Subcritical divergence experiment method of composite wings in wind tunnel

The divergence experimental prediction and model design techniques were studied for composite forward-swept wings, and the Southwell method, a subcritical divergence experimental technique with testing of structural strain, was used to predict the divergence dynamic pressure. Two high-aspect-ratio composite forward-swept wings were tested using the subcritical method. In order to predict and validate the results of the subcritical experiment, the divergence dynamic pressures were calculated prior to the subcritical wind-tunnel experiment, and the critical divergence wind-tunnel experiments were performed especially after the subcritical wind-tunnel experiment. Both the calculation results and testing results indicate that better results could be attained by using the Southwell method. The subcritical method could be used in high-pressure divergence tests and flight tests. The divergence speed decreases with increase of the forward-swept angle.