Modeling Progressive Failure of Bonded Joints Using a Single Joint Finite Element

Enhanced finite elements are elements with an embedded analytical solution that can capture detailed local fields, enabling more efficient, mesh-independent finite element analysis. In the present study, an enhanced finite element, referred to as a bonded joint element, that is capable of modeling an array of joint types is developed. The joint field equations are derived using the principle of minimum potential energy, and the resulting solutions for the displacement fields are used to generate shape functions and a stiffness matrix for a single joint finite element. This single finite element thus captures the detailed stress and strain fields within the bonded joint, but it can function within a broader structural finite element model. The costs associated with a fine mesh of the joint can thus be avoided,whilestillobtainingadetailedsolutionforthejoint.Additionally,thecapabilitytomodelnonlinearadhesive constitutivebehaviorhasbeenincludedwithinthemethod,andprogressivefailureoftheadhesivecanbemodeledby using a strain-based failure criteria and resizing the joint as the adhesive fails. Results of the model compare favorably with available experimental and finite element results.

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