Experimental investigation of an alternative approach to temporarily repair Nomex honeycomb sandwich structures in aerospace applications

Abstract

In this study, the effectiveness of an alternative approach to temporarily repair an open-hole damaged Nomex honeycomb sandwich structure is experimentally investigated. The repair process consists of a resin-infused carbon fabric wet layup patch adhesively bonded to the facesheets and Airex structural foam used as a core replacement plug. The specimens of intact, damaged and repaired Nomex honeycomb sandwich panels are subjected to the quasi-static three-point bending test. The panel's flexural performances are determined by analyzing the obtained load-displacement responses. The effectiveness of the proposed repair technique is evaluated by comparing the responses of the repaired panels with the ones obtained from the intact and damaged panel specimens. The comparison is effectuated in terms of mean values of flexural elastic modulus, peak force, energy absorption, and specific energy absorption. In addition, the observed failure modes of the different panel configurations are pointed out and discussed.