Numerical and Experimental Characterization of Hybrid Fastening System in Composite Joints

Document Type

Contribution to Book

Publication Date


Publication Title

Proceedings of the Annual Conference on Experimental and Applied Mechanics






Drilling of holes in continuous fiber composites for fastening reduces the load carrying capacities, introduces delamination and creates sites for failure initiation and progression. Recent work on a novel hybrid fastening system, which introduces a structural resin insert through a channel in the bolt shaft, overcomes the effects of drilling, eliminates slip, reduces delamination and increases the load-carrying capacities. While the benefits of this system are experimentally observed, the phenomena that govern these improvements are not fully understood. In this work, numerical simulations and experimental tests of hybrid fastening systems comprised of glass fiber reinforced polymer (GFRP) composite substrates fastened using a ½″ Grade 5 bolt, and with a preload torque of 35 N-m were performed. The results were compared one to the other for stiffness and strength. The simulations captured the damage initiation and progress around the hole, and showed the reduction in bolt tilt ascribed to the incorporation of the adhesive insert. Overall, numerical simulations show promise in providing quantitative information about these complex phenomena, and such post-experimental validations can be used as powerful design tools.