Power Law Model for Coarse-grained Materials
Coarse-grained materials usually show softening and dilatancy properties during triaxial tests,but the practical hyperbolic model can not reflect these proterties.Power law model can describe both strain-hardening and strain-softening behaviors,which can be used effectively to model stress-strain relationship of coarse-grained materials.The advantage of power law model is that it can simulate a hyperbolic shape up to the peak deviator stress and then simulate post peak softening.The stress-strain and volumetric strain properties of coarse-grained materials during shearing process were depicted.Then the theory and property of power law model were introduced.A power law model for coarse-grained materials is proposed based on concept of power law model.The proposed model not only can simulate strain-hardening and strain-softening behaviors but also can reflect dilatancy property.The tangent Young's modulus and tangent bulk modulus are deduced based on the presented model.Finally the rationality of proposed model is validated based on results of an engineering example.