Publications Details

Cohesive zone models for reduced-order fastener failure

Reeder, Brett; Grimmer, Peter W.; Emery, John M.

Joining technologies such as welds, adhesives, and bolts are nearly ubiquitous and often lead to concentrated stresses, making them key in analyzing failure of a structure. While high-fidelity models for fasteners have been developed, they are impractical for use in a full system or component analyses, which may involve hundreds of fasteners undergoing mixed loading. Other failure models for fasteners which use specialized boundary conditions, e.g., spot welds, do well in replicating the load-displacement response of a fastener in a mesh independent manner, but are limited in their ability to transmit a bending moment and require constitutive assumptions when there is a lack of experimental data. A reduced-order finite element model using cohesive surface elements to model fastener failure is developed. A cohesive zone allows for more explicitly representing the fracture of the fastener, rather than simply specifying a load-displacement relationship between two surfaces as in the spot weld. This fastener model is assessed and calibrated against tensile and shear loading data and compared to a traditional spot weld approach. The cohesive zone model can reproduce the experimental data, demonstrating its viability as a reduced-order model of fastener behavior.