查询词典 strain theory

The main factors affecting the soil-structure interface behaviors were found experimentally and theoretically, including: 1 the thickness of the interface that is five to six times the average grain size of the soil; 2 the aeolotropy of interface, which is responsible for anisotropic response of the stress-strain response of the interface; 3 two physical states, including crashing and compression of the soil near the structure surface, which govern the stress-strain response of the interface strongly; 4 two shear deformation components due to sliding and constraint of the structure surface relative to the soil respectively, which forms the deformation of the interface; 5 the volumetric strain due to dilatancy, which is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. 4. A unified constitutive model of the interface, based on new elasto-plasticity damage theory, was developed. It was confirmed to be effective for the conditions considering monotonic and cyclic shearing, coupling effect of shear and volumetric strains, evolution of physical state, micro-structure aeolotropy of the soil and the resulting aeolotropy of the interface as well as the three normal boundary conditions stated above. 5. 2D and 3D finite element formulations of the present model were derived and incorporated into the FEM codes. They were applied to the evaluation of practical engineering problems with different typical interfaces between soil and structure. The new model was shown to be reasonable and effective.

确定了粗粒土与结构接触面厚度约为5～6倍的平均粒径，首次揭示了接触面的细观结构异向性以及由此所引起的宏观剪切异向性，发现了在单调和往返剪切荷载作用下土颗粒破碎和剪切压密两种物态变化机制共同支配着接触面力学性质的变化，通过细观分析证实了接触面的变形可分解为一般同时发生的土与结构交界面上的滑移变形以及结构面位移约束范围之内土体本身的剪切变形两部分，观测到接触面受剪时表现出明显的相对法向位移，并可分解为可逆性和不可逆性两个分量；(4)建立了第一个能够统一地描述单调与往返剪切特性、剪应变与体应变耦合特性、细观结构和宏观剪切异向性以及土颗粒破碎等物态变化特性的土与结构接触面弹塑性损伤本构数学模型，并采用多种法向边界条件复杂加载路径的试验成果验证了新模型的合理性和有效性；(5)提出了新模型的二、三维有限元格式并结合实际边值问题进行了应用计算分析，比较了不同接触面本构模型对计算结果的影响，证实了新模型及其有限元格式不仅能够合理地描述土与结构接触面的主要力学特性，还能够较好地反映土体与结构物在接触面处的滑移、脱开等不连续现象。

The fatigue is analyzed for the SENT specimen of TA6V titanium alloy at different stress ratio and on different stress level by the general finite element analysis software ANSYS. The dangerous fatigue location is predicted by the nodal stress Y-direction of the hemicycle notch for TA6V titanium alloy SENT specimen. Based on the local stress-strain method and the material S-N graph, the nominal stress-strain of the specimen is converted to the local stress-strain of the dangerous location by the elastic and plastic finite element analysis, thus the fatigue life is estimated by Miner fatigue damage accumulation theory and compared with the fatigue test of small crack growth.

借助大型通用有限元分析软件ANSYS对TA6V钛合金SENT试样在不同应力比和不同应力水平下进行疲劳分析，根据SENT试样缺口处的应力状态分布预测疲劳危险部位，采用局部应力应变法，结合材料循环的S-N曲线，通过弹塑性有限元法将构件上的名义应力谱转换成危险部位的局部应力应变谱，从而根据危险部位的局部应力应变历程采用Miner累积损伤理论对构件的疲劳寿命进行估算，并与疲劳小裂纹试验数据进行比较分析。

K. H. Roscoe and his fellows of Cambridge University established the first elastoplastic model of soils which is based on classical plastic theory in 1963. However, due to the complexity of soils, the models that based on the classical metal constitutive theory or its modification accounting on the nature of soils have still much limitation when used to express the soil mechanical behavior. For example, the Duncan-Chang's model based on the generalized Hooke's law can not express the dilatancy of the soils. The uniqueness assumption of the direction of the incremental plastic strain in the classical plastic constitutive theory is not in agreement with some soil experiments.

