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Space-time evolution rules study on acoustic emission location in rock under cyclic loading
Jiang XU, Shuchun LI, Yunqi TAO, Yongdong JIANG, Xiaojun TANG,
《结构与土木工程前沿(英文)》 2009年 第3卷 第4期 页码 422-427 doi: 10.1007/s11709-009-0056-8
关键词: location result AE location consistent friction elastic-plastic deformation
Tahir MAHMOOD, Sangarapillai KANAPATHIPILLAI, Mahiuddin CHOWDHURY
《机械工程前沿(英文)》 2013年 第8卷 第2期 页码 181-186 doi: 10.1007/s11465-013-0257-7
This paper demonstrates the application of a new multiaxial creep damage model developed by authors using stress traixiality to predict the failure time of a component made of 0.5%Cr-0.5%Mo-0.25%V low alloy steel. The model employs strain energy density and assumes that the uniaxial strain energy density of a component can be easily calculated and can be converted to multi-axial strain energy density by multiplying it to a function of stress trixiality which is a ratio of mean stress to equivalent stress. For comparison, an elastic-creep and elastic-plastic-creep finite element analysis (FEA) is performed to get multi-axial strain energy density of the component which is compared with the calculated strain energy density for both cases. The verification and application of the model are demonstrated by applying it to thin tube for which the experimental data are available. The predicted failure times by the model are compared with the experimental results. The results show that the proposed model is capable of predicting failure times of the component made of the above-mentioned material with an accuracy of 4.0%.
关键词: elastic-creep elastic-plastic-creep stress triaxiality life prediction pressure vessels finite element analysis (FEA)
Subhash ANURAG, Yuebin GUO,
《机械工程前沿(英文)》 2010年 第5卷 第3期 页码 247-255 doi: 10.1007/s11465-010-0097-7
关键词: surface temperature friction residual stress finite element analysis (FEA) dry cutting tool property
Fatigue crack initiation of magnesium alloys under elastic stress amplitudes: A review
B. J. WANG, D. K. XU, S. D. WANG, E. H. HAN
《机械工程前沿(英文)》 2019年 第14卷 第1期 页码 113-127 doi: 10.1007/s11465-018-0482-1
关键词: Mg alloys fatigue behavior microstructure crack initiation deformation mechanism
An improved algorithm for McDowell’s analytical model of residual stress
null
《机械工程前沿(英文)》 2014年 第9卷 第2期 页码 150-155 doi: 10.1007/s11465-014-0295-9
The analytical model for two-dimensional elastoplastic rolling/sliding contact proposed by McDowell is an important tool for predicting residual stress in rolling/sliding processes. In application of the model, a problem of low predicting precision near the surface layer of the component is found. According to the volume-constancy of plastic deformation, an improved algorithm for McDowell’s model is proposed in order to improve its predicting accuracy of the surface residual stress. In the algorithm, a relationship between three normal stresses perpendicular to each other at any point within the component is derived, and the relationship is applied to McDowell’s model. Meanwhile, an unnecessary hypothesis proposed by McDowell can be eliminated to make the model more reasonable. The simulation results show that the surface residual stress predicted by modified method is much closer to the FEM results than the results predicted by McDowell’s model under the same simulation conditions.
