Effect of sampling orientation on the mechanical properties of glass fiber reinforced epoxy nanocomposites

Abstract

Fiber-reinforced polymer composites are manufactured using various methods, with vacuum-assisted resin transfer molding (VARTM or VARIM) being a notable technique under extensive scrutiny. This study's primary focus lies in assessing how the orientation of sampling impacts the mechanical properties of both pure and nano-composite materials. 2 wt.% nano Al2O3-doped and non-doped composites were produced using the VARTM process. Tensile, flexural, and density test specimens were extracted from three distinct zones: those aligned horizontally to the resin flow (HRF) and those oriented vertically to the resin flow (VRF). Remarkably, experimental results revealed that values obtained from samples in the third zone, specifically on the vacuum outlet side, were up to 3.91% higher when compared to the others. Notably, VRF samples consistently outperformed their HRF counterparts. To determine whether these results held statistical significance, a one-way ANOVA analysis was conducted. Although the results didn't show any significant statistical differences, it's still crucial to be careful about how you select the sample orientation in experimental studies. To enable a more precise comparison of stress values across various plates, it is important to extract samples with uniform orientation and from consistent zones.