A criterion for fatigue under multiaxial states of stress
A criterion for fatigue under multiaxial states of stress
复制标题
多轴应力状态下的疲劳准则
DOI：
10.1016/0093-6413(74)90068-8
复制
发表时间：
1974
影响因子：
2.4
通讯作者：
F. Ellyin
中科院分区：
文献类型：
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作者：
F. Ellyin
长期以来，工程师们的目标是能够从容易获得的性能来预测金属的疲劳寿命。这些特性中的一些是循环应力-应变曲线和疲劳延性特性。根据Morrow [i]的说法，到1965年为止，至少有一百种金属疲劳理论，而且从那时起，这一数量可能还在明显增加。试图从微观尺度获得洞察力，以发展一种唯象疲劳准则，可以得出以下结论：循环塑性应变与位错运动有关，循环应力与位错运动阻力有关。因此，位错所需的应力和塑性应变导致机械能的耗散（磁滞回线）。因此，每个循环的塑性应变能可以被认为是每个循环的疲劳损伤量的复合度量，并且金属的抗疲劳性可以根据其吸收和耗散塑性应变能的能力来表征。Morrow [i]回顾了1965年之前建立基于能量的疲劳标准的尝试。其基本思想是，由于可塑性，在每个周期中都会有少量能量变得不可恢复。当重复循环的结果是累积的总能量等于静态测试确定的断裂所需的能量时，材料将因“疲劳”而失效。
It has long been the goal of engineers to be able to predict the fatigue life of metals from easily obtainable properties. Some of these properties are the cyclic stress-strain curve, and the fatigue ductility properties. It is in keeping with this desire that according to Morrow [i], there were at least one hundred theories of metal fatigue up to 1965, and the number may have been increased appreciably since then.Attempting to gain an insight from the microscopic scale to develop a phenomenological fatigue criterion, one may conclude the following: The cyclic plastic strain is related to the movement of dislocations, and the cyclic stress is related to the resistance to their motion. Thus stresses and plastic strains required for dislocation result in the dissipation of mechanical energy (hysteresis loop). Therefore, the plastic strain energy per cycle may be regarded as a composite measure of the amount of fatigue damage per cycle, and the fatigue resistance of a metal may be characterized in terms of its capacity to absorb and dissipate plastic strain energy. Morrow [i] has reviewed attempts prior to 1965 to establish a criterion for fatigue based on energy. The basic idea is that a small amount of energy is rendered irrecoverable at every cycle owing to the plasticity. When, as a result of repeated cycling, the total energy accumulated becomes equal to the energy required for fracture as determined by a static test, then the material will fail by" fatigue".