Required Section Modulus

Minimum hull-girder section modulus from total bending moment and steel grade allowable stress.

StructuralIACS S11

Still-water BM (magnitude)kN·mWave BM (magnitude)kN·mSteel grade

Allowable stress: 175.0N/mm²

Required section modulus: 19.429m³

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

Z_{min} = \frac{\lvert M_{sw} \rvert + \lvert M_{wv} \rvert}{\sigma_\text{perm}}

Symbol	Meaning	Unit
$\lvert M_{sw} \rvert$ , $\lvert M_{wv} \rvert$	Absolute still-water + wave bending moments	kN·m
$\sigma_\text{perm}$	Allowable bending stress	N/mm²
$Z_{min}$	Minimum required section modulus	m³

Source: IACS UR S11; IACS CSR-H

In short

Minimum hull-girder section modulus from total bending moment and steel grade allowable stress.

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