An overview of the research conducted in the area of linear and nonlinear vibrations in the turning-point frequency range of loudspeakers and revolution shells is given in chapter 1.
第1章回顾了扬声器和旋转薄壳在转点频段的线性和非线性振动，发现旋转薄壳转点问题中尚有若干问题有待进一步研究。
Then the author analyses the effect of the frame vibration and tries to make the natural frequency of vibration beyond the range of engine revolution rate.
分析了发动机振源对车架振动的影响，使车架主要模态的自振频率避开了发动机转速范围；
Then the author analyses the effect of the frame vibration and tries to make the natural frequency of vibration beyond the range of engine revolution rate.
分析了发动机振源对车架振动的影响，使车架主要模态的自振频率避开了发动机转速范围；
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