HomeCalculatorsCollision Energy Absorption (DNV)

Collision Energy Absorption (DNV)

Bow-to-side collision kinetic energy at impact: E = ½ · M_eff · V² between two ships of different size.

StructuralCollision
Effective mass (reduced + added)
31,590t
Collision energy
0.3MJ

Formula, assumptions, and limits

$$E = \tfrac{1}{2} M_\text{eff} V_\text{rel}^2, \quad M_\text{eff} = \frac{M_1^* \cdot M_2^*}{M_1^* + M_2^*}$$

M* = displacement × (1 + added-mass factor). Striking ship added mass ≈ 0.10 (bow motion); struck ship ≈ 0.40 (sway + yaw). Side-shell absorption depends on structural grillage and bulb shape. DNV-RP-C204 method.

Symbol legend

SymbolMeaningUnitSource
$M_1^*, M_2^*$Effective (added) massestdisplacement + added mass
$V_\text{rel}$Relative speed at impactm/soperating condition

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