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Stress fields caused by a dislocation in an anisotropic 3-layer system

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Science China(Physics,Mechanics & Astronomy) 2011年第3期54卷 542-551页

作者： WANG HuYi yin yihui YU ShaoRong Institute of Structural Mechanics China Academy of Engineering Physics Mianyang 621900 China

We investigated the stress fields caused by a dislocation in an anisotropic 3-layer system. Based on the image method, the original 3-layer system is firstly decomposed into three infinite homogenous systems. The image dislocation densities used as unknowns are then strategically distributed in order to satisfy the boundary conditions. The resulting governing equations are singular Cauchy integral ones. Removing the singular terms yields non-linear Fredhom integral equations of the second kind. The obtained stress fields satisfy the boundary conditions, i.e., the traction free condition on the free surface and continuous conditions across the interfaces. Also, a comparison with previous results is made and good agreement is achieved. Numerical investigations show that under the plain strain condition, layer thickness and dislocation position play stronger roles in the stress fields than crystallographic orientation, and these effects more significantly affect the stress fields caused by an edge dislocation than by a screw dislocation.

关键词： stress field dislocation anisotropic 3-layer system

Research into tritium and helium-3 contents distributions in steel wall of spherical pressure vessel

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Science China(Technological Sciences) 2011年第6期54卷 1521-1524页

作者： LIU YuanDong yin yihui TAN Yun SUN yin MEI Jun Institute of Structural Mechanics China Academy of Engineering Physics P. O. Box 919-401 Mianyang 621900 China Committee of Science and Technology China Academy of Engineering Physics Mianyang 621900 China

The tritium quantity stored in a steel pressure vessel decreases with time because of helium-3 decay and permeation of tritium into the steel wall of the pressure ***,the tritium quantity permeating into the steel wall also decreases with time due to helium-3 decay and diffusion in and out of the wall of *** and helium-3 in the steel wall will cause hydrogen and helium embrittlement of the wall material,respectively,and thereby change the carrying capacity of the *** contemporarily both decay and permeation of tritium within the vessel and decay and diffusion of tritium having permeated into the wall into consideration,the governing equations of tritium and helium-3 contents in the wall were established and solved,and relevant formulas were *** analytical calculations,curves of tritium and helium-3 contents versus radius and time were theoretically plotted,the contents spatio-temporal distributions laws were obtained,and a law about helium-3 contents distribution in steel wall of a spherical pressure vessel was discovered which was called the law of double helium-3 content.

关键词： steel spherical pressure vessel tritium decay helium-3 diffusion law of double helium-3 content

The relationship between indoor air quality(IAQ)and perceived air quality(PAQ)-a review and case analysis of Chinese residential environment

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Energy and Built Environment 2024年第2期5卷 230-243页

作者： Jingjing Pei Meinan Qu Luyao Sun Xueyong Wang yihui yin Tianjin Key Laboratory of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityTianjin 300072China

Due to the majority of time people spent indoors,indoor air quality is not only critical to people’s health,comfort,but can also significantly influence occupants perception on indoor *** quality is closely related to many factors including thermal parameters,pollutant concentrations,and ventilation ***,the current building indoor air quality evaluation method is based the objective measurement of indoor parameters,without considering occupants’subjective *** paper is aimed at summarizing a profound review on the PAQ evaluation *** among various PAQ evaluating methods with advantages,similarities and differences were *** of literatures about indoor air quality in Chinese residential buildings field is also summarized,and discussion on the subjective influence of temperature and relative humidity,venti-lation performance,volatile organic compounds(VOCs)concentration,and particulate matters on perceived air quality is carried out.

关键词： Perceived air quality Temperature and relative humidity Volatile organic compound Ventilation Particulate matter

Static and dynamic design based on hierarchical optimization for materials and structure of porous metals

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Science China(Technological Sciences) 2012年第10期55卷 2808-2814页

作者： LIU YuanDong yin yihui GUO ZhongZe Institute of Structural Mechanics CAEPP.O.Box 919-401Mianyang 621900China

A static and dynamic collaborative optimization method for materials and structure with uniform periodic microstructure is *** sensitivity formulae of hierarchical optimization,i.e.,material design,structure design and integrated design for porous metals,are *** the base of the hierarchical optimization model,numerical experiments of an MBB beam and a cantilever one were carried *** on porous metals bearing multi-functionality,the differences and applicability of hierarchical optimization are discussed in the structure loading *** is concluded that structure design is mainly oriented to structure efficiency,material design is mainly oriented to multi-functionality,and integrated design is oriented to structure efficiency and *** work provides some useful ideas for the selection of porous metals design method.

