M30螺栓应力集中的应变电测

本文介绍了用应变电测法测试起重机上M30螺栓应力集中的一种方案.在现场实测时得到一系列测试数据和曲线,为分析该螺栓的疲劳破坏提供了依据.     

电测法确定压力容器角变形及错边处附加弯曲应力

本文根据内压容器的电测应力，研究了电测法确定角变形及错边处附力。弯曲应力的原理及方法，用此法可将弯曲应力从组合应力中分离出来，从而得到被测部位附加弯曲应力分布曲线，并由此给出残余应力限值，为工程技术人员采取相应措施改善这种部位的应力状况提供科学依据。     

第五讲 特殊条件下应变电测技术

在研究结构强度时,往往需要在特殊环境下测定构件的应变状态,在这方面,应变电测技术是现有实验应力分析方法中最有效的一种。但是,应变电测技术现已达到何种水平,在各种特殊环境下,应采取那些技术措施,以及其存在问题和发展趋势,本讲针对这些问题作一扼要介绍。     

相位修正技术及其在大型结构现场动力测试中的应用

本文介绍了相位修正技术、A/D板随动前置放大技术、及其在大型结构现场动力测试分析中的应用.相位修正技术解决了A/D板因轮换采样的时间差引起的频域相位差问题;而随动前置放大技术则解决了实测过程中各测点信噪比悬殊时带来的问题.这些技术的实现,使得以微机为基础的直接现场采样动力分析成为可能.最后的两个实际现场测试分析例子,证明了上述技术在工程实用中的可行性与可靠性.     

表面涂层材料的残余应力测量技术

本文采用电测盲孔法测定表面涂层材料残余应力的测量技术，在试件和表面涂层结构上进行测试．大量试验表明，此方法可靠、有效，可在工程实际中使用，为解决表面涂层“爆裂”等问题，提供了有效的测定残余应力的手段     

中国力学学会1983年学术活动计划

序号项目名称第2届亚洲流体力学大会国际ICF断裂力学会议第3届全国激波管学术会议4 l现场岩体观测及测试技术讨论会5 i地球动力学中岩石力学性质学术l讨论会理统计及概率分析在土工中的应用学习班全国生物固体力学讨论会电测实验技术讨论会动态光弹讨论会测、电测实验数据自动采集及处技术讨论会物理化学流体力学学习班气液两相流学习班电测培训班’呼吸系统动力学讨论班爆破安全技术讨论会复合材料力学专题讨论会.分叉、突变,?...      

材料力学实验教学改革实践与探讨

 介绍了材料力学组合变形电测实验教学改革的实践. 采用现代 测试技术，结合工程实际，更新实验内容，形成了新的电测综合型实 验.     

复合结构壳体蠕变变形有限元研究

基于蠕变理论，采用有限元数值计算方法，用ANSYS作为计算平台，建立了壳体结构的蠕变变形计算模型．对由耐火材料是镁碳砖炉衬和炉壳组成的复合结构转炉，由于高导热率的镁碳砖广泛使用，引起转炉炉壳的温度升高，导致转炉不同程度地出现了炉壳蠕变变形，致使炉壳使用寿命缩短．研究转炉炉壳蠕变变形的状态及分布规律，可为控制炉壳蠕变变形、延长炉壳使用寿命提供依据．运用所述的有限元计算模型，对复合结构的转炉炉壳的蠕变变形行为进行模拟，模拟结果与现场测量值基本吻合．     

电测技术的研究现状与展望

本文论述电测技术在经济建设中的地位和作用,阐述检测元件、电测微机系统和恶劣环境下电测技术的发展现状以及电测技术在新学科发展中的作用,指出了电测技术今后的发展前景。     

用白光相对客观散斑技术实测海冰力学性质的初探

本文提出了一种改进的白光散技术，应用此技术测量了单轴压缩下海冰的弹性模量，实测结果与电测法的结果符合程度良好，本文方法操作简单，避免了海水的表面缺隐和浸反射条件差以及表面升华等因素对测量的影响。     

一种基于直接计算高阶奇异积分的断裂力学双边界积分方程分析法

相对于有限元法,边界单元法在求解断裂问题上有着独特的优势,现有的边界单元法中主要有子区域法和双边界积分方程法.采用一种改进的双边界积分方程法求解二维、三维断裂问题的应力强度因子,对非裂纹边界采用传统的位移边界积分方程,只需对裂纹面中的一面采用面力边界积分方程,并以裂纹间断位移为未知量直接用于计算应力强度因子.采用一种高阶奇异积分的直接法计算面力边界积分方程中的超强奇异积分;对于裂纹尖端单元,提供了三种不同形式的间断位移插值函数,采用两点公式计算应力强度因子.给出了多个具体的算例,与现存的精确解或参考解对比,可得到高精度的计算结果.      

