检索结果-南通市图书馆

The Mixed-Mode Fatigue Crack Propagation Model of Piezoelectric Materials Under Electric Fatigue Loading by the Jk-Integral

引用

Acta Mechanica Solida Sinica 2024年第4期37卷 634-641页

作者： Xianghua Chen Chunguang Wang Qun Li The Institute of Xi’an Aerospace Solid Propulsion Technology Xi’an710025China state key laboratory for Strength and vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049China

The electric fatigue load has a significant effect on the crack propagation behavior and failure life of piezoelectric materials and devices. In this paper, an electrical mixed-mode fatigue crack propagation model for piezoelectric materials is proposed based on the piezoelectric Jk-integral theory. The crack initiation, propagation, and life prediction criteria of piezoelectric materials under electric fatigue loading are given by this model, and the finite element simulation model is established to study the electrical mixed-mode crack propagation behavior of piezoelectric structures. Meanwhile, the electrical mixed-mode fatigue crack propagation model is applied to the fatigue crack propagation behavior of a piezoelectric typical defective structure, the crack–hole interference model. The mixed-mode crack propagation, fatigue life, and the interference behavior between the crack and hole at various hole locations of the crack–hole interference model are well recognized by this model. The crack propagation behavior under different electrical load intensities is also considered. The results show that the hole in front of the crack tip inhibits crack propagation to a certain extent, and the strength of electrical load affects the fatigue life of piezoelectric materials and structures. Therefore, the proposed electrical mixed-mode fatigue crack propagation model provides a reference for predicting the mixed-mode fatigue crack propagation behavior and fatigue life of piezoelectric structures under electric fatigue loading.

关键词： Configurational force J k-integral Piezoelectric Mixed-mode crack propagation Life prediction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Inter-well internal resonance analysis of rectangular asymmetric cross-ply bistable composite laminated cantilever shell under transverse foundation excitation

引用

Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1353-1370页

作者： Lele REN Wei ZHANG Yufei ZHANG state key laboratory of Mechanical System and vibration Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanics Guangxi UniversityNanning 530004China Beijing key laboratory of Nonlinear vibrations and Strength of Mechanical Structures College of Mechanical EngineeringBeijing University of TechnologyBeijing 100124China

The chaotic dynamic snap-through and complex nonlinear vibrations are investigated in a rectangular asymmetric cross-ply bistable composite laminated cantilever shell,in cases of 1:2 inter-well internal resonance and primary *** transverse foundation excitation is applied to the fixed end of the structure,and the other end is in a free *** first-order approximate multiple scales method is employed to perform the perturbation analysis on the dimensionless two-degree-of-freedom ordinary differential motion control *** four-dimensional averaged equations are derived in both polar and rectangular coordinate *** from the obtained frequency-amplitude and force-amplitude response curves,a detailed analysis is conducted to examine the impacts of excitation amplitude,damping coefficient,and tuning parameter on the nonlinear internal resonance characteristics of the *** nonlinear softening characteristic is exhibited in the upper stable-state,while the lower stable-state demonstrates the softening and linearity *** simulation is carried out using the fourth-order Runge-Kutta method,and a series of nonlinear response curves are *** the excitation amplitude further elucidates the global bifurcation and chaotic dynamic snap-through characteristics of the bistable cantilever shell.

关键词： bistable composite laminated cantilever shell inter-well internal resonance primary resonance chaotic dynamic snap-through complex nonlinear vibration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Design, modeling, and evaluation of parallel continuum robots: A survey

引用

Science China(Technological Sciences) 2024年第3期67卷 673-695页

作者： CHEN GenLiang TANG ShuJie DUAN XuYang WANG Hao Meta Robotics Institute Shanghai Jiao Tong UniversityShanghai 200240China state key laboratory of Mechanical Systems and vibration Shanghai Jiao Tong UniversityShanghai 200240China Shanghai key laboratory of Digital Manufacturing for Thin-Walled Structures Shanghai Jiao Tong UniversityShanghai 200240China

