Sheet metal parts are important parts of aircraft body and automobile body

in order to shorten the production cycle of sheet metal parts

finite element method is used to evaluate the manufacturability of parts in the initial stage of part design. In order to improve the calculation efficiency of the existing finite element method of sheet metal forming and ensure the simulation accuracy

based on the theory of one-step quick forming finite element method

multistep quick forming finite element method was studied. The influence of loading path and deformation history in sheet metal forming process is considered by introducing intermediate configuration. The structure of intermediate configuration is the key of multi-step quick forming finite element method

the intermediate configuration is decoupled into two independent processes of bending deformation and tensile deformation

which were calculated. In the bending deformation stage

the slip constraint surface is calculated according to the position relationship between the sheet and the die without considering the material flow. At the stage of tensile deformation

the material flow is restricted to the slip constraint plane

and the intermediate configuration is obtained through stress balance iteration and node modification. Taking a typical sheet metal part as an example to simulate the forming

and comparing with the existing commercial finite element software in calculation accuracy and efficiency

the feasibility and effectiveness of the algorithm are verified. The results show that the proposed algorithm can quickly construct reasonable intermediate configuration and accurately predict the formability and thickness distribution of parts.