含裂纹圆柱薄壳的动态特性试验研究

AN EXPERIMENTAL INVESTIGATION ON DYNAMIC BEHAVIOR ON THIN CYLINDRICAL SHELLS WITH CRACKS

利用时间平均法分别拍摄了含轴向和环向裂纹圆柱薄壳的激光全息振型图,讨论了裂纹对圆柱薄壳振型及固有频率的影响,把含裂纹壳体的振型分为三个区,即:裂纹周围的局部振动区,壳体原振动区和过渡区.并着重分析了局部振动的特征,得出了局部振动有着自己的独有振形和固有频率的结论,从而很好解释了含裂纹圆柱薄壳的复杂振型图及固有频率的反常变化。

The holographic vibration patterns of thin cylindrical shells with axial cracks or circular cracks are obtained separately with a time-average method and a vibration pattern is divided into three parts: a partial vibration area around the crack, the original vibration area of the thin cylindrical shell and the transition area to analyze the effect of cracks on vibration patterns and natural frequencies of thin cylindrical shells in this paper. The partial vibra-tion is mainly studied, the conclusions obtained are that the partial vibration has its own vibration pat-terns and natural frequencies, so the complex vi-bration patterns and abnormal changes of natural frequencies of thin cylindrical shells with cracks can be explained very well.