Micromechanical Analysis of Tensile Failure Mechanisms in Short Glass Fiber‐Reinforced Nylon 6 Syntactic Foams

ABSTRACT Understanding the fracture behavior of short fiber‐reinforced syntactic foams under tensile loading is essential for improving the reliability and structural integrity of these advanced composite materials. In this study, tensile behavior and ductile failure mechanisms of short glass fiber‐reinforced nylon 6 (Ny6) syntactic foams were systematically investigated using three‐dimensional micromechanics‐based finite element analysis (FEA). The simulations provided detailed insights into the complex failure processes governing these thermoplastic syntactic foams. Regions of high tensile hydrostatic stress consistently developed in the matrix near the fiber tips, regardless of microsphere content. Both the glass fibers and microspheres exhibited a low probability of fracture. The failure was primarily governed by matrix failure, initiated by microvoid nucleation at fiber tips. Damage subsequently propagated along the fiber–matrix interface, inducing localized plastic deformation in narrow matrix regions. This facilitated interfacial failure between adjacent fiber tips and between opposing poles of neighboring microspheres, followed by matrix tearing and fiber slippage. Ultimately, a ductile crack grew to a critical size, triggering a transition to brittle fracture and leading to the complete collapse of the syntactic foam.