Advanced Composites Overview
In many ways fiber-reinforced advanced composites are stronger than metallic structures, but they do not respond well to localized concentrated loading.
Three types of special fasteners have been developed to address this issue and others, such as galvanic compatibility, interference fit, hold edge crushing, vibrations, and water absorption.
The Types
Bonded-On, Bonded Mechanical, and Nonmetallic Potted-In.
The bonded-on type includes studs and insert plates supplied with pre-attached thermoplastic adhesive. The adhesive is melted by applying heat to the fastener.
The bonded mechanical type uses a combination of adhesive and mechanical means for retention in the structure.
The nonmetallic inserts and spacers (sleeves and plugs) are primarily designed for sandwich structure. The primary material is polyetherimide which is non-reactive with current composites and is very lightweight.