A31 E

where the product V0A31 is positive.

The configuration is displayed by Fig. 3.12-Right, and dimensionless distribution Tsi(p) by Fig. 3.12.

The central part of the mirror can be considered as infinitely rigid, so that the only reaction to the prismatic ring-force Vr{a} can be generated by a central moment My around the y-axis determined by n/2 2

For practical reasons, the reacting moment can be applied at a small distance from the mirror center where b C a.

The radial and tangential maximum stress or and ot must be lower than the ultimate stress cult of the material. Substituting the Coma 3 flexure mode in (3.1a), we obtain the radial bending moment

The radial maximum stress or = 6Mr/t2, derived with the scaling thickness t0 in (3.45b) and the definition of the rigidity, is

lo where Sr is a dimensionless maximum stress (Fig. 3.13)

Fig. 3.13 VTD class: Coma3 flexure mode Z31 = A3ir3cos6. Dimensionless thickness T31 = [ 3+v ( P-2 — 1) ]1/3 with p = r/a. Dimensionless maximum stress Sr = p T31 cos O plotted for O = 0
0 0

Post a comment