Fractional order plasticity model for granular soils subjected to monotonic triaxial compression

This paper presents a fractional order plasticity model by using the concept of fractional order plastic flow. The flow direction is obtained by performing fractional order derivative of the plastic potential function with respect to loading stress. Unlike the classical model, the obtained flow direction changes with the changing fractional order, which makes the model capable for modelling various kinds of plastic flow patterns of different granular soils without changing the details of the potential function. The flexible ability of the proposed model is further validated by simulating multiple series of experimental results of different granular soils subjected to drained and undrained triaxial compressions.