Finite element analysis (FEA) applied to polyethylene foam cushions in package drop tests

Two designs of polyethylene (PE) foam cushions were compared, using a rigid 'product' of mass 5.6 kg, and an outer corrugated fibreboard box. The acceleration-time history for the product was measured when the box was dropped flat from 1 m onto a rigid floor. The data was processed to calculate the impact force as a function of the packaging deformation. Finite element analysis (FEA) predictions of the impact force vs. package deflection were accurate for end-cap designs using Ethafoam, but underestimated the slope of the experimental force vs. deflection relation for corner-cap designs. The corner-cap design is more efficient in reducing the peak product acceleration for multiple impacts. The contribution of the corrugated board box to the impact response appears to be small. The FEA results were compared with those from the cushion curve design method and were found to better predict the performance of complex shaped cushions. Copyright (C) 2004 John Wiley Sons, Ltd.