Abstract: This article presents numerical simulations of the limit-cycle-oscillation (LCO) behaviors of a cropped delta wing observed in a transonic wind tunnel test by means of a high-fidelity aeroelastic analysis model. In the computational model, the structural part includes the geometric nonlinearity arising from large deflection and the material nonlinearity originated from plasticity, while the aerodynamic part employs the Euler equations to describe the transonic flow. In addition, the interfaces between the structural and aerodynamic domains are built in the form of an exact match where load transfer is performed based on 3D interpolation. The flutter and the LCO of the cropped delta wing are calculated and the results are compared with existing experimental measurements. For lower inflow dynamic pressures, the LCO of the delta wing is caused by structural geometric nonlinearity, and the numerical results correlate well with experimental data. For higher dynamic pressures, the structural material nonlinearity leads to a rapid rise in LCO amplitude, and the varying trend is consistent with experimental observation. The study shows that the LCO of a cropped delta wing is not only closely related to its geometric nonlinearity, but also remarkably affected by its material nonlinearity.

Key words: aeroelasticity, limit-cycle-oscillation, large deflection, plasticity, transonic