工業上的金屬冷擠成形加工法，具有諸多優點。但由於擠製過程，材 料含有複雜的塑性流動問題，故曾有多位學者利用上界限法，來深討金屬 擠製成形的問題。
本文研究之主旨，在依據上界限定理，提供一種簡易的元素劃分法， 將複雜的塑性流動問題予以簡化。依元素的邊界條件，分別建立各元素的 近似運動學的容許速度場。然後利用最佳化理論的可撓性多面體尋求法， 以決定最佳的容許速度場，進而導出應變率場，來估算各型元素因内部變 形、剪應力及摩擦所損耗之總功率，而求得冷擠成形所需的沖頭壓力。
本文並設計製造六種不同尺寸的模具，再以鋁為材料，施以冷擠實驗 。而將所得的實驗值與電腦計算的理論值相比較，結果兩者極為接近。
可見不需全靠高深的數學理論來描述材料複雜的塑性流動問題，由本 文提供的元素劃分法及電腦程式，可供給工業界人士，據以求得各種成品 擠製成形所需的沖頭壓力。

On account of continuous demand of petroleum fuel internationally, the huge amount of tanker replacement and new-building construction will be the principal market in shipbuilding industries. With regards of environmental pollution caused by oil leakage over shipping accidents, the new official regulations emphasised on double hull tanker construction are detailedly announced by U.S.C.G. (United States Coast Guard) and U.N. (United Union) IMO/MEPC.
In compliance with new requirements of tanker construction, an economical VLCC(Very Large Crude Oil Carrier) design is effectively developed for international business promotion in shipping industries. This design is based on the existed hull lines of C.S.B.C.(China Shipbuilding Corporation) 260,000 DWT VLCC and achieved by satisfying new regulations for tanker construction and by increasing ship depth and draught to meet basic requirements of 335,000 cubic metre cargo oil capacity and
280,000 DWT (Deadweight) respectively.
In this paper, the major content of design work extensively covers the hull form determination, cargo hold arrangement, resistance and propulsion performance, damage stability and longitudinal strength calculations. The final achievement of this new VLCC design is of superior quality and could be a good deal in the near fixture. Indeed it could be a useful experience of ship design work of different kinds for practical engineering applications.