The Influence of Stiffened Ribs on Vibration of a Thin-walled Casing

Thin-walled casings with stiffened ribs are widely used in aero engine structures. Reasonable arrangements of positions and forms for ribs can play a significant role in restraining resonance. In this paper, influences of stiffened ribs on the vibration characteristics of the engine inlet casing were studied using finite element (FE) analysis. Experimental studies were carried out to verify the results of the FE analysis. Firstly, by means of FE software, parametric models of the inlet casing with stiffened ribs were created. And then based on the actual working conditions, dynamics of the thin-walled casing with annular stiffened ribs were calculated and discussed. The influence laws of positions of annular ribs, casing wall thickness and cross-sectional dimensions (height and width) of the thin-walled casing structure parameters for the vibration characteristics were studied, which provide empirical data for the design and optimization of engine thin-walled casings with stiffened ribs.