New finite element method to analyze crack tip of plate structure

In this paper a new finite element method to analyze the crack tip is proposed. Firstly the stiffness matrixes of the singular elements are completed on the base of the displacement field near the crack tip of the Reissner plate. Then the stiffness matrix of the singular element corresponding with the broad sense displacements is transformed into the stiffness matrix corresponding with the node displacements, so the latter can join the total stiffness directly. Finally the relativity between the displacements of the two singular elements is relieved, and the final stiffness is advanced. The new method, employing the transforming of the displacement and the conservation of the strain energy, focuses the calculation on the singular elements. So it not only decreases the quantity of the elements in the filed of the fracture, but also simulates the singularity of the crack tip, and the calculation near the crack tip is simplified not only in the theory but also in the calculation.