Experimental and Simulation Study on Tube Bending and Hydroforming

Tubular bending and hydroforming expansion processes are studied experimentally and numerically in this paper. The experimental results show that the hydroforming process is sensitive to material grades and process variables, and the axial feeding used in this case causes more material deformation near the inner bending surface. Finite element analysis (FEA) was carried out on an S-shape bending and expansion process using the incremental code LS_DYNA. The simulation results successfully explain the phenomena occurring in the experiments. A methodology of analyzing tubular bending process using a One Step FEA code is proposed to improve simulation efficiency. This approach is validated by comparisons with both the incremental FEA predictions and the experimental results. One Step FEA is not only highly efficient but also reasonably accurate in predicting the deformation mode and thickness distributions during the bending operation.