Experimental and Numerical Investigation of Free Vibration Behaviours of Sandwich Syntactic Foams

Abstract

The studies on the development of new composite materials that are lighter and have high strength and rigidity are increasing with the developing technology in recent years. Among these new technological materials, syntactic foams are polymer structures fabricated by dispersing low-density hollow particles (microballoons-MB) in a matrix material. Because of its advantages, syntactic foams are widely used in the automobile, marina, and aerospace industries, and it is very important to investigate the vibration behaviour in the design process. There are limited studies in the literature on the numerical and experimental free vibration analysis of syntactic foams. In this study, the vibration characteristics of sandwich syntactic foams were numerically and experimentally investigated. First, the differential equations of the sandwich syntactic foam beams were derived according to higher-order shear deformation theory (HSDT). Numerical analysis was carried out using the finite element method written in MATLAB. Then, to prove the accuracy of the present numerical model, the natural frequencies are compared with the experimental results. Then, the present numerical model was validated by comparing it with the experimental results. Since the numerical model was validated, the effects of varying the MB volume fractions and MB density on the vibration behaviour of the sandwich syntactic foams were investigated. Thus, according to the authors' knowledge, the HSDT-based FEM and experimental method were used for the first time to study the vibration analysis of sandwich syntactic foams. The authors aimed to contribute in this regard.