Experimental modal analysis of glass and laminated glass large panels with EVA or PVB interlayer at room temperature

Abstract

Laminated glass is used for fail-safe structures in many fields of engineering. It contains a polymeric interlayer that improves the brittle glass behavior after fracture, provides damping, increases impact resistance, and at the same time maintains transparency. This paper examines the effect of the type of the interlayer on laminated glass oscillation using a roving hammer test. It also compares the modal response of the laminated glass before and after the low-velocity impact. The experimental modal analysis is validated by numerical modal analysis and using a different experimental methodology. This contribution discusses natural frequencies and damping ratios affecting the impact response and the reduction of noise and vibrations. It is found that the inserted polymer foils increased the damping and the impact resistance of the transparent plate. The interlayer with a higher ratio between loss and storage modulus showed higher damping and thus energy dissipation potential. No significant difference was measured in the natural frequencies of laminated glass before and after low-velocity impact. Inferences drawn from this study can be used by engineers, architects, and contractors when selecting suitable panels for applications such as windshields or curtain walls.