Pengaruh Ketebalan Core dan Jumlah Layer Skin terhadap Kekuatan Bending Komposit Sandwich Skin Fiberglass dengan Core Kardus Tipe A-Flute

Abstract

Sandwich composites are lightweight structural materials with a high strength-to-weight ratio and have potential as alternatives to conventional materials. This study aims to analyze the effects of core thickness variation and the number of skin layers on the bending strength of fiberglass-skinned sandwich composites with an A-flute cardboard honeycomb core. The research employed an experimental method using three-point bending tests in accordance with ASTM C393. Core thicknesses of 10 mm, 20 mm, and 30 mm were investigated, while the number of fiberglass skin layers was varied at 1, 2, and 4 layers. Bending strength was evaluated based on core shear strength and skin bending stress, expressed in MPa. The results show that the highest average core shear strength was obtained at a core thickness of 10 mm with 4 skin layers, while the lowest value occurred at a core thickness of 30 mm with 1 skin layer. The highest skin bending stress of 43.40 MPa was achieved by the specimen with a 10 mm core thickness and 1 skin layer, whereas the lowest value of 11.83 MPa was observed at a 30 mm core thickness with 4 skin layers. These results indicate that increasing core thickness tends to reduce bending strength based on core shear strength, while increasing the number of skin layers enhances the bending performance of the sandwich composite, and an interaction effect between the two variables is present.