# Stiffening rings for cylindrical for the the combined ringshell

## Values for calculation

$T$ $\mathrm{°C}$
$P$ $\mathrm{MPa}$
$D_o$ $\mathrm{mm}$
$L_s$ $\mathrm{mm}$
$t$ $\mathrm{mm}$
$A_s$ $\mathrm{mm^2}$
$I^´$ $\mathrm{mm^4}$
$A$

## Calculation

### Factor $B$

$$B=\cfrac{3}{4}\cdot\left(\cfrac{P\cdot D_o}{t+A_s/L_s}\right)$$

### Required moment of inertia of the combined ringshell cross section about its neutral axis parallel to the axis of the shell

$$I^´_s=\left[D_o^2\cdot L_s\cdot\left(t+A_s/L_s\right)\cdot A\right]/10.9$$$$I^´_s\le I^´$$