Parallel continuum robots(PCRs) have attracted increasing attention in the robotics community due to their simplicity in structure,inherence with compliance, and easiness of realization. Over the past decade, a variety of novel designs have been reported to enrich their diversity. However, there is a lack of systematic review of these emerging robots. To this end, this paper conducts a comprehensive survey on the mechanism design, kinetostatic modeling and analysis, and performance evaluation. For these robots, kinetostatic modeling plays a fundamental role throughout the design, analysis, and control stages. A systematic review of the existing approaches for kinetostatic modeling and analysis is provided, and a comparison is made to distinguish their differences. As well, a classification is made according to the characteristics of structure and actuation. In addition, performance evaluation on the workspace, stability, and singularity is also overviewed. Finally, the scenarios of potential applications are elaborated, and future research prospects are discussed. We believe that the information provided in this paper will be particularly useful for those who are interested in PCRs.

关键词： parallel continuum robots classification kinetostatic modeling performance evaluation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Aerodynamic optimization of an adaptive flap for next-generation green aircraft

引用

Chinese Journal of Aeronautics 2024年第2期37卷 100-122页

作者： Tianlong LIN Rosario PECORA Danilo CILIBERTI Wei XIA Shuling HU state key laboratory for Strength and vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China Deparment of Industrial Engineering Aerospace DivisionUniversity of Naples"FEDERICO II"Napoli 80125Italy

Adaptive,morphing flaps are taking ever-increasing attention in civil aviation thanks to the expected benefits this technology can bring at the aircraft level in terms of high-lift performance improvement and related fuel burnt reduction per *** upon morphing capabilities,it is possible to fix a unique setting for the flap and adapt the flap shape to match the aerodynamic requirements for take-off or *** proper morphed shapes can assure better high-lift performances than those achievable by referring to a conventional ***,standing the unique flap setting for take-off and landing,a dramatic simplification of the flap deployment systems may be *** a consequence of this simplification,the deployment system can be fully hosted in the wing,thus avoiding under-wing nacelles with significantly better aerodynamics and fuel *** first step for a rational design of an adaptive flap consists in defining the target morphed shapes and the unique optimal flap setting in the take-off and landing *** this work,aerodynamic optimization analyses are carried out to determine the best flap setting and related morphed shapes in compliance with the take-off and landing requirements of a reference civil transport *** different initial conditions are adopted to avoid the optimization falling into local optima,thus obtaining four groups of optimal candidate *** comparing each candidate’s performance through 2D and 3D simulations,the optimal configuration has been selected.2D simulations show that the optimal configuration is characterized by a maximum lift increase of 31.92%in take-off and 9.04%in *** to 3D simulations,the rise in maximum lift equals 22.26%in take-off and 3.50%in *** results are finally verified through wind tunnel tests,and the aerodynamic mechanism behind the obtained improvements is explained by carefully analyzing the flow field around the flap.

关键词： Morphing wings High-lift system Adaptive flap Computational Fluid Dynamics(CFD) Wind tunnel tests

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deployment analysis of composite thin-walled lenticular tubes with effect of storage time and temperature

引用

Chinese Journal of Aeronautics 2024年第1期37卷 162-172页

作者： Jinfeng DENG Ning AN Qilong JIA Xiaofei MA School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China state key laboratory for Strength and vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an 710049China state key laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Xi’an Institute of Space Radio Technology Xi’an 710100China

Composite Thin-walled Lenticular Tube(CTLT)is increasingly utilized in small satellites missions as a lightweight,foldable,and rollable structural material that facilitates the construction of large deployable *** CTLT is initially flattened and coiled around a central hub for storage before launch,during which elastic energy is stored as deformation energy,allowing it to be self-deployed on demand for use in *** work presents a comprehensive investigation into the coiling,storage and deployment behaviors of CTLT that wraps around a central hub.A nonlinear explicit dynamic finite element model was developed with both deformable CTLT and rigidbodies mechanisms including the central hub and guide rollers,as well as the complex interactions among *** coiling mechanics characteristics such as stored strain energy and rotational moment were presented and validated against experimental data in the ***,the dynamic deployment behaviors were analyzed in terms of two different deployment methods,namely,controlled deployment and free *** effect of material property change during storage was also discussed through numerical experiments.

