Since the hypersonic vehicle is acted by a serious aerodynamic thermal load caused by the flight through the atmosphere, it is necessary to consider the effect of the high temperature in the ground test of the vehicle structures. But the structural modal experiment in a high temperature environment is far more complex than the normal modal experiment with many technical difficulties to be solved. In this paper, the advance of the thermal modal test technology is reviewed. The characteristics and the applicability of the excitation and measurement techniques to be used in the high temperature environment are discussed in detail. The development direction and the research focus of the structural modal test technology in the high temperature environment are suggested.
Based on commonly used experimental methods in fracture mechanics, with special consideration of the features of the interface fracture, an experimental method for the interface crack is established in the framework of fracture mechanics. With this method, the critical energy release rate can be obtained through the measurement of the load and the displacement of the specimens, for a given length of a crack. Related experiment data verify the robustness of this method, and the qualified consistency between the set of experimental results and the corresponding ones obtained by this method. Further, with this method, the maximum load capacity of the structure can be predicted according to the impedance energy curve. So, this analytic method is a powerful experimental method for the determination of the strength of the interface crack through the energy release rate with wider applications.