Research On The Unfolding Algorithm Of Complex Sheet Metal Parts And Its Parallelization

With the development of sheet metal stamping industry,parts geometry began to diversify,stamping process is also increasingly complex.The traditional one-step inverse method predicts the initial solution of the part,and the setting of blank holder force is too dependent on the experience value.With the increase of parts complexity,the problem of over-constraint and lack of constraint in the grid projection process begins to be highlighted.Therefore,this paper presents a parallel algorithm for blanks unfolding of complex sheet metal parts.The adaptive equivalent boundary force algorithm for complex sheet metal parts deployment is proposed.By extracting the internal force of the unit to solve the equivalent boundary force,the function relationship between the node spacing and the unit internal force is constructed,the resistance setting of blank holder and drawbead in the actual stamping process is effectively simulated,The equivalent boundary force calculation formula based on the internal force of component unit is deduced.Proposed an initial solution algorithm based on grid parameterization,by dividing the complex profiles into sections,the section layer with the largest number of unit nodes is determined.Solve the normal angle of the unit,and complete the parameterized projection of the grid based on the adaptive solution of the constrained point connected area.The algorithm solves the problem of overconstraints and lack of constraints caused by the complicated geometric features of the part,the solution to the shape of the blank for complex sheet metal parts is realized.A parallel algorithm for complex sheet metal parts unfolding based on OpenMP is proposed.The main work is to parallelize the process of unit node cycle,data accumulation,extremum mean value calculation and matrix multiplication in the initial solution of complex parts.In the realization of the blank holder force solution and grid parameterized predictions at the same time ensure the efficiency of the program.Finally,the car hood inner panel is validated to verify the accuracy of the algorithm when solving the complex shape of sheet metal blank,and compared the efficiency of parallel algorithms based on OpenMP for complex sheet metal parts.