本文旨在研究異向性反平面裂紋體塑性區大小之評估，以異向性Stroh公式為基礎首先推演格林函數，並以連續差排的觀念模擬裂縫行為，建立以差排密度函數為未知數的奇異積分方程式，再以Gerasoulis數值方法求解未知差排密度函數，進而推導出應力強度因子，塑性區大小乃基於Dugdale’s Model理論進行評估，針對不同邊界，異向性程度對裂紋塑性區大小之影響提供了數值結果。

The aim of this study is to estimate the plastic zone size of anisotropic anti-plane cracked problem. The Green function is introduced based on the Stroh formalism which deals with anisotropic elastic materials. By simulating the behavior of cracks by a continuous dislocation density, the singular integral equation for the problem with dislocation density as the unknown function is developed. The unknown dislocation function is determined by Gerasoulis’ numerical method and the corresponding stress intensity factor are directly obtained. The plastic zone size is estimated by Dugdale’s Model. Numerical results of the plastic zone size are presented to see the effects of the different boundary conditions as well as the degree of anisotropic of the materials.

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