Abstract
CFRP (Carbon Fiber Reinforced Plastics) has been widely used to manufacture precise structures, such as antenna reflectors, due to their superior stiffness-to-weight and high dimensional stability as compared to the metallic materials. When one uses CFRP laminates to antenna reflectors for spacecraft, their vibration property becomes important. This is because antenna reflectors are often placed under sever vibration and acoustic noise environment due to the launch of spacecraft. In addition to this, harsh thermal variation becomes also serious problem. Antennas flying on the low Earth orbit are subjected to significant temperature variations, and the thermal deformation of antenna is inevitable. It is possible to suppress this vibration minimally if the laminates are stacked symmetrically. It is known, however, that CFRP laminates show unpredictable deformation caused by the ply angle misalignments during fabrication process. Since the ply angle misalignments are unavoidable so far, it is important to choose the lay-ups mitigating the effect of misalignment. The present paper proposes a multi-objective Taguchi method (MO-TM) to optimize the lay-ups of laminated antenna shell structure to maximize the fundamental frequency and minimize the thermal deformation in robust sense. Both vibration and thermal properties are evaluated by a finite element analysis, ANSYS. The validity of the present optimization is successfully confirmed by the comparison between obtained results from the MO-TM and those from the typical lay-ups.
