在本文之中成功的發展出新的裂紋尖端邊 界元素稱為---振盪奇異元素(Oscillatorily Singular Boundary Elements)用以分析兩種材料間的界面裂紋 。這種元素之內部應力及位移場分別是 r/sup (-1/2+1.epsilon.)/及r/sup (1/2+1.epsilon.)/的形式, 因此可用來模擬界面裂紋尖端附近的應力及位 移場。利用這種振盪元素並配合邊界元素法作 為數值分析的工具,可以得到準確的複數型應 力強度因子K/sub 1/+iK/sub 2/,以作為判定裂紋是 否延伸的設計參數。在與目前用來分析界面裂 紋的邊界元素技巧比較之後,發現本文中所提 出的方法能夠更快速且準確的求得結果。 New crack tip boundary elements are developed in this thesis. Stress and displacements are of the form r/sup (-1/ 2+1.epsilon.)/ and r/sup(1/2+1.epsilon.)/ respectively. Therefore they may be used to simulate stresses and displacements close to a bimaterial interface crack tip. These elements, called the oscillatory singular elements, are used together with the boundary element technique. The complex stress intensity factor K/sub 1/+iK/sub 2/ may be accurately obtained. By comparing the proposed technique to the pre-existing boundary element technique, we find the proposed technique is much more efficient and accurate. The interface crack in an infinite body is analyzed first. The best mesh arrangement is found by comparing the stress intensity factors to the known analytical solutions. Then interface cracks in finite bodies are analyzed. The relationship between SIF and crack length are determined.
關聯:
中華民國力學學會第十六屆全國力學會議論文集(二)=Proceedings of the 16th National Conference on Theoretical and Applied Mechanics (II)，頁495-502
