Optimization of initial billet for preforging forming of aviation large-sized complex titanium alloy bulkhead
Taking a TA15 titanium alloy bulkhead as an example,the combined method of numerical simulation,response surface analy-sis and physical simulation tests were used to optimize the shape and size of the initial billet formed by preforging forming.The parametric geometry model of the initial billet was constructed,and the finite element model of preforging forming and response surface test schemes were established.Aiming at simultaneous modeling of each area of the cavity,based on the simulation results of different initial billets,the quantitative correlation between geometric size of billet and die cavity filling was established,and the optimal geometric size of billet was calculated by solving the extreme value.Finally,the finite element simulation and physical simulation tests were used to verify the re-liability and accuracy of the initial billet optimization.The results show that the method can effectively overcome the common problems such as insufficient filling and excessive forming load in the preforging forming of large-sized complex titanium alloy bulkhead,and realize the simultaneous modeling of the preforging parts in different areas of the cavity.