Abstract：To research the first kind of fracture modes in concrete solid，a new method with inner softening bands in element is adapted in this paper. The formulas needed in the three-dimensional model are deduced, including the stress and displacement on the fracture surface. The nodes with the effect of fracture are also discussed. Based on the virtual work principle，the equilibrium equations of FEM considering the effect of fracture are established. Numerical results are listed to demonstrate the accuracy of the program and the rationality of the proposed method.
