复合材料格栅反射器结构热变形及精度分析

Thermal deformation and accuracy analysis of composite grid reflector structure

摘要:

为满足卫星通信领域反射器高精度和轻量化的要求,以某地球同步轨道气象卫星反射器为应用背景,采用ABAQUS有限元模拟复合材料反射器的热变形并运用最小二乘拟合原理计算其型面精度RMS值,利用M55碳纤维复合材料层合板面内热膨胀系数较小的特性设计出全复合材料格栅反射器结构.在相同工况的条件下,采用工业近景三维测量方法对格栅反射器结构进行热变形实验测试,利用工作面变形的均方根RMS值来表征型面精度,并将测试值与模拟值进行比对发现两者吻合较好.最后对格栅结构反射器的装配误差,粘接方式,胶层厚度,蒙皮和筋条的铺层角度等影响型面精度RMS值的因素进行计算分析,结果表明:粘接方式和胶层厚度是影响全复合材料格栅反射器型面精度的最主要因素,并且蒙皮与格栅结构的胶接更宜采用点粘方式,同时随着胶层厚度和装配误差的增大,型面精度呈现非线性的增长趋势.在相同工况、相同宏观结构尺寸的前提下,与碳纤维铝蜂窝夹层结构反射器结构相比,全复合材料格栅结构反射器的型面精度仅为0.455 μm,型面精度提高了一个数量级,为高精度深空探测和信号传输提供了可靠设计方案.

Abstract:

In order to meet the requirements of high precision and light weight of reflectors in the field of satellite communications, the ABAQUS finite element was used to simulate the thermal deformation of the composite reflector and the RMS value of the profile accuracy was calculated by the least squares against the background of a geosynchronous orbit meteorological satellite reflector. The full composite grid reflector structure was designed by using the in-plane thermal expansion coefficient of the M55 carbon fiber composite laminate. Under the same working conditions, the industrial three-dimensional measurement method was used to test the thermal deformation of the grid reflector structure and the root mean square RMS value of the deformation of the working face was used to characterize the profile accuracy. It shows that the test value was approximately equal to the simulated value. Finally, factors affecting the RMS value of the profile accuracy were analyzed, such as assembly error, bonding method, thickness of glue layer, layup angle of skin and ribs. Results show that the bonding method and the thickness of the glue layer were the most important factors affecting the profile accuracy of the full composite grid reflector, and point bonding was more suitable for the bonding of the skin and the grid structure. At the same time, with the increase of the thickness of the glue layer and the assembly error, the profile accuracy showed a nonlinear growth trend. Compared with the carbon fiber aluminum honeycomb sandwich structure reflector, the profile accuracy of the full composite grid structure reflector was only 0.455 μm under the same working conditions and the same macroscopic structure size, which was increased by an order of magnitude. It provides a reliable design for high precision deep space exploration and signal transmission.