关键词: residual stress McDowell’s model volume-constancy of plastic deformation FEM elastoplastic rolling/sliding contact
《结构与土木工程前沿(英文)》 2023年 第17卷 第5期 页码 763-779 doi: 10.1007/s11709-023-0917-6
关键词: underground structures precast sidewall specimen seismic test method bearing capacity energy dissipation capacity plastic deformation
Analysis on annealing-induced stress of blind-via TSV using FEM
Jie SHAO, Tielin SHI, Li DU, Lei SU, Xiangning LU, Guanglan LIAO
《机械工程前沿(英文)》 2018年 第13卷 第3期 页码 401-410 doi: 10.1007/s11465-017-0457-7
Copper-filled through silicon via (TSV) is a promising material owing to its application in high-density three-dimensional (3D) packaging. However, in TSV manufacturing, thermo-mechanical stress is induced during the annealing process, often causing reliability issues. In this paper, the finite element method is employed to investigate the impacts of via shape and SiO2 liner uniformity on the thermo-mechanical properties of copper-filled blind-via TSV after annealing. Top interface stress analysis on the TSV structure shows that the curvature of via openings releases stress concentration that leads to ~60 MPa decrease of normal stresses, sxx and syy, in copper and ~70 MPa decrease sxx of in silicon. Meanwhile, the vertical interface analysis shows that annealing-induced stress at the SiO2/Si interface depends heavily on SiO2 uniformity. By increasing the thickness of SiO2 linear, the stress at the vertical interface can be significantly reduced. Thus, process optimization to reduce the annealing-induced stress becomes feasible. The results of this study help us gain a better understanding of the thermo-mechanical behavior of the annealed TSV in 3D packaging.
关键词: through silicon via (TSV) annealing-induced stress interface stress plastic deformation finite element method
Moving policy and regulation forward for single-use plastic alternatives
《环境科学与工程前沿(英文)》 2021年 第15卷 第3期 doi: 10.1007/s11783-021-1423-5
关键词: Single-use plastic alternatives Policy Regulation Sustainable development
Nonlinear dynamic analysis for elastic robotic arms
M. H. KORAYEM, H. N. RAHIMI
《机械工程前沿(英文)》 2011年 第6卷 第2期 页码 219-228 doi: 10.1007/s11465-011-0218-y
The aim of the paper is to analyze the nonlinear dynamics of robotic arms with elastic links and joints. The main contribution of the paper is the comparative assessment of assumed modes and finite element methods as more convenient approaches for computing the nonlinear dynamic of robotic systems. Numerical simulations comprising both methods are carried out and results are discussed. Hence, advantages and disadvantages of each method are illustrated. Then, adding the joint flexibility to the system is dealt with and the obtained model is demonstrated. Finally, a brief description of the optimal motion generation is presented and the simulation is carried out to investigate the role of robot dynamic modeling in the control of robots.
关键词: robotic arms elastic link elastic joint nonlinear dynamics optimal control
Senping WANG; Xiaolong LIU; Bo YUAN; Minjie SHI; Yanhui WEI
《结构与土木工程前沿(英文)》 2022年 第16卷 第9期 页码 1141-1152 doi: 10.1007/s11709-022-0866-5
关键词: torsional stiffness strength design elastic buckling space truss arches out-of-plane
Effects of elastic support on the dynamic behaviors of the wind turbine drive train
Shuaishuai WANG, Caichao ZHU, Chaosheng SONG, Huali HAN
《机械工程前沿(英文)》 2017年 第12卷 第3期 页码 348-356 doi: 10.1007/s11465-017-0420-7
The reliability and service life of wind turbines are influenced by the complex loading applied on the hub, especially amidst a poor external wind environment. A three-point elastic support, which includes the main bearing and two torque arms, was considered in this study. Based on the flexibilities of the planet carrier and the housing, a coupled dynamic model was developed for a wind turbine drive train. Then, the dynamic behaviors of the drive train for different elastic support parameters were computed and analyzed. Frequency response functions were used to examine how different elastic support parameters influence the dynamic behaviors of the drive train. Results showed that the elastic support parameters considerably influenced the dynamic behaviors of the wind turbine drive train. A large support stiffness of the torque arms decreased the dynamic response of the planet carrier and the main bearing, whereas a large support stiffness of the main bearing decreased the dynamic response of planet carrier while increasing that of the main bearing. The findings of this study provide the foundation for optimizing the elastic support stiffness of the wind turbine drive train.
