Shear behaviour of sand-rubber mixtures: interpretation from energy transformation and force chain evolution

This study investigates the effect of rubber particles on biaxial shear responses of sand-rubber mixtures (SRMs) using a multibody mesh-free method, which enables the flexible and robust modelling of visco-elastic deformation of rubber particles. From the energy evolutions in SRMs with different rubber contents (RCs), including the incremental elastic strain energy, friction slipping dissipation and damping dissipation, it is found that the slipping dissipation is much more severe than damping dissipation for specimens with lower RC, but less significant for specimens with greater RC during shearing. In addition, the fraction of incremental strain energy increases with RC. Further investigations on the evolutions of force chain networks of SRMs indicate that the incorporation of rubber particles facilitates the stability of strong force chains by mitigating particle rotations in the strong force chains and relative sliding in the weak contacts. It is observed that the energy transformation in sheared SRMs has a strong correlation with their microstructural evolution.