The structural analysis and strength evaluation of the rivet nut joint for composite repair

Abstract

Fiber reinforced polymer (FRP) composite laminates have become popular for aero-structures and mechanical parts as they are lighter, stronger and tougher than metals. Damage to composite structures reduces their service life. To improve their service life, the damages needs to be repaired so that their structural integrity can be restored. A rivet nut joint is a prominent technique that is used for composite repair when access to only one side of the component is available. In this paper, we test and analyze the strengths of various specimens that are repaired using the rivet nut method. Single lap joint specimens with four different w/d (width to diameter) ratios and three e/d (edge to diameter) ratios were manufactured and tested. Tensile tests were performed on the rivet nut joints and their failure modes were evaluated. Additionally, the failure loads of the rivet nut joints were compared to those from using mechanically bolted joints. Finite element analyses of the rivet nut joints were performed and the stresses around the holes were calculated. Finally, the experimental failure modes and loads were compared with those determined from the finite element analyses. (C) 2015 Elsevier Ltd. All rights reserved.