低温下导弹成像主镜支撑平台微小变形分析

Analysis of the Minor Deformation of Imaging Primary Mirror Supporting Platform of Missile at Low Temperature

某型号导弹导引头在环境试验过程中,其成像主镜在常温时总能够正常抓取目标,但是在低温下却经常出现丢失目标的现象,成像主镜失效的原因是自身面型发生了微小变形。为在后续大批量生产中规避成像主镜在低温下面型变化的问题,有必要对变形产生的原因进行准确定位。以成像主镜低温失效问题为研究对象,建立包含螺钉预紧、低温变形的有限元分析软件ANSYS仿真模型,将产品低温环境试验过程在有限元软件中复现,以此来分析成像主镜失效的具体原因。仿真结果表明:装配工人预紧螺钉对主镜的影响远小于主镜自身受到罩壳螺钉限制而在低温下产生的不均匀变形;成像主镜从装配到低温失效的整个过程,为后续解决成像主镜低温变形问题提供了充足的理论依据,也为后续大批量生产排除了装配方面的顾虑。

During the environmental test of a certain type of missile seeker,its imaging primary mirror can always capture the target normally at room temperature,but it often loses the target at low temperatures.The imaging primary mirror fails because of its own surface shape with small deformation.The cause of primary mirror deformation should be determined to avoid the surface shape of primary mirror changing at low temperature in subsequent mass production.A finite element analysis software ANSYS simulation model,including screw pre-tensioning and low-temperature deformation,was established for the low-temperature failure of the imaging primary mirror,and the process of low-temperature environmental test was reproduced in the finite element software to analyze the specific failure reason of the imaging primary mirror.The simulated results show that the influence of the pre-tightening force of screws on the imaging primary mirror is much smaller than that of the uneven deformation of the primary mirror at low temperature due to the limitation of the cover screws on it.The entire process of the imaging primary mirror from assembly to low-temperature failure is recurred through simulation,which provides a sufficient theoretical basis for solving the problem about the low-temperature deformation of the imaging primary mirror,and eliminates the assembly concerns for subsequent mass production.