The Application Of Non-contact Measuring Method By Laser Vibrometer In Vibration Test

Vibration environment test is very important to ensure the safety and reliability of a newly designproduct during its working time.Generally, the vibration environment test is defined by acceleration; the acceleration response ismeasured by acceleration transducer. The acceleration transducer is mounted on the surface ofspecimen. Because of the limit of the suitable temperature of acceleration transducer (accelerationtransducer could only be used under1000degrees Celsius), so we can’t use it to measure the vibrationresponse of structure in high temperature condition.At present, the non-contact measurement we commonly used is based on laser technology.Generally, the laser vibration measurer could only measure speed or displacement response. So, howto finish the vibration environment test whose reference spectral density is defined by accelerationwith speed or displacement response we get from the laser vibration measurer is important for us.This dissertation introduces how to finish the vibration environment test whose reference spectraldensity is defined by acceleration with speed response. The way how to get acceleration response withspeed response by numerical differentiation is presented. The relationship between the calculatingprecision of numeric differential method and sampling parameters is analyzed emphatically. Atwo-input two-output random vibration environment test is performed with a cantilever beam to verifythe proposed control method, the acceleration signal on one test point is measured by a accelerationsensor and the speed signal on the other test point is measured by a laser vibrometer. A vibrationenvironment test whose reference spectral density is defined by acceleration is finished with bothacceleration response and speed response. Besides, how to translate acceleration test condition intovelocity test condition is discussed in this paper, mainly include: sweep sine, random excitation,classic impact, shock response spectrum and time waveform replication. At last, the theory isexamined by a test using SD...