Lifting beam node#
A LiftingBeam node is a custom node that models a complete lifting beam (aka Spreaderbar) including trunnions and sling protectors.
The properties of the lifting beam are read from a .liftingbeam.csv file. This pre-defines most of the fixed properties such that the used only needs to define the non-standard ones.
Property |
Models |
|
|---|---|---|
Mass / selfweight |
The mass and weight distribution of the beam is pre-defined. The mass of grommet protectors and trunnions is added separately where applicable. |
|
Fixed Trunnions |
Fixed trunnions are pre-defined |
|
Installable Trunnions |
The geometry and possible locations of these trunnions are pre-defined. The user can select if and where they trunnions are installed. |
|
Fixed grommet protectors |
Fixed grommet protectors are pre-defined |
|
Installable Grommet protectors |
Grommet protectors are separate nodes that can be added to the lifting-beam (comparable with how hoists are added to a crane). The geometry of the grommet protector is pre-defined. |
|
Liftpoints |
Fixed liftpoints on a lifting-beam can be pre-defined. |
|
Lifting beam edges |
The edges of a lifting beam need to be modelled explicitly if they need to be able to contact slings or grommets. In that case they are pre-defined and show up as |
Example: “Box beam” : Grommet protectors and beam edges#
The Box Beam is a box-shaped lifting beam. It has rounded-corners and two liftpoints at the ends.
Beams like this can have the tendency to turn upside-down because the downwards force is applied at a higher elevation than the upwards force.
########################################################
# This is an example lifting-beam / spreaderbar
#
# BOX BEAM
#
########################################################
#
# Lines starting with a `#` are comments.
# Lines starting with a `*` indicate the start of a "table"
# A table ends when a new table starts or the file ends or an empty line is encountered.
# Entries are separated by , and/or tabs. Multiple delimiters are ignored treated as one.
# ============== Weight and visual ==================
#
*Visuals
# Name resource off-x, off-y, off-z, rot-x, rot-y, rot-z, scale-x, scale-y, scale-z
MainSteel, res: cube_with_bevel.obj, 0,0,0 ,0,0,0, 5, 0.3, 0.6
*Weights
# Note: interia is not used for statics
# 'Name', 'mass [mT]', 'Cog-x', 'Cog-y', 'Cog-z', 'footprint: elevation', 'footprint: -x', 'footprint: +x', 'footprint: -y', 'footprint: +y', 'inertia: rxx', 'inertia: ryy', 'inertia: rzz'
EQ_main_steel, 20, 0 , 0 , 0 , 0 , -5 , 5 , -0.3 , 0.3 , 1 , 1 , 1
# ============ Liftpoints at ends =================================================================================================================================================================
*Liftpoints
# Name, , x [mm] , y [mm] , z [mm] , diameter [mm], ux , uy , uz,
End A , -5050 , 0 , 0 , 600 , -1 , 0 , 0
End B , 5050 , 0 , 0 , 600 , 1 , 0 , 0
# ! Note: The blank line before this is very important. If it is forgotten then
# then loading the file will error when loading the grommet protectors because
# without the blank-line they are part of the foregoing table.
# ============ Grommet protectors ==========
#
# grommet protector properties
gp_width, 0.6 # [m]
gp_mass, 0.05 # [mT]
gp_radius, 100 # [mm]
gp_elevation, 0.6 # [m]
gp_visual, res: box_beam_protector.obj
# ========== Create a few grommet protectors at fixed places ==========
#
# We can optionally define a table of fixed grommet protectors.
# these are fixed and can not be changed by the user
*GrommetProtectors # data-table defining positions of the fixed grommet protectors
# Name , x [mm]
Protector1 , 3000
Protector2 , -3000
# ========= Corners of the beam ==========
*RoundBars
# Name, x, y, z, radius, x-axis, y-axis, z-axis,draw_start,draw_stop
BottomLeft, 0, 0.2, -0.5, 0.1, 1,0,0, , -5 , 5
BottomRight, 0, -0.2, -0.5, 0.1, 1,0,0, , -5 , 5
Adding new lifting beam types to DAVE#
New lifting beam types can be added to DAVE by placing a .liftingbeam.csv file in one of the DAVE resource paths.
For a the DAVE .csv file format see csv format.
For lifting beams this file contains the following sections:
Beam#
Each beam has a weight properties and visuals. These are typical.
