Numerical modeling of adhesive flow and structural deformation during hybrid bonded-bolted joint assembly: validation against experimental data

This paper presents the experimental validation of the computational model previously developed by the authors for simulating the assembly process of hybrid bonded–bolted joints (HBB) with liquid adhesives. The model describes the coupled fluid–structure interaction during assembly by combining a quadratic programming formulation for structural contact with a Reynolds equation–based lubrication model for adhesive flow. The adhesive free surface is tracked using a pseudo–structural Lagrangian approach. The model is assessed against a well-characterized double-lap HBB joint for which detailed experimental measurements of the adhesive layer thickness were reported in the literature. Comparison between the numerical predictions and the published experimental data demonstrates good qualitative agreement and quantitative consistency throughout the investigated region. For most measurement locations, the discrepancy between the predicted and measured adhesive thickness is comparable to the differences observed between nominally symmetric regions of the experimental distribution. Several simplified assembly models are further investigated, demonstrating that computational cost can be reduced significantly while preserving good agreement with experimental observations. The results confirm the predictive capability of the proposed methodology and support its application to large-scale hybrid joint assembly simulations, particularly in aerospace manufacturing.