Mesh regularization in sheet metal forming of auto-body members for crashworthiness assessment

Abstract

A mesh regularization method is newly proposed in order to enhance the efficiency of finite element analyses in sheet metal forming. The mesh regularization method automatically finds out distorted elements with searching criteria proposed and composes patches to be modified. Each patch is, then, extended to three-dimensional surfaces in order to obtain the information of the continuous coordinates. The surface enclosing each patch is described as a three-dimensional free surface with the use of NURBS(Non-Uniform rational B Spline). On the basis of the constructed surface, each node is properly arranged to compose regular elements that have almost same length of sides and near right angles at the corner. Various numerical analyses have been carried out to confirm the efficiency of the mesh regularization method proposed and the accuracy of the result. It is also noted that the present method is effective in the structural or crash analyses of sheet metal members obtained from the forming simulation. The present approach directly applies the simulation result to the crash analysis while the crash analysis model is usually reconstructed from the result of the forming simulation by mapping the state variables in other analysis procedures.