Experimental evaluation of the crush energy absorption of triggered composite sandwich panels under quasi-static edgewise compressive loading

An experimental evaluation of the energy absorption of constrained triggered sandwich structures is presented. Four configurations of embedded ply-drop triggering mechanisms were analysed and compared. A composite pi-joint was then developed to provide a constraint fixture that is representative of an in-service integrated energy absorbing structure. The specimens tested within the pi-joints obtained slightly lower specific energy absorption compared to the equivalent specimens tested in a rigid test fixture. The potential of an integrated energy absorbing triggered sandwich structure contained within a composite pi-joint was demonstrated. The interface between the sandwich panel and the pi-joint was not bonded, and further research will focus on the development of a bonded joint configuration suitable for structural applications.