結構設計中有時因為人為或其他因素，使得構件表面出現缺陷；若一有限寬板的表面具有缺陷時，產生的幾何不連續將導致應力集中現象發生。針對應力集中的現象，本研究利用有限元素軟體進行寬板含有半圓或半橢圓槽口受張力作用的模擬分析，因半圓的形狀可透過解析解進行計算，故可提供有限元素軟體分析結果之比對使用。本研究並探討槽口為單一、上下對稱與上下錯位三種案例，透過變數為板寬、槽口間距離進行應力集中係數影響之探究。經驗證後的模型可確認有限元素軟體的可行性，進而討論半橢圓槽口長軸變化對應力集中的影響。分析結果顯示隨著板寬、上下槽口間的距離增加，應力集中係數會逐漸趨於定值；而半橢圓槽口之長軸逐漸增大，應力集中係數則會由小變大。依照有限元素軟體能有效得出結果的特性，未來可更深入進行不規則形狀槽口、不同材料或槽口數量對應力集中產生影響之研究。

Sometimes in structure design because of human or other factors, the surface of the component defects; If the surface of a finite width plate is defective, the resulting geometric discontinuity will result in stress concentration. In order to solve the stress concentration phenomenon, the finite element software is used to simulate the tension of wide plates with semi-circular or semi-elliptical notches. Since the shape of semi-circular can be calculated by analytical solutions, the comparison of the finite element software analysis results can be provided. In this study, three cases of notch being single, symmetrical up and down, and dislocation up and down were discussed. The influence of stress concentration factor was explored through the variables of plate width and notch distance. The verified model can confirm the feasibility of the finite element software, and then discuss the influence of the change of the major axis of the semi-elliptical notch on the stress concentration. The results show that the stress concentration factor tends to a constant value with the increase of plate width and the distance between upper and lower notch. The stress concentration factor increases from small to large when the major axis of the semi-elliptical notch increases gradually. The effect of irregular notches, different materials, or the number of notches on stress concentration can be further studied in the future based on the effective results obtained by finite element software.

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