Modeling the elastic-plastic behavior of a rotor support structure under a large unbalance: numerical simulations

In this paper, we seek to model the elastic and plastic behavior of a rotor engine under extreme radial load conditions, such as when blade loss occurs. In particular, we focus on the resistance to plastic collapse of the rotor bearing support structure when a large radial force is acting in a circular orbit on the inside of the bearing housing. In our numerical model, we have used a new type of element, labeled Enhanced Assumed Strain (EAS), which presents an improved flexural behavior. This element allows us to keep the advantages of volume elements, while reproducing the good behavior of shells in bending. In a first stage, we have considered simple, hat-shaped geometries, with two different materials: mild steel, and titanium. In a second stage, a numerical model of a real front bearing support structure (FBSS) was studied. Comparison with experimental results from CERES contributed to the validation of the proposed modeling approach.