The Study Of Body Lightweight Method Based On The Tailor-welded Blank Structure

The tailor-welded blank(TWB) has the advantages of weight reduction, improve the structure performance, improve assembly accuracy and reduces the production cost, has been gradually applied in automotive lightweight design. However, the traditional designs of tailor-welded blank mainly depend on the expert experience, TWB lack of uniform design methods. The method waste of manpower, material and financial resources, but also it is difficult to ensure the performance of TWB parts. Therefore, lightweight design study for the TWB parts has great significance and value.This paper using TWB structure to study the lightweight design of the automotive door, through the weld model of simulation, the weld position influence on formability of TWB parts, weld arrangement and blank block, combined with DOE and optimization algorithms to achieve the purpose of lightweight design. The main research content is as follows:1. Comparison of the current total node weld connection, rigidly connection, beam element and shell element connection instead of weld, because of different weld connection may influence the results of the simulation. Considering the accuracy of the results and the simulation time, the results show that the total node weld connection has high accuracy and reliable.2. Using total node weld connection instead of weld model, analyzed the influence of the weld position on TWB formability. Analysis the weld arrangement affect on forming of convex, concave to the stamping parts, the TWB performance be improved by reasonable arrangement weld received from forming simulation analysis.3. Taking the front door, which is a closed component of the body in white, as an instance, the study of body lightweight design based on the topology optimization method and modern optimization method. The topology optimization about door structure with the SIMP(solid isotropic material with penalization) is researched, obtain the spatial distribution of the material and get inner door panel of weld arrangement by the distribution of the material.4. Considered free modal and stiffness to carry out a sensitivity analysis on the original door, calculate sensitivity value of the parts of every performance, and select the design variables based on the step 3. The approximate mathematical model for each response is builded by Latin Hypercube experimental design and Kriging method, and on this basis, the approximate model carry out optimization with the sequential quadratic programming. The results show that under the premise of that the free modal, stiffness and crashworthiness is essentially the same or even improve, the weight of the door system is reduced greatly by TWB structure, which make an effective method for the application of TWB structure in auto body structure design and lightweight design.