Compressive Strength and Elastic Modulus of a 3D Woven Glass/Polyester Fire-Retardant Sandwich Composite

A 3D woven sandwich composite structure has been widely used in various fields due to its advantages in terms of its strength-to-weight ratio. The adoption of lightweight materials in the railway industry for train carriages is aligned with United Nations Sustainable Development Goal 11, as this fosters the development of sustainable transportation by reducing carriage weight, enhancing fuel efficiency, minimizing component wear, and mitigating air pollution. This study explores the effect of the addition of aluminum trioxide (ATH) filler on the core structure, density, compressive strength, elastic modulus, and the number of added layers of 3D woven core fabric with 2D woven face sheets. Sandwich composites were produced with varying ATH loads of 30%, 40%, and 50%. We also varied the number of 3D woven core fabric layers in the composite sandwich (one, two, three, and four layers) and the 2D preform (one on the upper side, two on the upper side, and one on the upper + two on the lower sides) used as a face sheet thickener. The results showed that the addition of ATH filler increased the composite density. The addition of up to 40% ATH improved the strength and elastic modulus of the composite, while excessive loading led to a decrease in both properties. Variation of the 3D and 2D preform layers also improved the compressive strength and elastic modulus. We conclude that 3D woven sandwich composites incorporating 40% ATH, multilayered 3D woven core fabric, and 2D woven fabric face sheet thickener represent promising materials for use in the railway industry.