2.5D finite element algorithm based on Drucker-Prager yield criterion

This note regards the embankment as an ideal elastic -plastic material, and introduces the Drucker -Prager yield criterion into 2.5-D FEM. Firstly, the pure elastic trial stress is applied, and the Drucker -Prager yield criterion is used to determine whether yielding will occur or not. Then, the backward Euler integration method and the tangent stiffness method are used to derive the consistent tangent modulus matrix, after which the iterative correction of plastic deformation is realized. Finally, an elastoplastic 2.5D FEM is proposed according to the procedures. Compared with the measured values and existing results, it was found that the elastic -plastic 2.5-D finite element algorithm proposed in this note has good consistency with the measured values. Due to the consideration of the plastic deformation of the foundation soil induced by train moving loads, the present results are slightly larger than those of existing elastic methods.