Effect of Core Height Ratio on Drop Weight Impact Properties of Double Layer Honeycomb Core Sandwich Panels

Abstract

A honeycomb core sandwich panel (hereafter, HSP for brevity) is superior in impact absorption under whole surface compression, because of the buffer effect of core. However impact properties of HSP under local compression such as drop weight impact are affected by the plate as the face sheet in addition to the core layer. This research describes drop weight impact properties of double layer HSP which consists of two core layers and three plates. In order to build up the experimental database for design of double layer HSP, a series of drop weight tests was carried out by using double layer HSPs with the several ratios of the core heights. From obtained results, the follows were summarized: 1) Two or three peaks of the load appeared in the load-displacement curve. The peak loads were larger in sequence of their appearances.2) In the load-displacement curve until the last peak of the load, there are load increase regions by deep drawing of the plates and load equilibrium regions similar to plateau region under whole surface compression. 3) When the height of the upper layer core was lower, the absorption energy was larger in total. 4) An energy absorption model has been developed and verified for design of double layer HSP.

Estimation method of support reaction on face sheet of sandwich panel by inverse analysis of deformed shape data

“…On the other hand, when local compressive load such as drop weight impact is vertically applied on the face sheet of the sandwich panel, the face sheet will be deflected and the core layer will be crushed near the point of action at relatively low load (Rathbun, et al, 2006;Kobayashi, et al, 2015). Then the face sheet is supported by the core layer (Kishimoto, et al, 2012(Kishimoto, et al, , 2013. Therefore, in order to evaluate the mechanical property of the sandwich panel subjected to the local compression, it is important to estimate the distribution of the support reaction by the core layer.…”