循环载荷下AH32钢低周疲劳与累积塑性破坏交互作用试验研究

文章对AH32钢在循环载荷下低周疲劳破坏和累积塑性破坏的交互作用进行了试验研究.试验中分析了平均应力、应力幅值及应力比对低周疲劳裂纹扩展寿命和累积塑性应变的影响.试验结果表明,较大的循环载荷下发生两种失效模式,由裂纹扩展导致的低周疲劳失效和较大的塑性应变导致的累积塑性破坏.在试验结果的基础上,文中提出了考虑低周疲劳破坏和累积塑性破坏交互作用的失效模型,模型结果与试验结果较为吻合,说明其具有一定的可行性.

Experimental Study on Interaction of Low Cycle Fatigue and Accumulative Plastic Damage of AH32 Steel in Uniaxial Cyclic Loading

In this paper, the low cycle fatigue failure and accumulative plastic damage, as well as their interaction of AH32 steel were experimentally investigated in uniaxial cyclic loading. The effect of mean stress, stress amplitude and stress ratio on the low cycle fatigue crack propagation life and accumulative plastic strain are discussed. It is found from the experimental results that two kinds of failure modes, i.e. low cycle fatigue failure due to crack propagation and accumulative plastic dam-age due to large plastic strain will take place simultaneously. Based on the experimental results, the low cycle fatigue failure model is proposed to predict the fatigue life of the material accounting for the coupling effect of low cycle fatigue-accumulative plastic strain interaction. Comparison with the experimental result shows that the model provides a good prediction for AH32 steel.