Influence of sea sand reinforcement on the static and dynamic properties of functionally graded epoxy composites

This study aims to study the static and dynamic properties of the functionally graded epoxy composites with sea sand particles as reinforcement. In this study, functionally graded polymer composites (FGPC) were fabricated by dispersing sea sand throughout the epoxy, exhibiting a spatially varying composition profile within the material. Physio-mechanical properties and high strain rate compression responses were determined for the prepared FGPC by varying the composition of sea sand [0%, 10%, 20%, and 30% (by weight)]. The gradience analysis was performed using the burn-out test and weight method, and the results significantly matched, as well as the variation in gradation could be identified. The density and void content are increased with increased sea sand composition. Tensile and specific strength for neat epoxy shows a 2.41 times increase compared to 30% sea sand-filled epoxy. When loaded from the composite side of FGPC, flexural strength increased by 27.93%, hardness increased by 12.47%, and impact strength increased by 2.35 times for 30% sea sand-filled epoxy compared to neat epoxy. Under dynamic compression loading, FGPC was subjected to split-Hopkinson pressure bar experiments for neat and filled epoxy. These samples were deformed at strain rates in the 10³ s⁻¹ while subjected to pressures of 2, 3, and 4 bar. Stress–strain curves and the strain rate were computed using the raw data. High strain rates improve compressive strength, which increases exponentially as the strain rates increase. Scanning electron microscopy micrographs of the fractured specimen are employed to analyze the fracture characteristics.

Graphical Abstract