AZ91D室温环境棘轮及其低周疲劳行为

Ratcheting and Low Cycle Fatigue Behavior of AZ91D at Room Temperature

通过AZ91D室温环境应力控制下的低周疲劳试验,对铸造镁合金棘轮及其低周疲劳行为进行了研究,讨论了室温环境下材料的应力循环特性、棘轮行为、塑性应变范围、全应变范围等疲劳参量随载荷水平和加载历史的变化规律,同时基于平均应力修正对材料的应力-寿命曲线进行了讨论。研究结果表明:AZ91D在室温环境下的应力循环呈循环硬化,材料的棘轮行为和塑性应变范围、全应变范围等疲劳参量依赖于载荷水平和加载历史,另外考虑平均应力修正后的应力-寿命曲线预测效果有明显改观。

By low cycle fatigue experiments at room temperature under stress control, the ratcheting and low cycle fatigue behavior of cast magnesium alloy AZ91D were studied. In this research, the effects of load level and loading histories on the stress cycle characteristic, ratcheting behavior, plastic strain range and total strain range of AZglD were discussed. And then, the stress-life curve was analyzed based on the mean stress modification. Results show that the stress cycle of AZglD at room temperature exhibits cyclic hardening. The ratcheting behavior, plastic strain range and total strain range of AZ91D depend on load levels and loading histories. In addition, compared with the stress-life curve without modification, the prediction effect of the stress-life curve with the mean stress modification is significantly improved.