• Infrared and Laser Engineering
  • Vol. 52, Issue 1, 20220363 (2023)
Jian Yuan and Lei Zhang*
Author Affiliations
  • Chang Guang Satellite Technology Co., LTD, Changchun 130033, China
  • show less
    DOI: 10.3788/IRLA20220363 Cite this Article
    Jian Yuan, Lei Zhang. Structure design and verification of primary mirror assembly for large off-axis TMA camera[J]. Infrared and Laser Engineering, 2023, 52(1): 20220363 Copy Citation Text show less
    Status of primary mirror testing and system alignment
    Fig. 1. Status of primary mirror testing and system alignment
    Diameter-thickness ratio of lightweight mirror
    Fig. 2. Diameter-thickness ratio of lightweight mirror
    Parameters of lightweight structure in primary mirror
    Fig. 3. Parameters of lightweight structure in primary mirror
    Main contents of integrated analysis model
    Fig. 4. Main contents of integrated analysis model
    Solution process of two objective optimization problem
    Fig. 5. Solution process of two objective optimization problem
    Supporting structure of primary mirror
    Fig. 6. Supporting structure of primary mirror
    Structure of flexure
    Fig. 7. Structure of flexure
    Relationship between flexure structure slot position and mirror deformation
    Fig. 8. Relationship between flexure structure slot position and mirror deformation
    Finite element model of primary mirror assembly
    Fig. 9. Finite element model of primary mirror assembly
    Thermal deformation nephogram of primary mirror
    Fig. 10. Thermal deformation nephogram of primary mirror
    First order vibration mode of primary mirror assembly
    Fig. 11. First order vibration mode of primary mirror assembly
    Auxiliary bonding device for primary mirror assembly
    Fig. 12. Auxiliary bonding device for primary mirror assembly
    Flow chart of stress relieving for primary mirror assembly
    Fig. 13. Flow chart of stress relieving for primary mirror assembly
    Layout of optical accuracy test for primary mirror
    Fig. 14. Layout of optical accuracy test for primary mirror
    Interferogram of primary mirror during optical accuracy test
    Fig. 15. Interferogram of primary mirror during optical accuracy test
    Sweep test results of primary mirror assembly
    Fig. 16. Sweep test results of primary mirror assembly
    ItemRequirement
    Clear aperture1250 mm×460 mm
    Mass≤80 kg
    Tiltθ≤10″
    Displacementδ≤20 μm
    Surface accuracyRMS≤1/50λ (any φ400 mm area)
    Working temperature(20±2) ℃
    Frequency≥110 Hz
    Table 1. Design requirements for primary mirror assembly
    PropertyRB-SiCBeULEZerodur
    Density, ρ/kg·m−33050185022102530
    Elastic modulus, E/GPa 3402876791
    Poisson ratio, μ0.20.080.170.24
    Thermal conductivity, λ/W·K−1·m−11552161.311.64
    Thermal expansion coefficient, α/10−6·K−12.5011.40.030.05
    Specific stiffness, E/ρ111.515530.336
    Thermal stability, λ/α6218.943.732.8
    Comprehensive performance, (E/ρ)·(λ/α) 6913293913241180
    Table 2. Properties of common materials for large mirror
    ParameterLimitsOriginalOptimizedAdjusted
    Face, F[5,10] 65.635
    Back, B[3,8] 64.374
    Perimeter, P[3,8] 53.274
    Cone, C[8,14] 1514.3212
    Central rib, R1[3,8] 53.284
    Exposed rib, R2[3,8] 53.103
    Side trimming, H1-100-116
    Central trimming, H2-50-38
    Table 3. Variable ranges and optimization results (Unit: mm)
    PartConeFlexureBase
    Material4J36TC4SiC/Al
    Density, ρ/kg·m−38.14.43.0
    Elastic modulus, E/GPa 141114180
    Poisson ratio, μ0.250.340.18
    Thermal expansion coefficient, α/10−6K−12.59.18.0
    Table 4. Material properties of supporting structure
    Temperature change, 4 ℃ Gravity, 1 g, -YUnflatness, 0.01 mm
    RMS/nm 3.9832.0350.295
    θX/(″) -1.217-
    δY/μm -9.541-
    Table 5. Simulation results under main conditions
    OrderFrequency/HzVibration mode description
    1126.7Mirror rotation around Y axis
    2146.6Mirror rotation around X axis
    3160.1Mirror rotation around Z axis
    Table 6. Modal analysis results of primary mirror assembly
    Jian Yuan, Lei Zhang. Structure design and verification of primary mirror assembly for large off-axis TMA camera[J]. Infrared and Laser Engineering, 2023, 52(1): 20220363
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