Computational and Experimental Characterization of Continuously Fiber Reinforced Plastic Extrusions: Part I – Short-Term Flexural Loading

Abstract

Experimental characterization of time-independent properties for rectangular hollow-cored continuous fiber reinforced commingled recycled plastic extruded forms under short-term flexural loading has been presented in this paper. Finite element based computer models have been developed to predict the effects of damage progression in such reinforced extruded plastic forms. Experimental results demonstrate that fiber micro-buckling and fiber–matrix interface failures occur during the static flexural loading environment. Experimental data also indicates that these damage modes significantly reduce the short-term flexural properties and should be avoided or minimized through optimizing the location of continuous reinforcement and using a coupling agent in enhancing interfacial bonding between reinforcement and matrix. “Damage dependent” finite element models were developed using different material property types to represent the glass-fiber roving, fiber–matrix interface and plastic matrix respectively. Material nonlinearity of the plastic matrix has been incorporated along with stress-based failure criteria to account for fiber–matrix interfacial shear failure and local fiber micro-buckling. A user-defined subroutine, part of an industry standard finite element software package, has been modified to accommodate the damage progression. The developed finite element based model(s) have correlated well with the short-term test results, and can provide a “design tool” in predicting fiber micro-buckling and fiber–matrix interfacial shear failure associated with future to-be-studied composite extrusions/forms under short-term loading.