本研究是以有限元素分析軟體ANSYS分析316L無縫不鏽鋼薄壁圓管，承受對稱曲度循環彎曲負載下的力學行為，該行為包含有彎矩、曲度及橢圓化的相互關係。在有限元素ANSYS分析中，本文使用兩種不同元素種類以及兩種不同網格大小來分析圓管，再將有限元素ANSYS分析結果和已發表的Endo理論(內涵時間理論結合虛功原理)的運算結果及實驗結果進行比較。
本文所使用兩種不同元素種類分別為，彈塑性元素SHELL93及塑性元素SHELL143，分析結果發現兩種類分析的彎矩-曲度關係相當近似，但橢圓化-曲度關係則以彈塑性元素SHELL93和實驗結果較為接近。至於在兩種元素切割網格數大小分別為8×31及12×36，分析結果發現使用較少的網格數目可得到相同結果。此外，ANSYS分析結果與Endo理論運算結果比較後發現，雖然ANSYS的理論分析並無法顯示出彎矩-曲度關係的循環硬化現象，但穩定迴圈的彎矩-曲度關係卻是相當的接近，而且兩者所分析的橢圓化-曲度關係也非常相似。由於ANSYS有限元素分析可以省略繁複的計算過程與消耗的時間，本文認為有限元素ANSYS分析可以取代Endo理論運算圓管彎曲負載的力學行為。

The purpose of this thesis is to use finite element software ANSYS to analyze the mechanical behavior of thin-walled 316L stainless-steel tubes subjected to curvature-symmetric cyclic bending. The mechanical behavior contains the relationship among bending moment, curvature and ovalization. There are two kinds of element and mesh, which are used in ANSYS analysis. In addition, the analysis result obtained by ANSYS is compared with the Endo theory (combines the endochronic theory and principle of virtual work) and the experiment result.
There are two kinds of element are considered in this study, which are SHELL 93 and SHELL 143. Based on the analysis result, the relationship between the bending moment and curvature is similar, but element SHELL93 has closer result of the relationship between ovalization and curvature with the experiment data. As for the mesh, there are two kinds of mesh in this study, which are 8×31 and 12×36. It is found that the analysis result of using 8×31 mesh almost equals to that of using 12×36 mesh. In addition, by comparing the analysis result by using ANSYS with the analysis by using Endo theory, it is found that although the cyclic hardening of the moment-curvature curve does not show by using ANSYS, the steady-state loops of the moment-curvature curve are very close for those two methods. Furthermore, the simulations of the ovalization-curvature curve are very similar for the two methods. Due to reduce the complicated process of counting by using ANSYS, this thesis suggests that the ANSYS analysis can replace the analysis by the Endo theory.

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