Improvement And Implementation Of The Extended Finite Element Method On Abaqus And Application On Bioceramics

Extended finite element method (XFEM) is a new method to solve the discontinuous problems, and it inherits all the advantages of conventional finite element method, meanwhile the mesh need not in accordance with the edge of internal geometry or physical interface.However when XFEM is used to solve the problem, only the nodes of the crack tip element were enriched by the crack tip field function, it will be vanish when the size of the element is very small, And it decreased the accuracy. SO is very important to Determinate the nodes to be enriched around the crack tip by the crack tip field function.In this paper, XFEM was implemented in the commercial finite element code ABAQUS as a user element (UEL) subroutine. Two different integration schemes were selected to test and verify the UEL code. Compared the two schemes, it concluded that fewer integrate points can obtain the same degree of accuracy as more integrate points scheme does.First, choose two different integration schemes proved that the procedure is correct, and can get high accuracy using few integrate points. Then a formula was given to decide the radius of the crack tip field. In the end this method was used to analyze the mechanic behaviors of bioceramcis. Using XFEM to simulate the crack propagation path when porosity and the position of the holes are different, and then found that the propagation of the crack can accelerate the degradation of the bioceramic but it also may cause the failure of the structure.