Micromechanical simulations of biaxial yield, hardening and plastic flow in short glass fiber reinforced polyamide

• Published in: International journal of mechanical sciences 2011-09, Vol.53 (9), p.696-706
• Main Authors: Selmi, A., Doghri, I., Adam, L.
• Format: Article
• Language: English
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Fundamental areas of phenomenology (including applications); Glass fiber reinforced plastics; Glass fibres; Hardening; Homogenization; Homogenizing; Inelasticity (thermoplasticity, viscoplasticity...); Mathematical analysis; Micromechanics; Orientation; Physics; Plastic flow; Plasticity; Polyamide; Polyamide resins; Polymer industry, paints, wood; Solid mechanics; Structural and continuum mechanics; Technology of polymers; Tensors
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/j.ijmecsci.2011.06.002

Mean-field homogenization (MFH) is used to predict the biaxial yield behavior, hardening and plastic flow of composite materials made of an elasto-plastic matrix reinforced with misaligned short fibers. The procedure is applied to short glass fiber reinforced polyamide, which represents an important industrial application of those composites. First, MFH is verified against full-field accurate finite element simulations of representative volume elements with multiple fibers. Next, a parametric study is carried out with MFH in order to predict the biaxial plastic behavior of numerous microstructures corresponding to various values of volume fraction, aspect ratio and second-rank orientation tensor components of the glass fibers. Results demonstrate the loss of both isotropic hardening and plastic flow normality, except for 2D random orientation. For illustration, a fit of Hill's orthotropic plasticity criterion is conducted for several orientation tensors. ► Micromechanical modeling of thermoplastic polymers reinforced with misaligned short glass fibers. ► Modeling is based on inelastic mean-field homogenization methods. ► Numerical prediction of yield “surfaces”, hardening and plastic flow under biaxial loadings. ► Extensive parametric study of the influence of volume fraction, aspect ratio and orientation tensor components.