Numerical analysis on failure behaviour of polyurethane polymer concrete at high strain rates in compression

Experimental investigation on dynamic compressive behaviour of polyurethane polymer concrete (PPC) by a Split Hopkinson Bar (SHPB) system showed that the dynamic compressive strength of PPC material increased firstly and then decreased with the increment of strain rates. In order to demonstrate the novel dynamic compressive behaviour of the PPC material, a 2D FE mode of a SHPB system is developed, the heterogeneous mesoscale model of the PPC specimen included. In the mesoscale model, the PPC sample is modelled as a three-phase composite consisting of aggregate, polyurethane polymer matrix and the aggregate/matrix interface. The aggregate is modelled as arbitrary polygon with irregular shape. The interface is assumed as a thin boundary layer around the aggregate with given geometry and mechanical properties. Numerical simulations of the PPC specimens in compression under different strain rates are performed by an explicit numerical approach based on LS-DYNA codes. Failure factures of PPC material in mesoscale level are analyzed numerically. It is found that the novel dynamic behaviour of the new composite attribute to the damage and failure features of the interface and the elastic-plastic properties of the polyurethane polymer matrix.