Experimental Investigation of the Effect of Circular Cutout Trigger on Energy Absorption of Three-layered Steel/Polypropylene/Aluminum Deep Drawn Cups

In this paper, energy absorbing characteristics of aluminum/polypropylene/steel sandwich cups are investigated. To this end, sandwich panels were fabricated using hot pressing technique. Then the panels were deep drawn using a circular punch to produce three-layer cups. Subsequently, the cups were axially compressed (crushed) under quasi-static deformation in order to investigate their energy absorption capacity. Finally, the effects of thickness of polypropylene layer as well as circular cutout triggers on energy absorption of the sandwiched cups were evaluated. The results show that changing the thickness of polypropylene layer from 1 to 2mm could successfully increase the energy absorption by about 24%. Furthermore, adding geometrical triggers like circular cutouts with radius of 2.5 mm could reduce the absorbed energy from 346J in the sample without trigger to about 335J in the sample with trigger (3.2% reduction). The trigger could also reduce the peak force near 14% (from about 29kN to about 26kN) that can be considered as a positive point of triggers to mitigate damage in the samples.