Optimization of Process Parameters for Cracking Prevention of UHSS in Hot Stamping Based on Hammersley Sequence Sampling and Back Propagation Neural Network-Genetic Algorithm Mixed Methods

摘要

In order to prevent cracking appeared in the work⁃piece during the hot stamping operation, this paper proposes a hybrid optimization method based on Hammersley sequence sampling ( HSS) , finite analysis, back⁃propagation ( BP ) neural network and genetic algorithm ( GA ) . The mechanical properties of high strength boron steel are characterized on the basis of uniaxial tensile test at elevated temperatures. The samples of process parameters are chosen via the HSS that encourages the exploration throughout the design space and hence achieves better discovery of possible global optimum in the solution space. Meanwhile, numerical simulation is carried out to predict the forming quality for the optimized design. A BP neural network model is developed to obtain the mathematical relationship between optimization goal and design variables, and genetic algorithm is used to optimize the process parameters. Finally, the results of numerical simulation are compared with those of production experiment to demonstrate that the optimization strategy proposed in the paper is feasible.