Computational Analysis of the AFM Specimen on Mixed-mode Ⅰ+Ⅱ+Ⅲ Fracture

摘要

The computational analysis of an all fracture modes (AFM) specimen on mixed-mode I+II+I1I fracture is presented in this paper. The separated energy release rates (SERRs) along the crack front of the AFM-model are calculated by the modified virtual crack closure integral (MVCCI)-method and the commercially available software ANSYS. A transition model is built by adopting several 3D elements of SOLID45 and one point element of MASS21 in the ANSYS program. Under the related constraint conditions, the separate force and moments are respectively applied on the point element of the transition model, so the corresponding desired reaction forces can be obtained. When the desired loads are superimposed and applied on the AFM-model, the mixed-mode I+1I+III fracture can then be achieved. Thereby, the SERR results are calculated. The calculation results show that the facture behavior of G_Ⅱ and G_Ⅲ appears complex due to the global deformation and Poisson's ratio, although the distribution of SEERs G_Ⅰ is symmetrical with respect to the middle point along the crack front. The total SERRs, G_(Tn)-values increase along the crack front with the minim value at one corner and the maxim value at the other corner. It can therefore be predicted that the fracture will occur initially at one corner on the crack front of the AFM-specimen in this case.