关键词： Composite deployable structures Deployment dynamics Finite element method Stress relaxation Thin-walled booms

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical Simulation of the Seismic Response of a Horizontal Storage Tank Based on a SPH-FEM Coupling Method

引用

Computer Modeling in Engineering & Sciences 2024年第5期139卷 1655-1678页

作者： Peilei Yan Endong Guo HouliWu Liangchao Zhang key laboratory of Earthquake Engineering and Engineering vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin150080China key laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin150080China

A coupled numerical calculation method combining smooth particle hydrodynamics(SPH)and the finite element method(FEM)was implemented to investigate the seismic response of horizontal storage *** of a horizontal storage tank featuring a free liquid surface under seismic action was constructed using the SPH–FEM coupling *** stored liquid was discretized using SPH particles,while the tank and supports were discretized using the *** interaction between the stored liquid and the tank was simulated by using the meshless particle contact ***,the numerical simulation results were compared and analyzed against seismic simulation shaking table test data to validate the ***,a series of numerical models,considering different liquid storage volumes and seismic effects,were constructed to obtain time history data of base shear and top center displacement,which revealed the seismic performance of horizontal storage *** simulation results and experimental data showed good agreement,with an error rate of less than 18.85%.And this conformity signifies the rationality of the SPH-FEM coupling *** base shear and top center displacement values obtained by the coupled SPH-FEM method were only 53.3% to 69.1% of those calculated by the equivalent mass method employed in the current *** the stored liquid volume increased,the seismic response of the horizontal storage tank exhibited a gradual upward trend,with the seismic response increasing from 73% to 388% for every 35% increase in stored liquid *** maximum von Mises stress of the tank and the supports remained below the steel yield strength during the *** coupled SPH-FEM method holds certain advantages in studying the seismic problems of tanks with complex structural forms,particularly due to the representation of the flow field distribution during earthquakes by involving reservoir fluid participation.

关键词： SPH-FEM coupling method horizontal storage tank seismic response sloshing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Wall temperature effects on the stability of leeward vortices of a blunt inclined cone

引用

Acta Mechanica Sinica 2024年第7期40卷 29-42页

作者： Ligeng Zhang Bingbing Wan Siwei Dong Jianqiang Chen Xi Chen state key laboratory of Aerodynamics Mianyang 621000China

Streamwise vortex instability is one of the most potent mechanisms for the transition of the three-dimensional boundary *** using the global stability analysis methods,stability characteristics of the leeward vortex over a blunt cone with an angle of attack under a typical wind tunnel condition are studied and are compared to the case with a smaller wall temperature ratio(corresponding to a flight condition).The vortical structure features inward and outward vortices,similar to that in the flight *** the flight condition,the outward vortices appear stronger than the inward vortices,resulting in stronger outer-mode *** the inner mode is heavily stabilized compared to the flight condition,it can still radiate apparent *** acoustic sources are computed based on Lighthill's acoustic analogy,showing that the entropy term measuring the deviation from the isentropic relation is *** Mack second mode is shown to most likely trigger the transition in the flight condition,it is absent in the wind tunnel condition,and a shear-layer mode turns out to be the most dangerous ***,the instability frequencies and growth rates of the wind tunnel case are much smaller than those of the flight case,indicating that wall heating may stabilize the leeward vortices.

