Analysis of Hard Point Mechanical Behaviour Due to Variations of Potting Agent Volume on a Composite Sandwich Panel

Abstract

Composite sandwich panels are widely used in lightweight structures, especially in aerospace, automotive, and marine industries. They are chosen mainly because of the superiority of their specific stiffness as compared to solid panels. Stingray, a solar car designed by the UiTM Eco-photon team, applied this technology for its lightweight property. However, the honeycomb sandwich constructions were susceptible to localized load. Thus, load attachment points using metal inserts, also known as ‘hard points’, were introduced. In this study, the behaviour of hard points based on three volume variations of the potting agent was investigated. ESA recommended static pull-out tests to be conducted on the sandwich panels composed of Nomex honeycomb core, two laminates of carbon fibres/epoxy composite as the face-sheets to determine the failure load of the hard points. A finite element simulation using ANSYS was also performed to determine the displacement of the inserts in presence of normal-to-plane load. The results include load versus extension curves obtained by both methods. Potting agents were found to elevate the stiffness and the strength of the inserts by some degree. Therefore, the application of these hard points on the solar car was found to be effective.