs)are subjected to increasingly complex combined loading conditions,necessitating enhanced reliability and durability in extreme environments.This paper presents a theoretical analysis methodology for evaluating the stress and deformation of DCHs under concurrent internal pressure and axial tensile forces.The approach,based on the laminated plate theory and Mooney-Rivlin model,incorporates the nonlinear characteristics of the rubber matrix and geometric nonlinearity within reinforcement layers.Through iterative loading processes,material parameters and reinforcement layer winding angles are systematically updated.The failure criteria are established using the maximum tensile strength of the cord and Von Mises criterion for helical steel wires.The model’s validity was verified through axial tensile tests on a DCH with a 500 mm inner diameter.The analysis reveals distinct variations in load-bearing contributions between helical steel wire and cord layers at different internal pressure levels.The hose demonstrates complex nonlinear behavior under combined loading conditions.Comprehensive sensitivity analyses examined the influence of critical parameters,including cord winding angle,layer count,hose diameter,helical steel wire pitch,and wire diameter,on hose failure characteristics.A failure envelope for DCHs under various parameter conditions was developed,providing a theoretical framework for optimizing DCH structural design. 展开更多
关键词 double carcass hose combined loading tensile test theoretical model sensitivity analysis failure envelope
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Effect of initial fracture angle on the failure pattern and gas flow channel of sandstone under multistage loading 认领 引用
19
作者 Quanle Zou Feixiang Lv +4 位作者 Zihan Chen Qingsong Li Jianjun Zhao Qican Ran Qingmiao Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第3期2142-2157,共16页
After coal seam mining,the overlying rock strata above the goaf are subjected to long-term stress and eventually undergo failure.Under mining-induced disturbances,the strata develop fractures at various angles,which s... After coal seam mining,the overlying rock strata above the goaf are subjected to long-term stress and eventually undergo failure.Under mining-induced disturbances,the strata develop fractures at various angles,which significantly influence failure modes and the morphology of gas flow channels.This study employed multistage loading experiments,numerical simulations,three-dimensional reconstruction,and image recognition to investigate the fragmentation process of rocks with different initial fracture angles under multistage loading.The results show that variations in the initial fracture angle affect the transmission of contact forces among rock particles.As the angle increases,the transmission pattern shifts from a uniform distribution to one extending along the direction of the fracture.Rocks with small initial fracture angles tend to experience tensile-dominated failure,with most of the material subjected to longitudinal loading,resulting in reduced strength.Fractures propagate from the central region of the initial fracture,producing a complex internal fracture network.The proportion of fracture channels varies considerably across regions,creating multiple zones of velocity variation in the gas flow.In contrast,rocks with large initial fracture angles are more susceptible to shear failure,with the primary load-bearing zones aligned along the inclined fracture direction.As a result,the influence on surrounding regions is limited,improving the rock's load-bearing capacity under multistage loading.In these cases,the distribution and proportion of fracture channels become more uniform,promoting more stable gas flow within the channels.Overall,these findings provide theoretical insights into how initial fracture angles govern rock failure patterns and gas flow characteristics. 展开更多
关键词 Multistage loading Initial fracture angle Failure pattern Gas flow characteristics Three-dimensional fracture reconstruction
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Investigation and prediction of material transfer in transitional region under local loading forming of large-scale rib-web components from perspective of multi-stage stress states 认领 引用
20
作者 Chao YANG Ke WEI +2 位作者 Fangbin WANG Yong HOU Wenzhen CHEN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第4期695-713,共19页
Titanium alloy large-scale rib-web components,known for their lightweight and highstrength properties,have the potential to substantially lighten the load-bearing components of aircraft.Isothermal Local Loading(ILL)ha... Titanium alloy large-scale rib-web components,known for their lightweight and highstrength properties,have the potential to substantially lighten the load-bearing components of aircraft.Isothermal Local Loading(ILL)has been recognized as an advanced technique for the integrated and less-loading forming of these components.However,material transfer in the transitional region during ILL often leads to folding defect near the die-partition line.To this end,the position of the neutral layer during ILL is calculated via the slab method,which is modified to align with the material flow in the transitional region,taking into account the multi-stage stress states under diverse boundary conditions.By utilizing this calculation model,the material transfer rate and rib-groove filling height can be ascertained.The material transfer rate serves as a criterion for predicting folding defect,and thereby an optimal billet is obtained and implemented in the ILL process.The results demonstrate that the material transfer rate is significantly decreased compared to the non-optimized billet,resulting in a non-folding component of transitional region. 展开更多
关键词 Isothermal local loading Large-scale rib-web component Multi-stage stress states Slab method Transitional region
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