Strain optical detection technology applied for bi-metal clad plate using digital speckle correlation method

Bimetallic clad plates have excellent comprehensive performances and are widely used in aviation, aerospace, automotive and other fields. During the process of manufacturing, the great changes of formability have taken place.Most of the traditional single metal research methods can not meet the needs of the development of new materials, which seriously hinders the industrialization of bi-metal cladding materials.Aiming at this problem, a digital speckle correlation method was proposed to apply in the bi-metal cladding material structure and field engineering deformation measurement. The domestic and foreign research situations at present and existing science problems were analyzed, the strict theory of digital speckle correlation method used in strain optics testing and the mechanism of forming performance for cladding materials were revealed, and the related research content were studied. The proposed four strain values were verified by mutual comparison, which can improve the strain accuracy by 5%, and achieve the purpose of reproducing material strain history and dynamic tracking, improving the full field strain accuracy detection, optimizing the material configuration ratio and perfecting the forming performance.