Towards the effect of cracks on the instability of a plate loaded by low-speed axial flow

• Published in: Thin-walled structures 2024-05, Vol.198, p.111685, Article 111685
• Main Authors: Cui, Junzhe, Li, Peng, Yin, Hong, Zhang, Dechun, Yang, Yiren
• Format: Article
• Language: English
• Subjects: Aeroelasticity; Axial flow; Cracks; Instability; Plate
• ISSN: 0263-8231; 1879-3223
• DOI: 10.1016/j.tws.2024.111685

This paper presents a model of a cantilevered plate with arbitrary cracks in an axial airflow and the crack’s effect on the plate’s aeroelastic instability. It employs the Dirac function to delineate the effect of cracks on the plate’s bending stiffness and utilizes Fourier series coupled with a mirroring technique to calculate the slope function of the cracked plate. The Theodorsen aerodynamic theory gives the fluid pressure, and the Galerkin method applies to the discretization of the fluid–structure interaction equation. The investigation encompasses three scenarios: single, double, and multiple arbitrary cracks. The flutter boundary of the structure is calculated and analyzed under different parameters. The modal participation factor is used to explore the effect of each structure mode on the plate instability. The results show that cracks significantly affect the plate’s stability. The existence of cracks not only affects the critical flow velocity but also affects the characteristics of the instability mode. When the number of cracks is small, some special positions of the cracks will trigger the structure’s higher-order modes and increase the critical speed. When the number of cracks is large, and the distribution of cracks is uniform, the structural stiffness decreases and critical speed. •A series of expansions and a mirror process of plate configuration were applied to overcome discontinuity by cracks.•The combined effect of mass ratio and crack location leads to a rise in the instability boundary.•Besides a change in the critical velocity, the significant effect of crack location on the instability modes.•Cracks can excite the plate’ higher-order modes, leading to an increase in critical speed.