利用数字图像关联技术评价固体材料的应变

Using digital image correlation technology to evaluate strain of solid materials

为了研究基于数字图像关联技术(DIC)在材料应变测试中的精确度及使用范围,采用接触式引伸计、电阻应变片和DIC三种测试技术,分别对不锈钢、SiC/SiC复合材料和石墨弹性模量及在拉伸过程中的应变进行测试与评价。结果表明,三种测试技术测得的每种材料的弹性模量基本一致;但DIC在固体材料应变评价中的精度足以和引伸计相比,并弥补了电阻应变片的测量范围有限和引伸计不能全程测量的不足。

To investigate the accuracy and the application range of DIC, three techniques, contact extensometer, resistance strain gauge and DIC, are used to measure the elastic modulus and the strain of stainless steel, SiC/SiC ceramic matrix composites and graphite respectively. The results show that the elastic modulus measured by the above three methods is basically the same. However, DIC not only possess the accuracy of extensometer, but also remedy the deficiency of the limited measuring range of the resistance strain gauge and the incomplete test procedure of the extensometer.