Evaluation of Flexural Rigidity of PU - foam Cored Sandwich Structures

Abstract

Flexural properties form crucial role in evaluating the lightweight sustainable structures against bending loading. Researchers are working on fabrication of new composites materials worldwide to enhance the applicability of these materials. Glass fiber reinforced polymer composites is widely used many industrial application particularly in the automotive industry due to advantages such as low weight, ease of processing, price and noise suppression. Sandwiched structure forms a new option for automotive industry. A sandwiched structure is a special type of sandwiched–structure composite that is fabricated by attaching two thin but stiff skins to a light weight but thick core. The core material is normally low strength material, but its higher thickness provide the sandwiched structure composite with high bending stiffness with low overall density. Keeping this in mind our present study concern about the preparation of sandwich composites by using glass fibre as skin and polyurethane foam as a core material and sample was prepared by hand layup method for two different thickness of the core which influence greatly on the mechanical properties of material. Testing of samples according to ASTM standard was done and phenomenal observations are accurately noted and results are tabulated. The qualitative comparison has been made to samples of different thickness to recommend the applicability of sample. It was observed that remarkable changes have been recorded as thickness of the sandwich affects greatly on resistance to bending, which is because of core material sustain greater value of load with its increased load bearing area. The experimental reading has been tabulated for all the loading conditions and performance oriented comparison is highlighted to show case the reasonable factor for the drastic changes under flexural loading conditions.