Integrative measurement method for tensile test based on DIC using modified second-order shape function

Abstract

Conventional tensile tests still require significant manual intervention for assessment. Therefore, the digital image correlation (DIC) technique is introduced into the field of conventional tensile test. Flexible chain, chain subset-based DIC (C-DIC) technique and modified second-order shape function (MSSF) are proposed for methodology and implementation. Tensile tests of several standard metal specimens were carried out to validate estimation accuracy and effectiveness of the proposed method. Various material properties (e.g. necking effect, elastic modulus, ultimate elongation and necking stress–strain curve) have been automatically measured by the proposed method. The relative errors of different material properties measured by the proposed method are generally less than 3% compared to that of conventional methods. The efficiency and accuracy of the proposed method, validated by experiments, demonstrate its capability to achieve automatic measurements for tensile tests. These results suggest that the method has the potential for widespread industrial adoption in the field of tensile testing.