Experimental investigation of Lightweight Sandwich Structures Made of Expanded Perlite/Expanded Polystyrene/Epoxy Foam Core and Formica Sheet as Skin

Abstract

Lightweight sandwich composites are widely employed in various technical applications. A lightweight sandwich structure encloses a lightweight core with two external layers known as skins. Due to sandwich panels' inherent light weight, high load capacity, and relatively high compressive and flexural strength and stiffness, their use increased significantly in aerospace, automobile, offshore construction, and many more industries. Moreover, it provides a higher strength-to-lightweight ratio, which is essential for these industries. As these sandwich composite structures are a mixer of several materials, they combine the positive properties of individual materials, offering advantages like better fuel efficiency, higher structural integrity, and improved noise reduction. Driven by the need for energy-efficient solutions and improved performance across industries, the demand for these composite structures is growing based on economic and technical factors. Perlite has low density, dimensional stability, easy processing, and environmental benefits which makes it beneficial for constructing sandwich composite structures. The flexural and compressive properties are investigated along with the varying core density and different mixing ratio between EPS and EP. The performance of light weight the sandwich structure in flexure in compression is affected by the amount of perlite. The load-carrying capacity of the sandwich structure was increased about 3.26-4.26 times and 8.61-12.33 times in flexural strength and compressive strength respectively, with an increasing a density that ranged from 0.176 to 0.454 g/cm3 . The prepared samples' density seemed to somewhat increase with the addition of EP while decreasing with the addition of EPS. The density of the sample with an EPS core alone was found to be 0.176 g/cm3, which is 61.25% less dense than the sample with an EP core. The flexural failure of the sandwich composite was initiated from the core of the flexuralspecimen (core shear failure) and then delamination of the skin. During compression, the strength and the energy absorption are both enhanced significantly by the increment the of the amount of perlite and EPS. This research uses an EP/epoxy core with a portion of EPS and Formica sheets serving as the skin to create a lightweight sandwich construction. For various EPS and EP mixing ratios, the mechanical characteristics of the sandwich panels, including compressive strength, modulus, energy absorption, and failure modes, are investigated.