CALCS PROC050ACCELERATIONS AT POINT DUE TO SHIP MOTIONS

CONTENTS

Guidance: Application, Input, Output & Theory
Notation
Input Data Format
PROJECT EXAMPLE GUIDANCE

Use to determine accelerations at specified points (ex. locations on cranes, process plant, containers, etc) subject to ship motion inertial loading.
Coordinate system is X fwd, Y port & Z up (from LR).
General datum for ship dimensions is Ship Bottom (AB Above Bottom), Aft Perpendicular (AP) and Ship Centre Line (transverse).

APPLICATION

The procedure provides an estimate of accelerations, suitable for the design of structures, at defined points.
See also: BAS005, BAS021. Procedures PROC050 & PROC052 are used in combination.

OUTPUT FROM PROCEDURE

Translational and rotational accelerations at defined points.

THEORETICAL BASIS

See procedure. Motion centres are not precisely defined by closed form solutions because of variable parameters including motion, mass distribution, hull form & draft. The estimate used for the motion centre is the ship centre of gravity. Centrepetal accelerations are not included.

NOTATION

 As Acceleration, at ship CG, suffixes x y z translational (m/s^2), rx ry rotational (rad/s^2) Au acceleration of unit (defined point) (m/s^2) cond operating condition Kg gravity conversion factor (s^2/m) sRx sRy acceleration direction factors (+1 or -1) Ui Unit, point i defined for local accelerations & shown on plot Xcg Ycg Zcg co-ordinates of ship CG (m) Xu Yu Zu coordinates of unit (defined point) (m)

INPUT DATA FORMAT

The following input does not define all the data required to run the procedure. The remainder is input by PROC052.

 TABLE_D_1 T_units Definition of unit locations unit_i unit\$ Xu Yu Zu Kg 1 Point1 31 15 24.7 1/g 2 Point2 57 -7.6 19.7 1/g TABLE_D_0

PROJECT INPUT

 TABLE_D_1 T_Unit Accelerations at locations of units unit_i unit\$ Xu Yu Zu Kg 1 Rmin .3*100.45 22/2+8 9+24 1/g 2 Rmax .3*100.45 22/2+34 9+24 1/g TABLE_D_0

See PROC052