EFFECT OF KEY DESIGN VARIABLES ON ADHESIVELY BONDED JOINTS WITH ADDITIVE MANUFACTURING SUBSTRATES

This research study investigates on the effect of key design variables on adhesively bonded single lap joints and the FE modelling of an aluminum additive manufacturing (AM) automotive joint using commercially available finite element software like HYPERMESH and ABAQUS. The main objective is the realization of a reliable finite element model able to simulate the mechanical behavior of a complex bonded joint configuration, assembled to the structure with injected adhesive in static conditions. The effect of key design variables for Single Lap Joints (SLJs) is analyzed with analytical models like the ones provided by Volkersen and Goland Reissner. Then, the effect of adhesive thickness and overlap length on the overall mechanical properties of the 3D printed aluminum SLJ is discussed by assessing the optimal design choices for the sample automotive bonded joint. Numerical results from cohesive FEA modeling are compared both with classical analytical models and validation test data are given. In order to assess the proper parameters to describe the mechanical behavior of the adhesive, also AM Double Cantilever Beams (DCBs) have been considered to evaluate the fracture toughness properties for the development of the joint simulation. The test samples are all bonded using the same commercially available single-part epoxy. Accordingly, after having characterized the adhesive, the additive manufacturing automotive joint FEA model can be assessed.