The Structure Micro-Vibration Response Analysis of Large Scale Precision Mirror Mount

The stability of Laser beams in the high power solid laser facility is the guarantee of target practice successfully, so the laser beams have a strict request to the stability of all kind of optical elements and their mounts structure in the facility. Broadband Ambient Vibration, local vibration, transient temperature change and so on are all the factors that cause the instability of mirror mount. Among these factors, broadband ambient vibration takes a large percentage. Aiming at the problem of a large scale precision mirror mount’s structure stability under the excitation of ambient vibration, this paper discusses the way of ambient vibration measuring by digital seismograph and data process method, gets the velocity spectrum from transforming the ground moving signal collected by digital seismograph, which can be used to the vibration response analysis of precision mirror mount. And then builds the finite element model of the switchyard mirror mount, uses the measured velocity spectrum as the loads, analyzes the response of mirror mount by the spectrum analysis module of ANSYS. The result indicates that the displacement of the choose points on the mirror mount are less than 1.0×10⁻⁶m when under exciting of measured velocity spectrum, which is inside the permitted limit. The analysis indicates that using the result measured by digital seismograph to analyze the mirror mount is reasonable and the ambient can satisfy the requirements of the mirror’s mount.