英语翻译 In the finite element method,the stiffness matrix is often obtained from the strain energy.According to the previous section,the non-zero stresses in the adhesive are the shear stresses τzx and τzy .Thus,the strain energy Va in the adhesive can be written as(公式省略). In this work,a quadrilateral element is adopted and the shape functions are as follows(公式省略). Within the quadrilateral element,the shear stresses can be expressed as(公式省略). where (τzx)i and (τzy)i are the shear stresses at the ith node.Using equation (12) for the shear stress in the adhesive,(τzx)i and (τzy)i can be written as(公式省略).