本研究應用有限元素法與邊界積分式相互耦合的原理來探討三維彈性力學的問題。當處理無限區域問題時，在實體邊界的外部設定一封閉的假想邊界，以二十節點等參元素分割兩邊界所圍成的有限元素區域，其邊界上則採用八節點等參元素。假想邊界上的拘束條件由邊界積分式求得，因為源點與場點不重合，所以不會產生奇異性積分問題。探討有限區域問題時，則將假想邊界設在實體邊界的內部，因為不需對整個定義域分割，所以可使用較少的元素。所得的數值解與解析解相比極為準確，證實本文方法應用在彈性力學的領域上，為一有效且可靠的數值方法。 This study presents the application of the coupled Finite Element Methed (FEM) and Boundary Integral Equation (BIE) to determine the problems in 3D elastostatics. For infinite domain problems, it is supposed that there exits a closed artificial boundary exterior to the real boundary. The finite region is discretized by finite element mesh with twenty-noded isoparametric element, and the boundary using eight-noded isoparametric element. The constraints on the artificial boundary are formulated by BIE. Because the source points and field points are not in the same positions there will be no singularity problem. For finite domain problems, it is supposed that there exits a closed artificial boundary interior to the real boundary. It is not necessary to discretized the whole domain and using less elements. The numerical results are very accurate compared to analytical solutions. It is proved that this method is an efficient and reliable numerical method in handling the elasticity problems.
