本文應用貼紙格線／數位相機／影像處理軟體，量測試片中央類橢圓孔前端之應力分佈；來驗證以能量守恆法則，從彈性應力轉換而成之彈塑性應力之精確性。本文先應用能量守恆法則，推導出彈性-彈塑性應力之轉換公式。再進一步將試片中央類橢圓孔前端應力集中放大部位內，由彈性應力分佈公式計算得之彈性應力，轉換成彈塑性應力。吾人發現：與先前論文針對具有中央圓孔之試片所得結果類似，轉換計算之彈塑性應力，較量測應力略小。
We verified the conversion of the elastic to the elastic-plastic stress profile in front of a quasi-elliptical notch on the basis of strain-energy conservation, with the strain measurement using a network grid, digital camera and image-handling software. First, we derived a formula to convert an elastic stress to an elastic-plastic stress based on the conservation of strain-energy. Then, we calculated the elastic-plastic stresses in front of the quasi-elliptical notch from the elastic-stress distribution derived from a published formula. Comparing with the measured stress distribution using the grid-tab/digital camera/image-handling software technique, such calculated elastic-plastic stress profile is a little bit lower than the measured stress profile. The results agree well with the previous conclusions we obtained for the central-circular notch.
