大口径光栅拼接架动力响应控制分析

Dynamic Response Control and Analysis of Large Aperture Tiled Grating Mount

光栅拼接是解决光栅口径限制的有效途径,而结构稳定性成为光栅拼接研究中面临的主要难题。目前使用的光栅拼接架稳定性不能完全满足实验需要,为明确影响光栅拼接稳定性的主要因素,采用多通道振动测试仪对环境振动进行了测试,结果表明供热通风与空气调节(HVAC)振动是影响光栅拼接架稳定性的主要因素;采用实测功率谱作为激励,对光栅拼接架进行了优化分析,分析结果表明增加结构阻尼比可以降低拼接架动态响应;根据有限元分析结果,采用高阻尼材料对拼接架运动结合面的连接状态进行了改进,实验表明改进后的光栅拼接架动态响应大幅减小,同时稳定时间得到延长。

Tiled grating is an important approach to solve the problem of grating aperture limit,however,which will meet the problem of structral stability of tiled grating.According to the requirement of operation,the tiled grating mount was used,but the stability of tiled grating mount cannot satisfy the requirement fully.In order to determine the main factors which affect the stability of the grating mount,a muti-channel vibration test equipment is used to measure the ambient vibration around grating.The test indicates that vibration of heating,ventilation and air conditioning（HVAC） are the main factors that affect the stability of grating mount.The power spectral density of test（PSD） is used to optimize the dynamic response of the grating mount and the results indicate that increase of structure damp ratio can decrease the dynamic response of grating mount.According to the finite element analysis,the joint damp of grating amount′s combination planes is increased by applying high damp material.The experiment indicates that increase of structure damp ratio not only reduces the dynamic response greatly but also prolongs the stability time.