针对金属材料在屈服阶段塑性变形比较复杂且难以准确测量的问题,提出一种基于数字图像相关法的光学方法来测量H340LAD_Z高强度钢的塑性演变行为。首先,描述了DIC的基本原理,介绍了3D变形测量系统的使用;然后,拉伸与轧制方向平行的试件,并获取试件全场全过程变形数据;最后,通过分析并对比试件在屈服阶段的关键点位移及全场应变云图,揭示此试件的塑性变形演化规律及屈服阶段的开始与终了时刻。实验结果表明,此试件的演变行为从斜两侧向中间转移,塑性变形是不均匀的。因此,此方法对研究金属材料的塑性理论及工业应用都具有积极的指导意义。 Aiming at the problem that plastic deformation during the yielding phase is complicated and difficult to measure accurately, a plastic method based on digital image correlation method is proposed to measure the plastic behavior of H340LAD_Z high strength steel. First of all, the basic principle of DIC is described, the use of 3D deformation measuring system is introduced. Then, the specimen parallel to the rolling direction is drawn and the whole process deformation data of the specimen is obtained. Finally, by analyzing and comparing the specimen During the yielding stage, the key point displacements and the whole field strain cloud map reveal the evolution law of plastic deformation of this specimen and the beginning and end of the yielding phase. The experimental results show that the evolvement behavior of this specimen is shifted from the two sides to the middle and the plastic deformation is not uniform. Therefore, this method has a positive guiding significance for the study of plastic theory and industrial application of metal materials.