| Summary: | 碩士 === 元智大學 === 機械工程研究所 === 81 === A computational method for the simulation of axisymmettric
sheet metal forming processes such as stretching, deep drawing
and hydroforming is presented. The elastic-plastic finite
element method with large strain formaulation is applied to
simplify the procedure of the analysis. The total Lagrangian
formulation and virtual work theory are used to derive the Von-
Mises flow rule which satisfy Hill's rate-independent normal
anisotropic relation is adopted. In the contact region, the
relative motion between sheet and punch is governed by Coulomb
friction law. Newton Raphson method is then used to solve the
nonlinear problem. Some examples on stretching, drawing and
hydroforming of sheet metal are considered, and the computed
results are compared with experimental data and existing
numerical solutions. Both the strains and the punch load
obtained with above method agree well with the experimental
results. From the comparison of strain distribution between
deep drawing and hydroforming, it is favour to use
hydroforming process to promote the formability of sheet metal.
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