复合材料机匣的弹性稳定性及振动特性研究

Elastic stability and vibration characteristics of a composite case

采用Flügge壳体理论,分析了径向内压对复合材料机匣的弹性稳定性(屈曲特性)的影响,并讨论了几何参数及材料特性对屈曲特性的影响。研究分析表明,在强度允许的范围内,径向内压的提高有助于提高机匣的抗屈曲能力。进一步应用振型叠加方法,研究了复合材料机匣在径向内压作用下受到径向简谐激励作用时稳态动力响应问题,在特定径向简谐激励的作用下,径向位移响应的最大值在激励面和非激励面对应的频率点不同,激励面内出现在第三阶频率点处,而在非激励面内则出现在基频处。

Influences of radial internal pressure on elastic stability（ buckling characteristics） of a composite case were analyzed based on the Flügge shell theory,in addition,influences of its geometric parameters and material properties on its buckling characteristics were also discussed. Results showed that increasing the internal pressure can improve the anti-buckling ability of the case within the limits of its strength. Furthermore,the dynamic responses of the composite case under a radical harmonic force were studied by applying the mode superposition method. It was shown that under the radial harmonic excitation,the frequencies of the maximum radial displacements in the excitation force plane and in the non-excitation forced plane are different; more specifically,the maximum radial displacement in the excitation force plane appears at the 3rd modal frequency of the case,but that in the non-excitation force plane appears at the fundamental modal frequency of the case.