振荡激波作用下受热壁板主共振特性分析

Shock wave trains in ramjets often has oscillation characteristics. Studying primary resonance characteristics of heated wall plate under the action of oscillating shock wave plays an important guiding role on structural safety. Here, based on Von-Karman large deformation theory and the local piston flow theory, the dynamic model of a wall plate under oscillating shock wave was established using Galerkin method. Nonlinear dynamic equations were numerically calculated with Runge-Kutta method to obtain the system's nonlinear vibration responses. It was shown that the heated wall plate has typical nonlinear dynamic behaviors, such as, vibration jump and bi-site phenomenon phenomena under the action of oscillating shock wave. Effects of oscillating shock wave intensity, shock wave oscillation amplitude, temperature, shock wave oscillation center position and incoming flow Mach number on the system's vibration jump and bi-stability were analyzed. The results showed that with increase in oscillating shock wave intensity, shock wave oscillation amplitude and incoming flow Mach number, the system resonance peak value increases monotonically, while the bi-site phenomenon interval firstly appears and widens, then narrows until it disappears, and then widens sharply; increase in temperature can produce "stiffness weakening effect" on the system; moving center position of shock wave oscillation to both ends of wall plate can effectively reduce the system resonance peak value and suppress vibration jump and bi-site phenomenon phenomena.