Cargo Support Reaction Force Calculator

Rigid-body-on-elastic-supports (6x6 stiffness matrix). Axis convention: X=longitudinal (+fwd), Y=transverse (+stbd), Z=vertical (+down, supports below CoG have positive Z). Fz>0=compression, Fz<0=uplift.

1. Cargo Data

Project / description (optional) Mass, W (tonnes) g (m/s^2)

2. Supports

Enter X/Y/Z relative to the cargo CoG and the 4 stiffness values (grillage, lashing/dogplate, and the two horizontal stopper/brace directions). No fixed row limit -- add exactly as many as you need.

	ID	X (m)	Y (m)	Z (m)	Kz-down (kN/m)	Kz-up (kN/m)	Kx (kN/m)	Ky (kN/m)

Paste from Excel: copy a range with columns in order ID, X, Y, Z, Kz-down, Kz-up, Kx, Ky (no header row -- a 7-column paste without ID also works, IDs auto-generate), then paste below.

3. Ship Motion

Max Roll angle (deg) Max Pitch angle (deg) Max Heave accel (m/s^2, +down) Max Sway accel (m/s^2, +stbd) Max Surge accel (m/s^2, +fwd)

ax, ay, az must already be the TOTAL translational acceleration at the cargo CoG (i.e. already including any rotational/offset contribution). Roll/pitch angle is used only to resolve the gravity component.

Wind Load (optional)

Wind Fx (kN, longitudinal) Wind Fy (kN, transverse)

Enter wind force already calculated separately, in kN (not speed/pressure). Applied at the CoG and swept +/- for a conservative envelope, same as the other components. Leave at 0 if not applicable.