Figure 4

Multi-layer axisymmetric structure with N ₂ = 15 and N ₃ = 30; the angles φ _j,1 = 0 and φ _j,1 = 0.5·Δφ ₀ recur each three layers; P _rd  = 1 year; r ₁  = 1.493837 × 10¹¹ m, m ₁  = 8.889051 × 10²⁹ kg and m _SS  = 3.570164 × 10³³ kg. For the rest designations, see Figure 2.