聚碳酸酯非比例多轴棘轮行为的实验研究

Experimental Study on Non-Proportional Multiaxial Ratcheting Behavior of Polycarbonate at Room Temperature

在室温下,对聚碳酸酯进行了一系列非比例加载路径下的循环变形实验。首先讨论了不同非比例路径对聚碳酸酯多轴棘轮行为的影响,其次讨论了轴向平均应力和应力幅值及其历史的影响。实验结果表明:聚碳酸酯在不同非比例路径下均产生了明显的棘轮行为,且棘轮变形的大小明显依赖于加载路径的形状;非比例多轴棘轮行为明显地依赖于轴向平均应力和应力幅值的大小及其历史。

Experimental observations were performed to investigate the non-proportional multiaxial ratcheting behavior of polycarbonate polymer under stress-controlled cyclic loadings at room temperature. The dependence of multiaxial ratcheting behavior on different nonproportional loading paths, such as the square, hourglass-type, butterfly-type and octagonal paths, was investigated firstly; and then the effects of stress levels on the multiaxial ratcheting behavior were discussed. The results show that the multiaxial ratcheting behavior occurs mainly in the axial direction since only the non-zero axial mean stress is used and the mean shear stress is set to be zero in all the prescribed multiaxial loading paths. The axial ratcheting strain depends significantly on the shape of loading paths and increases with the axial mean stress and stress amplitude, and it also depends on the loading history.