关键词： porous metals multi-objectives hierarchical optimization material design structure design integrated design of materials and structure

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螺栓啮合螺纹段的轴力、等效应力分布及摩擦的影响分析

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机械强度 2006年第4期28卷 524-531页

作者：尹益辉余绍蓉中国工程物理研究院结构力学研究所四川绵阳621900

采用有限元数值模拟方法,考虑螺栓材料的弹塑性性质,计算分析普通三角形螺纹螺栓—螺母副在轴向力作用下的内力、应力和变形规律。给出不同总轴力下螺栓螺纹段中轴向力和螺牙根部最大等效应力沿轴向的非线性分布规律和总轴力在各圈螺纹... 详细信息

采用有限元数值模拟方法,考虑螺栓材料的弹塑性性质,计算分析普通三角形螺纹螺栓—螺母副在轴向力作用下的内力、应力和变形规律。给出不同总轴力下螺栓螺纹段中轴向力和螺牙根部最大等效应力沿轴向的非线性分布规律和总轴力在各圈螺纹上的分配关系;对由轴对称二维螺牙模型、三维回转螺牙模型和三维螺旋线型螺牙模型计算得到的对应各圈螺纹上的轴向力和螺牙根部最大等效应力进行比较,指出在工程分析中,对于轴向载荷作用情况,可近似将螺旋线型螺牙简化为三维回转螺牙;给出螺栓绕轴线的转角和各圈螺纹上传递的轴向力随螺牙界面摩擦因数的非线性变化规律,得出轴向外力下螺纹段最大等效应力随摩擦因数增大而减小的规律。

关键词：螺栓连接结构三维有限元分析摩擦变形弹塑性应力

基于3D有限元模拟的螺栓接头变形—内力关系及在设计中的应用

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机械强度 2008年第6期30卷 947-952页

作者：尹益辉余绍蓉中国工程物理研究院总体工程研究所四川绵阳621900

考虑螺纹的三维螺旋线形几何特征和各组件结合面之间的摩擦接触关系,利用***软件建立螺纹螺栓—被连接件组合结构(接头)的三维接触有限元模型,并进行计算,给出接头轴向力与轴向变形之间的非线性关系曲线、残余预紧力和螺纹段最大等效应... 详细信息

考虑螺纹的三维螺旋线形几何特征和各组件结合面之间的摩擦接触关系,利用***软件建立螺纹螺栓—被连接件组合结构(接头)的三维接触有限元模型,并进行计算,给出接头轴向力与轴向变形之间的非线性关系曲线、残余预紧力和螺纹段最大等效应力随被连接件所受轴向外力的非线性变化关系曲线。分析这些非线性曲线的规律,得到相应的结论。基于这些曲线,提出确定螺栓接头预紧力和允许外力的方法。

关键词：螺纹螺栓三维接触有限元法变形应力设计方法

点缺陷类型和浓度对α-Fe塑性变形行为影响的分子动力学模拟

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稀有金属材料与工程 2022年第8期51卷 2881-2891页

作者：李翔尹益辉张元章中国工程物理研究院总体工程研究所四川绵阳621999 西南科技大学应用技术学院四川绵阳621010

为了深入认识点缺陷对α-Fe塑性变形行为的影响,建立含点缺陷的α-Fe试样计算模型,以点缺陷的原子浓度为变量,开展试样单轴拉伸的分子动力学模拟。研究结果表明:在相同的缺陷浓度下,不同类型的点缺陷导致的晶格畸变程度不同,因而试样发... 详细信息

