Influence of Core Density on Flexural Behavior of PUF Cored Sandwich Beams

The present investigation was mainly focus on the influence of high density polyurethane foam core on the flexural behavior of sandwich beams. To rate the performance of these structures, many engineering parameters such as face sheet stress (f), core shear () beam deflection (y) and the most important beam properties i. e. flexural rigidity (D) and Shear stiffness (S) were considered. In order to pursue this task, number of sandwich beam specimens of different core densities (ranged from 50Kg/m3 to 300Kg/m3) were fabricated& tested under both 3-Point and 4- point bending experimentally. The results of both 3-Point and 4- point bending were used to evaluate the mechanical properties using the most popular formulae proposed by Kuenzi (ASTM Standards, C393). Furthermore finite element analysis was performed by modeling the sandwich beams that were considered for experimental study using the validated FEM/ANSYS. From the present investigation it is evident that the performance of high density foams are better than conventional low density foams, because it was observed remarkable improvements on the most important beam properties i. e. flexural rigidity (D) and shear stiffness (S) of sandwich beams. It is also observed that the engineering parameters (f, , y) decreases at constant load as core density increases which indicates that the load bearing capacity of the beam increases. From the present investigation it is evident that tremendous improvements can be achieved on flexural behavior of sandwich beams with the use of high density foam cores (ranged from 200Kg/m3 to 250Kg/m3). However the higher core densities (greater than300K/m3) are unsuitable for cores because the results are nearly asymptote for densities higher than 300Kg/m3.