关键词: wind turbine drive train elastic support dynamic behavior frequency response function
Frequencies of circular plate with concentric ring and elastic edge support
null
《机械工程前沿(英文)》 2014年 第9卷 第2期 页码 168-176 doi: 10.1007/s11465-014-0299-5
Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considered circular plate are computed for different sets of values of elastic rotational and translation restraints and the radius of internal rigid ring support. The results for the first three modes of plate vibrations are computed and are presented in tabular form. The effects of rotational and linear restraints and the radius of the rigid ring support on the vibration behavior of circular plates are studied over a wide range of non-dimensional parametric values. The values of the exact frequency parameter presented in this paper for varying values of restraint parameters and the radius of the rigid ring support can better serve in design and as benchmark solutions to validate the numerical methods obtained by using other methods of solution.
关键词: circular plate frequency elastic edge rigid ring mode switching
《环境科学与工程前沿(英文)》 2023年 第17卷 第6期 doi: 10.1007/s11783-023-1666-4
● A global snapshot of plastic waste generation and disposal is analysed.
关键词: Plastic waste Farmlands Terrestrial ecosystem Marine life
郑颖人,孔亮
《中国工程科学》 2005年 第7卷 第11期 页码 21-36
分析了经典塑性力学用于岩土类材料的问题,它采用了3个不符合岩土材料变形机制的假设。从固体力学原理直接导出广义塑性位势理论,将经典塑性力学改造为更一般的塑性力学——广义塑性力学。广义塑性力学采用了塑性力学中的分量理论,能反映应力路径转折的影响,并避免了采用正交流动法则所引起的过大剪胀等不合理现象,也不会产生当前非关联流动法则中任意假定塑性势面引起的误差。给出了广义塑性力学的屈服面理论、硬化定律和应力-应变关系,并建立了考虑应力主轴旋转的广义塑性位势理论。屈服条件是状态参数,也是试验参数,只能由试验给出。应用表明,广义塑性力学可作为岩土材料的建模理论,还可应用于诸如极限分析等土力学的诸多领域,具有广阔的应用前景。
Resistance of large deformation of the Wushaoling Tunnel F7 soft fault
ZHAO Xufeng, CHEN Haiming, WANG Chunmiao
《结构与土木工程前沿(英文)》 2007年 第1卷 第1期 页码 123-127 doi: 10.1007/s11709-007-0013-3
标题 作者 时间 类型 操作
Space-time evolution rules study on acoustic emission location in rock under cyclic loading
Jiang XU, Shuchun LI, Yunqi TAO, Yongdong JIANG, Xiaojun TANG,
期刊论文
using strain energy density as a function of stress triaxiality under quasi-static loading employing elastic-creep& elastic-plastic-creep deformation
Tahir MAHMOOD, Sangarapillai KANAPATHIPILLAI, Mahiuddin CHOWDHURY
期刊论文
Predictive model to decouple the contributions of friction and plastic deformation to machined surface
Subhash ANURAG, Yuebin GUO,
期刊论文
Fatigue crack initiation of magnesium alloys under elastic stress amplitudes: A review
B. J. WANG, D. K. XU, S. D. WANG, E. H. HAN
期刊论文
Effect of strata restraint on seismic performance of prefabricated sidewall joints in fabricated subway stations
期刊论文
Analysis on annealing-induced stress of blind-via TSV using FEM
Jie SHAO, Tielin SHI, Li DU, Lei SU, Xiangning LU, Guanglan LIAO
期刊论文
Out-of-plane elastic buckling load and strength design of space truss arch with a rectangular section
Senping WANG; Xiaolong LIU; Bo YUAN; Minjie SHI; Yanhui WEI
期刊论文
Effects of elastic support on the dynamic behaviors of the wind turbine drive train
Shuaishuai WANG, Caichao ZHU, Chaosheng SONG, Huali HAN
期刊论文
Current scenario and challenges of plastic pollution in Bangladesh: a focus on farmlands and terrestrial
期刊论文