非圓形斷面之薄壁壓力容器在空氣冷卻交換器、管道工程、材料壓縮箱體以及用於熱傳輸的特殊容器等領域具有廣泛的應用，而非圓形斷面之薄壁壓力容器目前的研究範圍大致著重於截面為矩形(rectangular)與長圓形(obround)的內壓結構(包含具強化與強化結構)。壓力容器在生產製造時，良好的結構設計可以提高材料成本效益，同時變形量與結構強度皆可符合限制需求，避免增加過多的重量與加工成本。廢料壓縮機的主壓縮箱為矩形薄壁壓力容器，薄壁容器於主油壓缸推進壓縮牧草時承載牧草形成之內壓，故引入加強肋構件讓矩形薄壁容器結構承載能力提升，避免結構產生過大的變形同時薄壁容器與加強肋之最大應力不超過降伏應力。本文利用有限元素軟體分析結構變形與應力分佈情形，其中主要的設計參數為：加強肋排列間距、形式、厚度以及高度等。本文利用有限元素軟體建立矩形薄壁壓力結構模型，然而有限元素模型建置與計算較耗時，故本文除了對矩形薄壁壓力容器在特定內壓條件下進行優化，同時推導出近似解析解方程式，提供在實際應用上較佳的分析效率又具足夠準確性之分析方法。本文中矩形薄壁壓力容器之設計準則為其最大變形量需小於特定限制條件且最大應力需小於材料(SS41鋼材)降伏應力，並利用ANSYS有限元素軟體建立分析模型，同時與近似解析解比較，從材料成本、強度、變形量等限制條件找出最適化設計方案，並由研究結果中提供矩形薄壁容器之設計依據。

The purpose of this study is to develop a simple and sufficiently accurate method to estimate deformation behavior of entire rectangular pressure vessel and investigate the influence of geometric parameters on ribs as well, which can be given as appropriate design suggestion in industry. For rectangular pressure vessels having reinforced members, the corner should be considered deformable. We take representative 2D model as analytical model and then derived the approximate analytical formulas. These formulas, including simplified and modified equations are suitable for different types of rib-reinforced vessels. The main difference between two equations is the shear rigidity. When the shear rigidity gets smaller, the results obtained by modified formula are more close to those by finite element method. In geometric parameters of rib, the height is more important than the width, so the height of rib should be major concerned in design. Moreover, rectangular vessels with radius corner make structure more compliant and significantly decrease the deflection than right corner one. It is evident that stress concentration phenomenon is located at the right angle corners, therefore it has to necessarily partly strengthen the corners. Another important thing observed in the results diagrams is that cross rib-reinforced type is the more effective and simpler reinforcing way to increase the ability of resisting deflection than ring rib-reinforced type.

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