本文使用ANSYS Workbench 14.0分析軟體，分析不同形狀之局部凹槽SUS304不鏽鋼圓管承受對稱曲度循環彎曲負載下之力學行為。圓錐體凹槽、半橢球凹槽與長方體凹槽共三種凹槽，凹槽尺寸以固定深度1mm而改變寬度0.5、0.75、1、1.25、1.5、1.75、2mm;與固定寬度1.5mm而改變深度0.4、0.55、0.7、0.85、1、1.15、1.3mm，且循環彎曲負載曲度控制在＋0.3〜－0.3m-1，分析的力學行為包括:彎矩(M)-曲度(κ)關係圖及橢圓化(ΔD/D)-曲度(κ)關係圖。由ANSYS分析結果顯示，不論是圓錐體凹槽、半橢球凹槽或長方體凹槽在彎矩(M)-曲度(κ)關係並無明顯差異，在橢圓化(ΔD/D)-曲度(κ)關係中，橢圓化呈現非線性棘齒狀(ratcheting)，而固定深度改變寬度或是固定寬度改變深度，隨著寬度或是深度的增加，棘齒狀(ratcheting)左右的不對稱的高低差越大，且在各個凹槽的橢圓化(ΔD/D)-曲度(κ)關係可看出，棘齒狀(ratcheting)左右高低差的變化程度，長方體凹槽＞半橢球凹槽＞圓錐體凹槽。

In this study, the finite element software ANSYS Workbench 14.0 is use to analyze the response of local-notched circular tubes with different notch shapes under cyclic bending. There are three types of local notches including circular cone, semi- ellipsoid and cuboid notches. The local notch widths include 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2mm with a fixed depth of 1 mm. And, the local notch depths include 0.4, 0.55, 0.7, 0.85, 1.0, 1.15 and 1.3 mm with a fixed width of 1.5mm. The range of curvature is controlled from +0.3 m-1 to -0.3 m-1. The analysis behaviors include moment-curvature and ovalization-curvature relationships. According to ANSYS analysis result, the notch depth and width have almost no influence on the moment-curvature relationship for any type of local notch. However, the unsymmetrical phenomenon of the ovalization-curvature relationship becomes more obvious. And, the ovalization increases when the notch depth or width increases. In addition, the increasing-rate of ovalization shows cuboid notch >semi-ellipsoid notch> circular cone notch.

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