Experimental Investigation of the Polyurethane Foam Cross-section Effect on the Quasi-static Lateral Compression Process

This paper studies the effect of geometrical shape of the polyurethane foam cross-section under the lateral compression on the energy absorption capability, specific absorbed energy, mean force and maximum lateral force, in the quasi-static condition by the experimental method. For this purpose, some polyurethane foam specimens were prepared with the different shapes of cross-section such as equilateral triangle, rectangle, square, equilateral hexagon, and circle. All the specimens have the same cross-sectional area, length, density and mass. The experiments were performed by a DMG machine, Model 7166 by compressing the foam samples between two rigid platens, laterally. The experiments indicate that the specimens with the square and equilateral hexagonal cross-sections have the best energy absorption performance; and the equilateral triangular specimen has the worst energy absorption behavior. Also, there is an interesting order among the values of investigated parameters such as total absorbed energy, specific absorbed energy (SAE), and mean and maximum lateral load which sorted from the minimum to maximum: equilateral triangular cross-section, circular crosssection, equilateral hexagonal cross-section, and finally, square cross-section. Another attractive phenomenon is observed in comparison of two specimens with the rectangular cross-sections which laterally tested in two different directions, longitudinal and latitudinal sides of cross-section. The comparison shows that the SAE by the longitudinal side compressed specimen is higher than the latitudinal side compressed specimen; but, the mean and maximum lateral loads have an inverse trend.