Accurate test of natural frequency of constrained thin cylindrical shell

作者：Li Hui^*; Sun Wei; Zhang Yong Feng; Han Qing Kai

来源：Journal of Northeastern University, 2013, 34(9): 1314-1318.

• Base excitation
• Constraint boundaries
• Constraint state
• Excitation signals
• Experimental system
• Inherent characteristics
• Laser Doppler vibrometers
• Thin cylindrical shell

For better understanding its vibration behavior, inherent characteristics of constrained thin cylindrical shell were calculated by transfer matrix method and FE method, respectively. Factors affecting high-precision test of natural frequency and their solutions were analyzed. The methods of using the torque wrench to quantitatively determine the constraint boundary conditions and adopting reasonable excitation signal, additional window and average processing were chosen to improve the test accuracy. Furthermore, four types of excitation experimental systems including hammer, electromagnetic exciter, piezoelectric ceramic exciter and vibration shaker were set up to measure natural frequencies and key test steps were exhibited. The results show that base excitation produced by vibration shaker does not bring any additional mass and stiffness to thin cylindrical shell and is in good accord with its real stress-constraint state. Thus, the combination of vibration shaker for excitation source and laser Doppler vibrometer for response test has the highest test accuracy of natural frequencies.

• 出版日期2013
• 单位东北大学