Microstructure‐Based Numerical Modeling and Experimental Analysis of the Effect of Fiber‐Matrix Separation in Glass‐Reinforced Polyamide‐6 Forged Components

ABSTRACT This study investigates the structural behavior of a glass‐fiber reinforced polyamide‐6 forged part using numerical simulation methods that replicate the microstructure created by the fiber‐matrix separation (FMS) phenomenon. A numerical “as‐designed” (idealized) model of a T‐beam loaded in three‐point bending, which assumed uniformly distributed fibers throughout the part, overestimated stiffness and strength of the experimental results by 106% and 86%, respectively. Process‐Property‐Structure‐Performance relationship consideration importance was highlighted in this work. The “as‐manufactured” numerical model, based on the real fiber content in each region studied by microstructural analysis, was validated with experimental three‐point bending tests predicting only 2% of deviation in stiffness. However, fiber distribution can be neglected when modeling strength in “as‐manufactured,” as failure in experimental T‐beams consistently initiated at the fiber‐free tip of the rib and propagated catastrophically through the rib area.