Abstract: Modal analysis is of great significance for product design optimization, engineering structure stability, damage detection, etc., and vibration testing technology is the basis of modal analysis. For the contact measurement test based on piezoelectric sensors, contact sensors, such as acceleration sensors, must be installed on the workpiece surface. Therefore, the non-contact testing technology represented by laser Doppler vibration measurement technology can avoid the influence of additional mass and has advantages for such testing. In order to understand the performance of different test tools and means in the actual engineering environment, so as to obtain higher precision measurement data. The accuracy comparison between piezoelectric sensor and Doppler laser vibrometer in modal testing is carried out. It is concluded that the modal accuracy of piezoelectric sensor and laser vibrometer is the same in low-order mode, while in high-order mode, laser vibrometer has advantages in measurement accuracy, no additional mass effect and vibration mode performance.

Key words: Modal analysis, Simulation accuracy, Laser vibration measurement