但由于土的复杂性，目前以传统的本构理论为基础考虑土的一些特性而建立的模型在反映土体的力学特性上还存在很大的局限性，如建立于广义虎克定律基础上的Duncan—Chang模型不能反映土的剪胀性，传统的塑性本构理论中认为塑性应变增量方向具有唯一性的假设与一些土体的试验结果不符合。

The stress amplitude and aging time of single serration varies with temperature, strain rate and strain, which tend to be in accordance with the dynamic strain aging theory.

单个锯齿的应力幅度和时效时间随温度、应变速率和应变量的变化基本符合动态应变时效的理论。

This paper discusses the yield function, loading unloading criterion and constitutive equation of Lagrangian finite deformation elastic-plasticity theory. Finally, Lagrangian finite elastic plasticity theory is used on constitutive models of elastic-plasticity at infinitesimal strain, and the complete constitutive relation for singular yield surface theory is obtained.

本文讨论了Lagrange型有限变形弹塑性本构理论的屈服函数、加卸载准则、本构方程等，最终将Lagrange型有限变形弹塑性本构理论应用于小变形情况下的奇异屈服面弹塑性模型，得出了完整的Lagrange型有限变形弹塑性本构理论。

In the second part, the theory of numerical simulation is introduced, including description of body configuration, elastic-plastic large deformation constitutive equation and finite element formula. It is followed by the derivation of equation from the basic theory of elastic-plastic deformation. The solution to temperature field, thermal stress, thermal strain, equivalent effective stress and equivalent strain is achieved then. In addition, we exposit the relation between machine load and thermal load in coupling analysis.

介绍了物体的构形及其描述，弹塑性大变形的本构方程、有限元列式；并进一步论述了弹塑性变形的基本理论，推导了弹塑性方程组；阐述了温度场的求解、热应力及热应变的理论概要，说明了等效应力与等效应变，并进一步阐明了在热力耦合分析中，机械负荷与温度负荷之间的关系；此外，还简介了Marc AutoForge程序结构的特点。

It provides a basic theory for the deformation property of combined torsion members. With the method, this paper, for the first time, discusses the nonlinear complete process analysis of high-stress concrete members subjected to combined force. It revises the strain-stress relationship contain of intenerate of concrete and simplifies the baroclinic theory of concrete. The calculation result fits the test result well, which proves that membrane-element theory is suit to reinforced concrete combined torsion members.

应用这种方法，本文首次对高强钢筋混凝土压弯剪扭复合受力构件进行了非线性全过程分析，对考虑软化的混凝土本构关系进行了修正，对混凝土斜压场进行了简化，经分析计算与试验结果对比符合较好，说明薄膜元理论对钢筋混凝土复合受扭构件受力行为的全过程分析是一种有效的方法。

In order to fully refect the geo-tech basic mechanics behaviors and to rationally explain the strain localization, this paper establishes the theory framework of gradient-dependent plastic model based on the theory framework of gradient-dependent plastic mechanics and in considering the plastic strain's gradient-dependence in double yield function, offers a kind of possible concrete pattern of the generalized plas...

为了较全面地反映岩土的基本力学性质，同时合理解释应变局部化现象，本文基于广义塑性力学的理论框架，在双重屈服函数中考虑了塑性应变的梯度依赖，建立了广义塑性梯度模型的理论框架，并给出了广义塑性梯度模型的一种可能的具体形式，分析了该模型的各个模型参数，尤其是其中的&局部化参数&的物理意义和可能对其产生影响的因素。

The foundation for further studying the strain gradient theory and applying the strain gradient theory to the fracture mechanics can be given by the result of this paper.

本文的结果，为进一步研究应变梯度理论在断裂力学中的应用提供了良好的基础。

In this paper, based on the couple stress theory, and MPUA theory, a finite elastic deformation theory considered micro-rotating was established according to the strain gradient theory.

本文是在偶应力理论和应距理论基础上，结合应变梯度理论而建立起来的一个考虑微旋转的非均匀有限弹性变性理论。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。