The damage variable is defined as the residual strain of concrete under constant amplitude fatigue loading, and the law of cumulative damage and its evolution are obtained.
由等幅疲劳残余应变，定义了损伤变量，得到了相应的损伤积累和演化规律。
The test results show that the predicting fatigue life under variable amplitude loading follow the log normal distribution and agree well with simulation test results.
结果表明，变幅载荷下疲劳寿命的预测结果和模拟结果均服从对数正态分布，且两者符合很好。
The fatigue behavior of concrete under axial tension with constant and variable amplitude cyclic loading is investigated.
基于室内试验，研究了混凝土在等幅和变幅重复荷载作用下的轴拉疲劳性能。
Fatigue crack propagation behaviour under variable amplitude loading is significantly influenced by load history induced sequence effects.
导致加载序列作用的加载历史极大地影响着变幅加载下的疲劳裂纹扩展行为。
Therefore, it is necessary to evaluate the influence of overloads on crack growth rates for the fatigue life prediction of structures subject to variable amplitude loadings.
要准确预测结构在变幅载荷谱下的疲劳裂纹扩展寿命，必须研究超载对裂纹扩展的影响。
Many engineering structures are subjected to random loading in service. The load cycle interactions can have a very significant effect in fatigue crack growth under variable amplitude loading.
许多工程结构在服役过程中受到随机载荷的作用，载荷循环之间的相互作用对裂纹扩展将产生明显的影响。
The fatigue life with given survivability under variable amplitude loading is predicted, and checked by simulating test using Monte Carlo method.
预测了变幅载荷下给定存活率的疲劳寿命，并用蒙特卡洛法模拟变幅载荷下疲劳试验进行了验证。
This paper discussed the fatigue strength of single-spot-welded joints under constant and variable amplitude loading. The fracture mechanics was also used to analyse the experimental results.
讨论了恒幅及变幅载荷作用下，拉剪点焊接头的疲劳性能，并应用断裂力学对实验结果进行了分析和整理。
This paper bases on a part of the project of National Natural Science Foundation "Failure criterion of concrete under multiaxial variable-amplitude fatigue loading" (50078010) for study contents.
本文是基于国家自然科学基金项目《混凝土多轴变幅疲劳破坏准则》(50078010)中的一部分作为研究内容。
Variable-amplitude fatigue tests for concrete in tension under single and bi-lateral pressures are conducted. Consequently, the fatigue life and residual strain are obtained.
本文进行了混凝土分别在单、双向侧压作用下受拉变幅疲劳试验，得到了疲劳寿命和残余应变。
Found non-linear fatigue damage equation and fatigue failure criterion of concrete under variable amplitude load, and analyze the influence of loading sequence on total fatigue life;
建立了混凝土非线性疲劳损伤方程和变幅荷载下的疲劳破坏准则，分析了加载次序效应对总疲劳寿命的影响；
Found non-linear fatigue damage equation and fatigue failure criterion of concrete under variable amplitude load, and analyze the influence of loading sequence on total fatigue life;
建立了混凝土非线性疲劳损伤方程和变幅荷载下的疲劳破坏准则，分析了加载次序效应对总疲劳寿命的影响；
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