基于数字图像相关的力学测试系统设计与应用

针对电测方法需在试件表面粘贴应变片及单点测量局限,将数字图像相关方法(Digital Image Correlation,DIC)引入到材料力学性能测试分析中。设计二维DIC系统,并将其应用于三点弯曲沥青混凝土梁的变形和应变全场测试。根据应变云图,可以直观地观察到弯曲正应变沿梁横截面线性分布的特点。实验结果表明,DIC方法可以实现变形和应变分布的全场非接触和准确测量,可为土木工程试验提供可靠的测试手段。

Design and Application of Mechanical Testing System based on Digital Image Correlation

In order to overcome the limitations of both requirement of sticking strain gauge upon specimen surface and one single point measurement in electronic testing method, digital image correlation(DIC)method is introduced in the mechanical behavior analysis of materials. Two-dimensional DIC system is designed and applied for measurement of the asphalt concrete beam subjected to three-point bending loads. The whole-field deformation and strain distributions of the asphalt concrete beam are determined by the designed DIC system. According to the strain distributions, the linear distribution of normal strain along the cross-section of the bending beam is directly observed. The experimental results indicate that DIC can be used for non-contact and accurate measurement of full-field deformation and strain distributions, and can provide a reliable measurement technique for civil engineering experiment.