The quasi-similarity method is applied to the inviscid steady hypersonic source flow past slender bodies. Next, the results are corrected by taking into account the displacement effect of the boundary layer along the body surface, using the local similarity method. The corrected distributions of the pressure along slender powerlaw bodies of revolution are calculated, which give essentially good agreements with experimental results.
A wind tunnel test was performed for active flutter suppression of a two-dimensional wing model by controlling the rotation of aileron in the use of D.C. servomotor as an actuator. The location of center of gravity, the frequency ratio and the mass ratio of the test model were at 40% chord length, 0.36 and 64, respectively. The experimental results showed that about 37% increase in flutter speed by feedback of the rotation angle and about 57% increase by feedback of the rotation angle and the translation were achieved. Furthermore, in the case of combined feedback of the rotation, its velocity and the translation no flutter was encountered even at 30m/s, i.e. the maximum speed of the wind tunnel that was two times of the open loop flutter speed. The test results were in good agreements with theoretical values which were calculated by taking the response characteristics of the actuator system and the reaction of actuator torque to the model into consideration.
The buckling strengths of three kinds of CFRP laminated panels (0°, ±45°, 0°+90°) and one epoxy panel with all edges clamped under uniaxial compression are investigated. From the experimental results, it can be observed that the failures of panels occur in the state of the secondary buckling mode after snap-through phenomena except a 0° panel. Nonlinear buckling analysis is based on the incremental assumed displacement compatible model, and three types of failure theories are employed for predictions of fracture strengths. The results thus obtained agree well with those by the experiments. It can be concluded that the 0°+90° panel has the highest fracture strength among test specimens. Furthermore, the optimum design with maximum primary buckling load and the effective width after buckling are theoretically studied for simply-supported laminated panels. The results show that the in-plane boundary conditions at loaded edges have important effects and that the snap-through phenomena may be possible.