Abstract
With a classical notched configuration, the damage process in the transverse plane of fiber-reinforced polymer composites are studied by a direct numerical simulation model (DNS). However, to avoid high computational costs the region in which the fiber/matrix microstructure is explicitly modeled must remain small. Therefore, away from the notch tip, a homogenized model is needed to capture the far-field mechanical response without damage but with possibly rate-dependent nonlinearity. In this contribution, with a representative volume element (RVE), a step-by-step numerical homogenization procedure is introduced to calibrate a homogenized viscoelastic-viscoplastic (VE-VP) model with the same formulation as the VE-VP model used for describing the polymer behavior in the RVE model. The calibrated VE-VP model is used in a homogenized FEM model to describe the composite material response and compared against the RVE model. It is found that: (1) the homogenized model captures the viscoelastic deformation, the rate-dependent yielding, stress relaxation and unloading behavior of the polymer composite well, although the assumptions of a single plastic Poisson's ratio and pure isotropic hardening are oversimplifications of the composite behavior; (2) the novel step-by-step numerical homogenization procedure provides an efficient and accurate way for obtaining material parameters of a VE-VP model.
Original language | English |
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Article number | 112690 |
Journal | Composite Structures |
Volume | 252 |
DOIs | |
Publication status | Published - 15 Nov 2020 |
Keywords
- Composites
- Numerical homogenization
- RVE
- Viscoelasticity
- Viscoplasticity