| With the development of new hypersonic space rocket,the structure of the rocket will face severe heat,vibration,noise and other complex load environment.In these environments,the thermal stress and thermal deformation of the rocket structure become more prominent,and heat has impact on the stability and dynamic characteristics of the structure which makes the response of the rocket structure more complex.Since the stiffened cylindrical shell structure accounts for about 80% of the whole rocket structure,the rocket structure has been simplified into a stiffened cylindrical shell model for thermal buckling,thermal mode and thermal noise response analysis in this paper.Based on Donnel’s thin shell theory,the buckling equation of stiffened cylindrical shell is established.The critical buckling temperature is obtained by theoretical and simulation calculation.And the reasons for the difference in critical buckling temperature are analyzed.The basic dynamic equation of the stiffened cylindrical shell is established.The vibration frequency of the stiffened cylindrical shell is obtained by using Galerkin principle and perturbation method.And the modal frequency and shape of the stiffened cylindrical shell at different temperatures are simulated and analyzed by Ansys.Under the action of thermal noise,the vibration of the stiffened cylindrical shell crosses the linear and nonlinear stages with the increase of temperature.With Gaussian white noise as the noise load,the real mode superposition method is used to predict the linear random vibration response,and the equivalent linearization method is used to predict the nonlinear random vibration response.The random vibration response of stiffened cylindrical shell with simply supported at different temperatures is simulated,and snap through phenomenon caused by noise excitation after thermal buckling is discussed. |
