Strength assessment of fiberglass layer configurations in FRP ship materials from yard practices using a statistical approach

Fiberglass Reinforced Polymer (FRP) is a type of composite extensively used in small boats in Indonesia. Most FRP research focuses on general applications and research on FRP materials is not aligned with actual yard practices in lamination. This study examined the mechanical characteristics of marine-grade FRP composites applied to ships, considering fiberglass layer configurations that conform to yard practices and their compliance analysis with several international classification rules. Samples from Bojonegara and Makassar 3 met the criteria of the Indonesian Classification Bureau, Korean Register, and American Bureau of Shipping rules for tensile and bending strength and have the best specific strength. Analysis of Variance showed that the differences in fiberglass layer configurations had a significant impact on tensile and bending strength. Grouping using Tukey Simultaneous Tests indicated that samples with four or five layers showed tensile and bending strength that were not significantly different statistically. The Unsaturated Polyester Resin brand had a considerable impact on tensile strength but a less pronounced effect on bending strength. Sample Bojonegara and Makassar 3 can be recommended for practitioners in FRP shipyards as they have met the requirements of international regulations.