Mechanical performance of repaired sandwich panels: Experimental characterization and finite-element modelling

Abstract

This paper describes the static performance of adhesively bonded repairs on sandwich panels made with carbon-epoxy composite skins and a Nomex core. First, the mechanical behaviour of pristine and repaired panels under tensile loading was studied. All tests were conducted under room temperature conditions. Then, finite-element analyses were performed to predict the behaviour of repaired panels. Two material models were developed for the adhesive joint: one was linear elastic and the second was elastic-plastic with a shear failure criterion. For the composite skins, an orthotropic linear elastic model was used. Numerical model predictions are in good agreement with the experimental results. It was found also that the strength recovery of the repaired structure increases with the decrease of the scarf angle.