关键词： Instability of streamwise vortices Hypersonic boundary layer flow Spatial BiGlobal method PSE3D method

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Independent dual beams generated by array element division in integrated optical phased arrays

引用

Chinese Optics Letters 2024年第7期22卷 35-41页

作者： Guihan Wu Yu Xin Lemeng Leng Xiang Ji Shichong Yang Kaifei Tang Quan Luo Hongsheng Luo Jinshan Su Wei Jiang College of Engineering and Applied Sciences Nanjing UniversityNanjing 210023China National laboratory of Solid-state Microstructures Nanjing 210093China key laboratory of Intelligent Optical Sensing and Manipulation Ministry of EducationNanjing UniversityNanjing 210023China Jiangsu key laboratory of Artificial Functional Materials Nanjing UniversityNanjing 210023China key laboratory of vibration Signal Capture and Intelligent Processing Yili Normal UniversityIli 835000China

Optical phased arrays(OPAs)have broad application prospects due to their advanced capability in beamforming and *** this work,we achieve independent dual beams in the far field by dividing the array elements of the OPA,with the maximum scanning range reaching 100°.Based on the working principle of OPAs,theoretical considerations of such multibeam generation are presented.A phase data allocation approach for OPAs in the presence of fabrication-induced random phase variation is *** of large ensembles of OPAs with various levels of random residual phase errors have been conducted to help analyze the *** approach can help OPAs realize multi-beams for light detection and ranging(LiDAR).

关键词： optical phased arrays beamforming phase error calibration array element division.D01:10.3788/COL202422.071301

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimization of Band Gap of 1D Elastic Metamaterial Under Impact Load by Regulating Stiffness

引用

Acta Mechanica Solida Sinica 2024年第1期37卷 148-154页

作者： Tong Li Xianlong Jin Yongqiang Li Peizhong Yang School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China state key laboratory of Mechanical System and vibration Shanghai Jiaotong UniversityShanghai 200240China College of Science Northeastern UniversityShenyang 110819China

Designing materials that mitigate impacts effectively are crucial for protecting people and ***,a single-resonator metamaterial with negative mass characteristics is proposed for impact mitigation,and numerical analysis of wave propagation shows explicitly how the spring stiffness and number of unit cells influence that *** results show clearly that a metamaterial with differing microstructural stiffness is better at mitigating the effect of a shock wave than one with a unique ***,there is a critical number of unit cells beyond which the shock wave is not attenuated further,but the fabrication complexity *** the 40 groups of microstructural regions in this example,the attenuation effect no longer increases when there are more than 35 *** work offers guidance for microstructure designs in metamaterials and provides new ideas for using metamaterials to mitigate shock waves.

关键词： Elastic metamaterials Wave attenuation Stiffness Number of unit cells

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Experimental and numerical demonstration of hierarchical time-delay reservoir computing based on cascaded VCSELs with feedback and multiple injections

引用

Science China(Information Sciences) 2024年第2期67卷 279-290页

作者： Xingxing GUO Shuiying XIANG Xingyu CAO Biling GU state key laboratory of Integrated Service Networks Xidian University state key Discipline laboratory of Wide Bandgap Semiconductor Technology School of MicroelectronicsXidian University

In this paper, we propose and demonstrate experimentally and numerically a hierarchical timedelay optical reservoir computing(RC) system based on cascaded vertical-cavity surface-emitting lasers(VCSELs) with feedback and multiple injections. The prediction performance characteristics of the hierarchical time-delay RC system based on cascaded VCSELs under different reservoir layers are ***, the prediction performance of the hierarchical time-delay RC system is first improved and saturates as the number of reservoir layers increases. Besides, the impacts of key factors on predicting the hierarchical time-delay RC system are also analyzed in detail experimentally and numerically. This proposed hierarchical time-delay RC system based on VCSELs is useful for the further development of RC systems and may be beneficial to improve the ability of RC systems to solve more complex problems.

关键词： vertical-cavity surface-emitting laser reservoir computing neuromorphic photonics time-delay system information processing

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：