Crashworthiness optimization of thin-walled tube structures with tailor-welded blank using targeting force–displacement method

Tailor-welded blank (TWB), one of the representative technologies in the modern manufacturing process, has the vast applied foreground in energy absorbers of automotive industries due to its significant advantages in better load-bearing capacity and lightweight. The mechanical performance of TWB structures is closely related to its thickness distribution and its location of weld lines. However, so far good algorithm has not been developed to design TWB structure considering concurrently these two aspects due to the time-consuming nature of impact dynamics and the complexity of TWB structure. To find its optimal thickness distribution and optimal location of weld lines, an optimization strategy is proposed to improve crashworthiness of the TWB structures. Firstly, the target force–displacement method is used to find thickness distribution of initial structures. Then, a finite element modeling technology of TWB developed to obtain the finite element model of TWB structures is automatically converted from that of the initial structures according to the results of the fore step. Finally, set uniform thicknesses constraint and find optimal thickness distribution of the TWB structure by using TFD method again. Compared with the existing methods, the proposed method comprehensively considers two important design objectives of TWB structures. Numerical results demonstrate the effectiveness of this method because it can obtain thickness distribution and location of weld lines of the TWB structure, and tailor the force–displacement response of the designed structure to closer a targeting force–displacement curve.