Sub-region mixed finite element analysis of V-notched plates

Abstract

In this paper the eigenproblem of elastic plates with V-notches is studied in terms of the complex potentials of elasticity. The variation of the eigenvalues as functions of notch angle is discussed. The phenomenon of bifurcation in the curves of higher-order eigenvalues is discovered and the concept of ‘critical angle’ is proposed. Furthermore, a singular stress element, according to the stress field around notch-tips, is developed to account for notch-tip singularity. Moreover, conventional regular displacement elements are used outside the singular stress element, and then the basic finite element equations can be established based on the sub-region mixed energy principle. In two numerical examples, the stress intensity factors K _I and K _II of the notched specimens with various opening angles are evaluated, satisfactory accuracy can be obtained with very coarse meshes.