数字图像相关法在材料拉伸试验中的应用

Application of digital image correlation method in a material tensile test

数字图像相关法是基于计算机视觉技术的一种非接触全场应变测量技术,为了研究该方法在材料拉伸试验中的应用,设计完成了板型试样的拉伸试验,分别采用数字图像相关法和传统引伸计方法对钛合金拉伸试样的应变进行测量,同时考查了加载速率对材料弹性模量测量结果的影响。结果表明,不同加载速率对材料弹性模量的测量结果影响较小,本文的测量结果与材料手册中数据的误差在3%以内,数字图像相关法与引伸计的测量结果具有可比性,测量结果十分接近,且数字图像相关法具有全场、非接触、显示直观的优点,表明该方法在工程中具有较好的应用前景。

The digital image correlation method （DICM） is a non-contact strain measurement technology based on the computer version technology. In order to evaluate its accuracy in the tensile test, a specimen with plate shape was designed and tested. The strain was measured by using the DICM and extensometer. In addition, the effect of loading speed on the modulus of elasticity was analyzed. The results indicate that the loading speed has little effect on the test results, and the errors of the modulus of elasticity between this work and that in the handbook are below 3%. The strain results obtained by the extensometer and DICM are comparable and close. The DICM has advantages of full-field and non-contact, which demonstrate that this method has great prospect in application.