| Aircraft is subjected to fluctuating pressure as it flying at a high speed. For the structure ofaircraft, the so called fluctuating pressure is a random excitation distributing on the out surface ofaircraft, which may induce violent random vibration of structure and even result in destroy ofstructure. In order to enhance the aircrafts’ structural stability and reliability, this paper is devoted tothe response of aircraft structure subjected to fluctuating pressure, and related structure fracturephenomena. The main contents of this paper are listed as fellow:At first, the engineering estimation formulae of different basic fluctuating pressure environmentare summarized in this paper. The influence of the spatial correlation of fluctuating pressure to theresponse of simply supported beam is analyzed theoretically. And the finite element meshing criteriais obtained according to wave theories as the spatial correlation of fluctuating pressure is taken intoaccount.Then, taking an aircraft with cone cylinder structure as an example, some statistical parametersfor fluctuating pressure imposed on the outside surface of the aircraft were obtained by usingengineering estimation formulae. The mean square response of aircraft structure subjected to thefluctuating pressure is calculated while the spatial correlation of fluctuating pressure was taken intoconsideration. In order to study the effect of the spatial correlation of fluctuating pressure on theresponse of the aircraft structure, the results under two traditional calculation methods where thespatial correlation is neglected were obtained and compared with the result of the method motionedabove.Finally, the extension angle of crack was calculated by extended finite element method (XFEM),while a simply supported beam subjected to random excitations, and initial cracks were assumed toappear in different positions of the beam. And the whole crack propagation process was simulated byXFEM also. |
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