Investigation of the dynamic characteristics of a carbon-fiber-reinforced epoxy with adhesive-jointed structure

Structural adhesives are used extensively in the automotive industry, especially in lightweight composite structures where conventional welding is not possible. Nevertheless, in finite element modeling, adhesive modeling introduces errors in the analysis results. In this paper, the authors propose the concept of modeling composite structures assembled with a structural adhesive for structural dynamic analysis. Several models of a double-flanged hat–plate adhesive-bonded joint structure were virtually constructed from carbon-fiber reinforced epoxy, and their performances were compared in a parametric study. All performance criteria were linked to the computational cost, permitting an efficient structural dynamic analysis. To smooth any pre-assembly uncertainties, the individual components were updated by a sensitivity and optimization app (MSC Nastran SOL 200). The dynamic characteristics of the structures were obtained in impact tests under free–free boundary conditions. To assess the accuracies of the FE models of the adhesive-jointed structures, the natural frequencies and mode shapes of each structure were compared with their experimental counterparts. Different types of feasible element connectors for the structural adhesive were also investigated. The proposed ADHSV-based element model was found to represent the structural adhesives both accurately and efficiently.