Why should hole filling fasteners, like MS20470 rivets, not be used in composite structures?

Using hole filling fasteners, such as MS20470 rivets, in composite structures can lead to delamination of the composite materials. Composites often consist of layered materials that are bonded together, and introducing a rivet through these layers can create stress concentrations at the fastener's entry point. If the fastening process generates excessive localized heat or mechanical stress, it can compromise the integrity of the bond between the layers, resulting in delamination. This is particularly critical in composite structures where maintaining the material’s structural integrity is essential for performance and safety.

The other factors, such as weight, installation difficulty, or shear strength, are not the primary concerns regarding the utilization of these fasteners in composites. While these aspects could be relevant in other contexts, the key issue with composite structures specifically relates to the risk of causing delamination, making it imperative to choose fasteners designed to accommodate composite material properties without compromising their structure.