聚碳酸酯在高应变率下的动态力学性能研究

Study on Dynamic Mechanical Properties of Polycarbonate at High Strain Rates

采用实验和理论分析方法对材料在高应变率下的动态力学性能进行了研究。不同应变率条件下聚碳酸酯材料的动态变形行为由高速相机采集系统和二维数字散斑相关方法获取。采用一级轻气炮装置开展了平板撞击试验,测定了材料一维平面波下的Hugoniot关系。实验结果表明:通过改进的分离式霍普金森杆所测得的应变与二维数字散斑相关技术(2D-DIC)得到的结果吻合。聚碳酸酯的抗压强度、抗拉强度和弹性模量均随着应变率的增加而增加。随后,基于最小二乘法完成了冲击波速度和质点速度关系的Hugoniot状态方程:D=2.39+1.55u。

The acquisition system of high-speed camera and 2D digital speckle correlation (DIC) method were used to obtain the dynamic deformation behavior of polycarbonate under different strain rates. Plate impact experiments were conducted in a single-stage gas gun to measure the Hugoniot relations under one-dimensional planer shock waves. Experimental results showed that the strain acquired by improved split Hopkins bar had a good agreement with 2D-DIC techniques. Compressive strength, tensile strength, and elasticity modulus of polycarbonate were increased with increasing of strain rates. The Hugoniot relation between shock wave velocity and particle velocity was fitted by the least square method under shock wave loadings, which was D =2.39+1.55 u .