自动网格法在轮胎橡胶力学行为测试中的应用

Application of Automated Grid Method in the Mechanical-Behavior Testing of Tire Rubber

本文利用自动网格法光学测量技术的非接触、高精度以及可以获得全场变形信息等优点,建立了一套包含图像采集功能的载荷-变形同步测试系统,来实施轮胎橡胶单向拉伸较大变形力学行为的测试.试验结果表明自动网格法适用于轮胎橡胶等软试件较大变形力学行为的测试,同时也验证了加卸载过程中,胎面碳黑填充橡胶(以下简称胎面胶)具有明显的迟滞效应、Mullins效应以及残余变形;而纵横向平均应变的数据则有力的证明了在单向拉伸的较大变形范围内,胎面胶是可压缩的,且体积比随轴向拉伸应变增大而逐渐增大.

A loaddeformation testing system is established for executing the uniaxialtension testing of the tire rubber in a larger deformation range. The automated grid method, as a effective photomechanical testing technique, is used in this system to measure the larger deformation of tire rubber. The automated grid method has some merits, including the nontouching form, the high accuracy and the ability to get the fullfield deformation information. The experimental results show that the automated grid method is very suitable for the mechanicalbehavior testing of the rubberlike soft materials. And it is also found that in the loadingunloading process, the carbonblackfilled rubber of the tire tread, i.e. the tread rubber, shows the obvious hysteresis, the Mullins effect and the residual deformation. Based on the transversal mean strain data and the corresponding uniaxial mean strain data, it can be concluded that the tread rubber is compressible in the larger deformation range of uniaxial tension, and that its volume ratio is gradually increased along with the increasing uniaxial tension strain.