为了深入认识点缺陷对α-Fe塑性变形行为的影响,建立含点缺陷的α-Fe试样计算模型,以点缺陷的原子浓度为变量,开展试样单轴拉伸的分子动力学模拟。研究结果表明:在相同的缺陷浓度下,不同类型的点缺陷导致的晶格畸变程度不同,因而试样发生塑性变形的难易程度就不同,其中自间隙Fe原子导致的晶格畸变程度比空位大,相应试样更容易发生塑性变形;试样的塑性变形机制随点缺陷类型和浓度而变化,进而使试样的应力-应变曲线特征发生显著变化;对于本模拟中各浓度含空位的试样,或含较低浓度自间隙Fe原子或Frenkel缺陷的试样,塑性变形表现为拉伸应力诱发的相变和位错滑移混合的机制;对于含较高浓度自间隙Fe原子或Frenkel缺陷的试样,塑性变形以位错滑移和非晶化塑性变形为主且伴随有相变。本研究加深了有关点缺陷对金属变形机制影响的认识,为后续分析多晶α-Fe材料的物理和力学性质奠定了有益的基础。

关键词： α-Fe 点缺陷相变非晶化塑性变形

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楔环连接结构两种有限元优化设计方案研究

机械工程学报 2006年第8期42卷 205-209页

作者：黄鹏尹益辉莫军中国工程物理研究院总体工程研究所绵阳621900

利用APDL语言对ANSYS软件进行二次开发,建立楔环连接结构的参数化有限元模型。为了对该结构进行优化设计,以楔环径向和轴向尺寸为设计变量,以结构最大应力比为目标函数设计结构的增强优化方案,以结构的各件应力比差的平方和为目标函数... 详细信息

利用APDL语言对ANSYS软件进行二次开发,建立楔环连接结构的参数化有限元模型。为了对该结构进行优化设计,以楔环径向和轴向尺寸为设计变量,以结构最大应力比为目标函数设计结构的增强优化方案,以结构的各件应力比差的平方和为目标函数设计结构的等强设计方案。采用基于共轭梯度法的一阶优化方法求解,增强优化的结果表明,拉伸载荷下结构的最大等效应力降低21.1％,安全系数由1.08提高到1.37,可达到增强设计目的；等强优化的结果表明,优化后结构各件应力比接近,应力比差的平方和从0.600降为0.067,可以达到等强设计目的。实践说明采用非线性有限元法和一阶优化法对连接结构进行优化能够取得预想的效果。

关键词：楔环连接结构有限元模型优化设计共轭梯度法

Ultra-thin Body Buried In0.35Ga0.65As Channel MOSFETs with Extremely Low Off-current on Si Substrates

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Chinese Journal of Electronics 2021年第6期30卷 1017-1021页

作者： WANG Bo DING Peng FENG Ruize WANG Yanfu LIU Xiaoyu SUN Tangyou CHEN Yonghe LIU Xingpeng LI Qi LI Yue LIU yingbo yin yihui ZHAO Hao ZHANG Wei LI Haiou JIN Zhi Guangxi Key Laboratory of Precision Navigation Technology and Application Guilin University of Electronic Technology High-Frequency High-Voltage Device and Integrated Circuits Center Institute of MicroelectronicsChinese Academy of Sciences The 34th Research Institute of China Electronics Technology Group Corporation State Key Laboratory of ASIC & System Fudan University

In this paper, we investigated the electrical properties of the Metal-oxide-semiconductor gate stack of Ti/AlO/In P under different annealing conditions. A minimum interface trap density of 3×10cmeVis obtained without postmetallization annealing ***, utilizing Ti/AlO/In P MOS gate stack,we fabricated ultra-thin body buried In0.35 Ga0.65 As channel MOSFETs on Si substrates with optimized on/off trade-off. The 200 nm gate length device with extremely low off-current of 0.6 n A/μm, and on-off ratio of 3.3×10, is demonstrated by employing buried low indium(InGaAs) channel with In P barrier/spacer device structure, giving strong potential for future highperformance and low-power applications.

关键词： silicon gallium arsenide Si substrates size 200.0 nm minimum interface trap density III-V semiconductors As extremely low off-current postmetallization annealing treatment Si Ga In ultra-thin body optimized on-off trade-off MOSFET metal-oxide-semiconductor gate stack InP barrier-spacer device structure annealing elemental semiconductors O aluminium compounds different annealing conditions ultra-thin body buried channel MOSFET Ti-Al indium compounds interface states gate length device -InP