Research and application of improved thin-layer element method of aero-engine bolted joints

A new dynamic modeling method called the improved thin-layer element method is proposed to apply to the aero-engine bolted joints. The thin-layer elements are partitioned based on the interface contact stress distribution. In addition, the material parameters of the partitioned thin-layer elements are determined by the bolted joints stiffness technique and the fractal contact theory without the experimental results, which allows the engineer to estimate the dynamic characteristics of whole structure before the physical prototype is available. First, the modeling principles of the improved thin-layer element method are studied and the bolted joints stiffness is analyzed. Next, the material parameters of the partitioned thin-layer elements are determined on the basis of the interface contact stress distribution characteristics of the bolted joints. Finally, this method is applied to the simulative casing bolted joints structure and the results are compared with the experimental results in order to verify the proposed method. The results indicate that the improved thin-layer element method is more accurate than the thin-layer elements method, and the material parameters of the partitioned thin-layer elements can be expressed by the structural parameters of the aero-engine bolted joints without updating based on the experiment.