Numerical modelling of mechanical behaviour of model brittle porous materials at the mesoscale

To describe the mechanical response of brittle porous material mesovolumes, the evolutionary approach was applied with considering them as nonlinear dynamic systems. The nonlinear constitutive equations describe damage accumulation and their impact on the degradation of the strength properties of the elastic frame. In the framework of hierarchical modelling, the mesoscale porosity is taken into account explicitly while the smaller pores are taken into consideration integrally as a damage measure. This small scale damage enters in the constitutive equations as dilatancy, including that of the shear nature. Two types of morphology of model porous structures are considered: overlapping spherical pores and overlapping spherical solids. The obtained results of numerical simulation reveal little influence of pore morphology on the characteristics of damage in the frame. The averaged stress-strain diagram appears to be sensitive not only to the value of porosity but also to the pore morphology. The strength limit has a similar dependence.