Shear performance assessment of repaired honeycomb sandwich composite panels: An experimental and numerical study

Abstract This article presents an effective test method for evaluating the shear performance of repaired honeycomb sandwich panels consisting of glass fiber/epoxy matrix skin and Nomex honeycomb core. Addressing the insufficient research on the shear performance of honeycomb sandwich panels after repair in existing literature, this study conducted mechanical performance tests on the honeycomb sandwich panels before and after repair using the picture frame test method. Surface strain measurements are obtained using digital image correlation (DIC) techniques, and load–displacement and shear stress–strain curves are generated from the experimental results. The study concludes that the repair method utilized in this investigation is effective in restoring the mechanical properties of the sandwich panels. In addition, finite element models of the honeycomb sandwich panels before and after repair are established, and a comparative analysis is conducted between the experimental and simulation results. The study examines the shear modulus, ultimate load, and failure mode of the repaired and unrepaired specimens. The findings verify the feasibility of the picture frame test method for evaluating the shear performance of honeycomb sandwich panels. This study provides valuable insights into the design of shear performance repair for honeycomb sandwich panels and offers theoretical support for material recycling.