Experimental and numerical analysis of the shear nonlinear behaviour of Nomex honeycomb core: Application to insert sizing

International audienceThis work is a contribution to the understanding of the nonlinear shear behaviour caused by cell postbuckling inNomex honeycomb cores. First, an experimental benchmark study was made of different designs for the sheartesting of honeycomb cores. Then, several test specimens were fabricated and tested, a 3D DIC system being usedto measure and record the displacements. An Artificial Neural Network (ANN) was also used to identify the onsetof bucking and collapse of the cells. The influence of the overall boundary conditions of shear tests on thebuckling of the cells is presented both experimentally and numerically. The reversibility and test procedureresults suggest that it may be possible to allow the shear strength to be increased by up to 35% under certainconditions