Determination of Low-carbon Steel Specimen Elastic-Plastic Boundary Using Improved White-light Correlation Method
低碳钢试件弹塑性边界的白光相关检测

Determination of elastic-plastic boundary and plastic strains on the surface of metal specimen has long been an attracting and challenging research topic and also is meaningful in determining whether the specimen is in the failure state or not.Both laser speckle and white-light methods have been presented to measure the elastic-plastic boundary and plastic strains of the specimen.To avoid the shortcomings accompanying the laser method,an improved and simple optical method is proposed to determine the elastic-plastic boundary of low-carbon steel specimen in this paper,which using white-light scattering generated by plastically induced surface roughness on the metal specimen polished surface.By digital processing of consecutive images acquired during load, it is possible for us to accurately determine the initiation of the plastic strain.