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An improved algorithm for McDowell’s analytical model of residual stress
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《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
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
王靖涛
《中国工程科学》 2006年 第8卷 第9期 页码 24-29
对岩土塑性变形过程中体应变与剪应变的相互作用原理的内涵做了深入的阐述,特别对塑性体应变和剪应变之间的相互作用方式,塑性体应变对抗剪能力的直接控制作用,剪缩和剪胀发生的条件,应力路径相关性是这种相互作用的综合体现及实例验证,临界状态是塑性和弹性体应变都保持不变的纯粹剪切变形过程等方面进行了论证;根据这个相互作用原理,在理论上证明了空间临界状态线的存在性和唯一性以及它与应力是无关的。
关键词: 岩土塑性体变形和剪应变的相互作用原理 岩土本构关系 压硬性 剪胀性
《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
Assessment of liver volume variation to evaluate liver function
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《医学前沿(英文)》 2012年 第6卷 第4期 页码 421-427 doi: 10.1007/s11684-012-0223-5
In order to assess the value of liver volumetry in cirrhosis and acute liver failure (ALF) patients, we explored the correlation between hepatic volume and severity of the hepatic diseases. The clinical data of 48 cirrhosis patients with 60 normal controls and 39 ALF patients were collected. Computed tomography-derived liver volume (CTLV) and body surface area (BSA) of normal controls were calculated to get a regression formula for standard liver volume (SLV) and BSA. Then CTLV and SLV of all patients were calculated and grouped by Child-Turcotte-Pugh classification for cirrhosis patients and assigned according to prognosis of ALF patients for further comparison. It turned out that the mean liver volume of the control group was 1 058±337 cm3. SLV was correlated with BSA according to the regression formula. The hepatic volume of cirrhosis patients in Child A, B level was not reduced, but in Child C level it was significantly reduced with the lowest liver volume index (CTLV/SLV). Likewise, in the death group of ALF patients, the volume index was significantly lower than that of the survival group. Based on volumetric study, we proposed an ROC (receiver operating characteristic) analysis to predict the prognosis of ALF patients that CTLV/SLV<83.9% indicates a poor prognosis. In conclusion, the CTLV/SLV ratio, which reflects liver volume variations, correlates well with the liver function and progression of cirrhosis and ALF. It is also a very useful marker for predicting the prognosis of ALF.
关键词: liver volume variation cirrhosis acute liver failure (ALF)
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
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
Destructive and non-destructive evaluation of concrete for optimum sand to aggregate volume ratio
《结构与土木工程前沿(英文)》 2021年 第15卷 第6期 页码 1400-1414 doi: 10.1007/s11709-021-0779-8
关键词: aggregates non-destructive testing sand-to-aggregate volume ratio (s/a) maximum aggregate size (MAS)
《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
Numerical modeling of nonlinear deformation of polymer composites based on hyperelastic constitutive
Qingsheng YANG, Fang XU
《机械工程前沿(英文)》 2009年 第4卷 第3期 页码 284-288 doi: 10.1007/s11465-009-0067-0
关键词: composites hyperelastic finite deformation homogenization micromechanics
《结构与土木工程前沿(英文)》 2022年 第16卷 第1期 页码 86-98 doi: 10.1007/s11709-021-0793-x
关键词: plastic concrete sulfate resistance natural zeolite triaxial compression test SEM permeability
Preventing masks from becoming the next plastic problem
《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1413-7
标题 作者 时间 类型 操作
Predictive model to decouple the contributions of friction and plastic deformation to machined surface
Subhash ANURAG, Yuebin GUO,
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
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
Destructive and non-destructive evaluation of concrete for optimum sand to aggregate volume ratio
期刊论文
Current scenario and challenges of plastic pollution in Bangladesh: a focus on farmlands and terrestrial
期刊论文
Resistance of large deformation of the Wushaoling Tunnel F7 soft fault
ZHAO Xufeng, CHEN Haiming, WANG Chunmiao
期刊论文
Numerical modeling of nonlinear deformation of polymer composites based on hyperelastic constitutive
Qingsheng YANG, Fang XU
期刊论文
Effects of natural zeolite and sulfate ions on the mechanical properties and microstructure of plastic
期刊论文