Comparative study of finite element analysis in tube hydroforming of stainless steel 304

摘要

This research conducts a comparative study of finite element analysis (FEA) in tube hydroforming (THF). The investigated tube is stainless steel grade 304 (SS304) of as received and after annealing (AN). Three different finite element modeling techniques have been examined and compared with corresponding experimental results. The main modeling parameters of interest range from element technologies, symmetry modeling, and solving schemes. Other parameters being sensitive to each model are discussed. Formability issues have been investigated through FEA and forming limit diagram (FLD). Computational aspects have been illustrated and discussed for simulating THF and an intermediate AN. Prediction of the required forming pressure is challenging. Both shell and continuum elements have different advantages and drawbacks in simulating THF. A shell element with explicit time integration tends to underpredict the required forming pressure while both axisymmetric and 3D continuum elements with implicit time integration tend to overpredict the required forming pressure. The draw-in observation can also provide an insight of the state of deformation.