汶川地震诱发文家沟巨型滑坡 碎屑流基本特征及成因机制初步分析

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2008年5月12日,汶川M80地震在四川省绵竹市清平乡文家沟内诱发一巨型滑坡。通过现场调查得知,滑坡前后缘高差455m,厚度20～30m,滑面为基岩层面,初始方量2750×107m3。滑体在运动中转化为碎屑流。滑坡-碎屑流总的水平运动距离为4022m,垂直运动距离为1443m,遗留的堆积物体积达5×107m3。滑坡距映秀—北川断裂仅36km,位于其下盘,地震烈度达XI度。滑坡导致文家沟中48人遇害,并形成一条完整的地震次生地质灾害链。初步分析表明滑坡启动速度快,滑坡向碎屑流转化过程明显、地点明确。碎屑流运动过程复杂,伴有强烈的“气垫效应”和“前缘气浪冲击效应”。作者认为,文家沟滑坡的高启动速度是长持时强烈地震动作用的结果,与山体的猛烈碰撞是导致滑体解体并转化为碎屑流的原因。     

Preface: Orbits around asteroid

One of the core issues in modern celestial mechanics is the orbital dynamics in the near-regime gravitational field of as- teroids, which provides deep insights into the mathematical nature of a class of nonlinear systems, and plays as a critical basis for in situ explorations of different science goals. Lots of efforts have been made to reveal the characteristics of orbital motion in the vicinity of asteroids, and to improve the skills of asteroid research in methodology.     

Effet de l'anisotropie élastique cristalline sur la distribution des facteurs de Schmid à la surface des polycristauxInfluence of crystalline elasticity anisotropy on Schmid factor distribution at the free surface of polycrystals

Experimental studies of the plasticity mechanisms of polycrystals are usually based on the Schmid factor distribution supposing crystalline elasticity isotropy. A numerical evaluation of the effect of crystalline elasticity anisotropy on the apparent Schmid factor distribution at the free surface of polycrystals is presented. Cubic elasticity is considered. Order II stresses (averaged on all grains with the same crystallographic orientation) as well as variations between averages computed on grains with the same crystallographic orientation but with different neighbour grains are computed. The Finite Element Method is used. Commonly studied metals presenting an increasing anisotropy degree are considered (aluminium, nickel, austenite, copper). Concerning order II stresses in strongly anisotropic metals, the apparent Schmid factor distribution is drifted towards small Schmid factor values (the maximum Schmid factor is equal to 0.43 instead of 0.5) and the slip activation order between characteristic orientations of the crystallographic standard triangle is modified. The computed square deviations of the stresses averaged on grains with the same crystallographic orientation but with different neighbour grains are a bit higher than the second order ones (inter-orientation scatter). Our numerical evaluations agree quantitatively with several observations and measures of the literature concerning stress and strain distribution in copper and austenite polycrystals submitted to low amplitude loadings. Hopefully, the given apparent Schmid factor distributions could help to better understand the observations of the plasticity mechanisms taking place at the free surface of polycrystals. To cite this article: M. Sauzay, C. R. Mecanique 334 (2006).     

Nonlinear behavior of matrix-inclusion composites under high confining pressure: application to concrete and mortar

This paper is devoted to a micromechanics-based simulation of the response of concrete to hydrostatic and oedometric compressions. Concrete is described as a composite made up of a cement matrix in which rigid inclusions are embedded. The focus is put on the role of the interface between matrix and inclusion which represent the interfacial transition zone (ITZ). A plastic behavior is considered for both the matrix and the interfaces. The effective response of the composite is derived from the modified secant method adapted to the situation of imperfect interfaces. To cite this article: T.H. Le et al., C. R. Mecanique 336 (2008).     

Dynamics and Breakup of Viscoelastic Liquids (A Review)

The phenomena of hydrodynamic breakup of liquid jets, drops, films, bridges, and filaments are reviewed for liquids with viscoelastic properties. The reasons for breakup are capillary instabilities, collisions with rigid obstacles, and other forms of dynamic action. The relationship between the properties of the liquids and the features of the breakup process is discussed.     

Flow stability analysis and excitation using pulsating jets

Classical flow stability applied to transition from laminar to turbulent flow may also describe the behavior of vorticity fluctuations created by a pulsating jet placed along a solid boundary. A numerical laminar flow experiment involving a pulsating jet placed along the surface of a duct with flow separation downstream, resulted in eliminating most part of the separated flow region. Applying the same approach to a turbulent flow, it was possible to develop a turbulent stability flow formulation and apply successfully turbulent pulsating jet flow separation control. To cite this article: D. Skamnakis, K. Papailiou, C. R. Mecanique 333 (2005).