高擠製比靜水壓擠製之有限元素研究

Abstract

本論文之目的在於對高擠製比時之靜水壓擠製製程進行分析研究。論文中的研究集中在二個主題，高擠製比擠製和靜水壓擠製。利用ABAQUS中使用者副程式及後處理程式，建立ABAQUS自動網格重建之功能，使得高擠製比擠製時，網格因為變形劇烈產生數值無法收斂的問題能得到快速的解決。此外，在靜水壓擠製的有限元素模型中，使用流體元素來提供施加於工件上高壓流體的適當邊界條件。利用上述方式模擬出的預測值靜水壓擠製的實驗結果相當接近。

The purpose of this thesis is to investigate the numerical technologies used in analyzing the high extrusion-ratio hydrostatic extrusion. This study focuses on two subjects, high extrusion-ratio extrusion, and hydrostatic extrusion. By using user subroutines cooperating with postprocessing programs, a specialized automatic remeshing capability had been added to the ABAQUS/Standard. This auto-remeshing function was adopted to successfully solve the numerical divergence from serious mesh distortion occurred during high extrusion-ratio extrusion. In addition, fluid elements were adopted in the finite element model to apply the appropriate boundary conditions of high-pressure fluid surrounding the billet. The analytic results by using the above numerical technologies make good agreements with those from high extrusion-ratio hydrostatic extrusion experiments.