Study on Shear Fatigue Performance of Scarf Repaired Honeycomb Sandwich Structure

Abstract

The shear static and shear fatigue tests of the honeycomb sandwich composite were carried out to study the effects of three different repair methods on shear fatigue performance: the unilateral panel scarf repair, the unilateral panel and core scarf repair, and the bilateral panel and core scarf repair. The stress ratio R=0.1 was selected. The results show that the failure mode of the honeycomb sandwich structure is the destruction of the honeycomb core. The structure is torn into two halves from the core, and the core tends to squeeze to one side. There is no debonding between the panel and the core, and no delamination in the panel. The static strength, fatigue limit, fatigue life and residual strength of the specimens are significantly decreased by the scarf repair. The rank of reduction from most to least is: the unilateral panel scarf repair, the bilateral panel and core scarf repair, and the unilateral panel and core scarf repair.And the latter two are remarkably similar.