A novel method for measuring the weld property of tailor welded blanks based on DIC

A novel method,weld division method,was proposed to measure the mechanical properties of the weld zone in tailor welded blanks (TWBs). The weld zone was divided into the weld and heat affected zone according to the different minor strains in the direction perpendicular to the weld. The digital image correlation technology was employed to capture the strain filed in the TWBs surface when the weld failure occurred. A theoretical model was established to calculate the strength coefficient K and strain-hardening exponent n based on the previously achieved minor strain. To verify the proposed method,the curves of load vs. displacement were produced using finite element method by implementing the parameters from the division method, during uniaxial test of longitudinal weld in laser TWBs. Compared with the results from the rule of mixtures,those from the division method were closer to the experimental results, which indicates that the division method was more accurate.