Analysis of strain energy release rate based on nonconforming generalized mixed element postprint

Abstract: In order to improve the model combining displacement finite element method and virtual crack closure technology to solve the problem of low accuracy of strain energy release rate, the nonconforming generalized hybrid method and virtual crack closure technology are fused, and a nonconforming generalized mixed element method for calculating the strain energy release rate of cracked plate structure is proposed. The connection between nonconforming generalized mixed element method and virtual crack closure technology is simple and intuitive. The incompatible generalized mixed element method can introduce the displacement boundary conditions and stress boundary conditions of the finite element model at the same time. The finite element model is rational and objective, and avoids the disadvantages of instability caused by the existence of zero elements on the diagonal in the traditional mixed method. On the other hand, the linear equations of this method can share the same solver with those of the displacement finite element method, and the numerical results are stable. Theoretically, the numerical results of displacement, stress and nodal force obtained by this method will be more accurate. The analysis of numerical examples shows that the numerical results of strain energy release rate obtained by the integration of nonconforming generalized mixed element and virtual crack closure technique converge stably and reliably, and the accuracy of numerical results is better than that of nonconforming displacement element method under the same grid density.