Flutter analysis of bending–torsion coupling of aero-engine compressor blade with assembled clearance

In this paper, the flutter of a compressor blade is investigated to explore the fracture failure mechanism of the blade with an assembled clearance, cubic structural nonlinearity and aerodynamic forces. Firstly, the stability of the linearized system is studied in the neighborhood of an equilibrium point and the threshold speed of the linear flutter of the blade is obtained. Then the response equations of limit cycle oscillations (LCOs) are deduced by using the averaging method, and the stability of LCOs is analyzed based on the first-order approximate theory. Comparisons with the results from the fourth-order Runge–Kutta scheme are carried out, and the accuracy of the first-order approximation of the averaging method is discussed. Finally, the influence of clearance parameter, bending stiffness and torsional rigidity on the flutter characteristics of the blade is analyzed.