Micromechanics modelling of graphene platelets reinforced polymer composite materials with imperfect interfaces

This work investigates the elasto-plastic response of platelets-like inclusions reinforced polymer composites showing an imperfect interface. The solution of the heterogeneous material problem is solved through a kinematic integral equation. To account for the interfacial behaviour, a linear spring model LSM is adopted, leading to an expression of the modified Eshelby's tensor. As a consequence, the interfacial contributions with respect to the strain concentration tensor within each phase as well as in the average strain field are described by a modified version of the Mori-Tanaka scheme for the overall response. The non-linear response is established in the framework of the J2 flow rule. An expression of the algorithmic tangent operator for each phase can be obtained and used as uniform modulus for homogenisation purpose. Numerical results are conducted on graphene platelets GPLreinforced polymer PA6 composite for several design parameters such as GPL volume fraction, aspect ratio and the interfacial compliance. These results clearly highlight the impact of the aspect ratio as well as the volume fraction by a softening in the overall response when imperfection is considered at the interface. Present developments are analytical-based solutions. They constitute a theoretical framework for further multi-scale applications in automotive. The crashworthiness simulation incorporating an influence of the interfacial behaviour on the strain energy absorption SEA is of interest.