Efficient non-iterative modelling of pressure-dependent plasticity using paraboloidal yield criterion

A full understanding of the non-linear mechanical response of the polymer is essential for fibre-reinforced polymer composite design because an explicit definition of constitutive material models for the constituents (fibres, matrix, and interface) are prerequisite in micromechanical simulations. Unlike ductile metals, the material behaviour of polymer matrix is characterised by plasticity theories influenced by a combination of distortional and spherical energy dissipation. In this respect, an elastoplastic thermodynamic continuum model derivation is proposed using the paraboloidal yield criterion under isothermal conditions. A non-iterative scheme is developed for the numerical computation of the plastic strain increment multiplier. Both associated and non-associated flow rules are investigated following classical plasticity loading-unloading conditions. It thereby, evades conventional computationally demanding iterative process by replacing it with an exact determination of plastic strain increment. This novel approach highly improves the computational efficiency algorithmically. The real-sized numerical models are investigated and the comparison between simulated and experimental results shows the reliability and unprecedented accuracy of the proposed elastoplastic mathematical model.

Automated summary

A full understanding of the non-linear mechanical response of polymers is crucial for the design of fibre-reinforced polymer composites. This study proposes an elastoplastic thermodynamic continuum model based on the paraboloidal yield criterion, which avoids the computationally demanding iterative process and improves computational efficiency algorithmically. The reliability and unprecedented accuracy of the proposed model are demonstrated through the comparison between simulated and experimental results.