Analysis And Verification Of Composite Plates Sea Model

In the early development of hypersonic aircrafts, SEA is an effective way toanalyze the mid-high frequency response of aircrafts. In this article, the way to modelhoneycomb sandwich panels and heat-resistant metal-composite composite platestructures which are commonly used in hypersonic aircrafts, are researched by SEA.The article first derives the modal density formula of uniform panels, and obtainsthe general method of modal density calculation for plate structures, that is firstmodeling the equations of dynamic behaviors, and then applying wave solutions todynamic variables to obtain the characteristic equation of frequency and wave number(wave number curve), with which we can achieve the modal number and modal densityby calculating the area under the wave curve in the wave space. The article then derivesthe modal density formula for both sandwich composite panels and metal-compositecomposite plate structures. In the low frequency the composite plates are modeled bythin-plate theory and the composite plates are modeled by thick-plate theory in the highfrequency. When the frequency increases up to special value, the sandwich compositeplates behave differently, and are modeled by thin-plate theory, but the dynamic modelis different from low-frequency model, only half of the sandwich composite panel ismodeled. And the article last verifies the modal density formula of composite platesSEA models by numerical examples.At the same time, this article uses sandwich plate theory to model aluminumhoneycomb plate, and analyzes the response of honeycomb plate by SEA. Bycomparing the response with the random vibration test results, the SEA model ofhoneycomb plate is verified to be reasonable and accurate.