Hydromechanical Drawing Method And Process Optimization Of Aluminum Alloy Sheet With Reverse Drawing Structure

With the development of the modern manufacturing industry,there is higher requirements for sheet metal forming process.The research object of this paper is a kind of structural reinforcement plate for a type of aircraft,whose counter-drawing structure is a big problem in the forming of thin-walled sheet metal parts.In this paper,a new method of hydraulic deepdrawing composite forming with the addition of auxiliary punch is proposed.To verify the feasibility of the method,numerical simulation combined with experimental research is used.Finally,the Kriging model was built to shorten the preparation time of the new process in actual production and to obtain the best forming process parameters.The optimal process parameters were obtained by optimization algorithms.The main research contents are as follows.According to the geometric structure of the parts,the hydraulic deep-drawing composite forming method was proposed.Two forming method,including Hydromechanical reverse deepdrawing methods(HMRD)and reverse deep-drawing with hydro-bulging method(RDHB),were designed.To correctly simulate the forming process,the mechanical properties of 2A12 aluminum alloy were firstly determined by three-direction single tension test,and the finite element model of the forming process was established.The corresponding die was designed to test and verify the finite element simulation results.Using the thickness of the evaluation point as the evaluation value,the accuracy of numerical simulation was verified by comparing the simulation results with the experimental results.The finite element models of three different forming methods are established,and the forming effect and mechanism of the three forming methods are analyzed in the post-processing software.The result shows that HMRD method has a significant effect on improving the formability of materials.Then,the blank holder force and hydraulic loading curve of HMRD method were selected to carry out the control experiment,and the influence law of forming quality by adjusting the process parameters was determined.Finally,the accuracy of the results is verified by comparing of experimental results and simulation results.The initial data are constructed by finite element simulation,and Kriging model of HMRD was established.This Kriging model,combined with genetic algorithm was used to optimize the process parameters,the best process parameters were obtained.With optimal parameters,quality part was manufactured successfully in finite element simulation.