*Visuals
# Name , resource , off-x, off-y, off-z, rot-x, rot-y, rot-z, scale-x, scale-y, scale-z,,,
Visual1, res: cylinder 1x1x1.obj,-6,0,0 ,0,90,0 ,12,1.2,1.2,
*Weights
# Note: interia is not used for statics
# 'Name', 'mass [mT]', 'Cog-x', 'Cog-y', 'Cog-z', 'footprint: elevation', 'footprint: aft', 'footprint: front', 'footprint: sb', 'footprint: ps', 'inertia: rxx', 'inertia: ryy', 'inertia: rzz'
EQ_main_steel, 17, 0 , 0 , 0 , 0 , -6 , 6 , 0 , 0 , 1 , 1 , 1
Visuals needs to be scaled to [m] and rotated such that the origin is at geometric center and lifting-beam is in in x-direction
Liftpoints (optional)#
Fixed liftpoints can be defined on a lifting-beam by providing the following properties:
Name
Location (x,y,z)
Diameter
Direction
*Liftpoints
# Name, , x [mm] , y [mm] , z [mm] , diameter [mm], ux , uy , uz,
End A , -6200 , 0 , -150 , 600 , -1 , 0 , 0
End B , 6200 , 0 , -150 , 600 , 1 , 0 , 0
For trunnions it may be easier to model them as “fixed trunnions” instead.
Frames (optional)#
Optional: Frames: A table of additional frames - For example useful to use as connection points between beams.
*Frames
# Name , x , y , z , rx, ry, rz
Some_name , 1 , 2 , 3 , 70, 0 , 0
Edges (optional)#
For lifting beams where the rigging can contact the edges/corners of the beam, it is advised to add roundbar nodes on the edges of the the beam:
*RoundBars
# Name, x, y, z, radius, x-axis, y-axis, z-axis,draw_start,draw_stop
BottomLeft, 0, 0.2, -0.5, 0.1, 1,0,0, , -5 , 5
BottomRight, 0, -0.2, -0.5, 0.1, 1,0,0, , -5 , 5
Trunnions (optional)#
Fixed and variable trunnions can be defined on a lifting-beam. For both it is required to first define the properties of the trunnion.
Properties of the trunnions#
diameter
width
mass
visual (note 1)
trunnion_dia, 500 # [mm]
trunnion_mass, 1.63 # [metric tonnes]
trunnion_width, 1800 # [mm]
trunnion_visual, res: EQ 180 trunnion.obj # note, needs to be scaled and rotated to [m], origin at geometric center and beam in x-direction
Optionally a cog position can be defined for the trunnions that the user can move.
# Optional settings nonfixed_trunnion_cog, 1.1,2.2,3.3
Optionally an additional liftpoint can be defined to be added to non-fixed trunnions
# Optional setting for additional liftpoint on trunnion trunnion_additional_liftpoint_name, AdditionalLiftpoint, # can be anything trunnion_additional_liftpoint_position, 1, -.1, 2 # position relative to trunnion origin trunnion_additional_liftpoint_diameter, 300 # [mm] trunnion_additional_liftpoint_direction, 0,1,0.5 # direction of axis of liftpoint
Visuals for trunnions#
The visuals for trunnions and grommet protectors can not be scaled, moved or rotated by DAVE. They therefore need to be supplied in the correct scale and orientation. For all DAVE visuals the unit is [m]
For trunnions the Y-axis is perpendicular to the lifting beam and the Z-axis points upwards.
In X and Z direction the origin is located at the center of the trunnion circles. In Y-direction the origin is located at the center.
Fixed trunnions#
Optional: A table of locations where a fixed trunnion is present. This places a standard (as define above) trunnion at that location
Name
Location in x and y direction
*Trunnions # data-table defining positions of the trunnions # Name , x [mm] , z [mm] Trunnion1 , 0 , -1000 Side Trunnion A, 5500 , 0 Side Trunnion B, -5500 , 0
Trunnion slots#
Trunnion slots define slots in which a trunnion can be placed
Name
Location in x and z direction
*Slots # data-table defining positions of the slots # Name , x [mm] , z [mm] Lower 1 , 5250 , -500 Lower 2 , 3650 , -500 Lower 3 , 2050 , -500 Lower 4 , -2050 , -500 Lower 5 , -3650 , -500 Lower 6 , -5250 , -500 Upper 1 , 4450 , 500 Upper 2 , 2850 , 500 Upper 3 , -2850 , 500 Upper 4 , -4450 , 500
Grommet protectors (optional)#
To be able to add grommet protectors (either fixed or movable) to a lifting beam, properties of grommet protectors must be provided in the file:
Width (can be zero)
mass[mT] - the weight is modelled to be at the center of the two circles
radius [mm]
Elevation [m]
Visual
# -- grommet protector properties gp_width, 1.4 # [m] gp_mass, 0 # [mT] gp_radius, 300 # [mm] gp_elevation, 1.4 # [m] gp_visual, res: grommet_protector_eq180.obj # note, needs to be scaled and rotated to [m], see docs for info about origin and orientation
See grommet protector documentation for more details
Fixed grommet protectors#
Optional: A table of locations where a fixed grommet protector is present. This places a standard (as define above) grommet protectors at that location
Name
Location in x
*GrommetProtectors # data-table defining positions of the fixed grommet protectors # Name , x [mm] Protector1 , 0 Protector2 , 5500 Protector3 , -5500
Example file#
# This is an example of a lifting beam
#
# The origin of the liftingbeam is its geometrical center
#
# General settings
trunnion_dia, 500 # [mm]
trunnion_mass, 1.63 # [metric tonnes]
trunnion_width, 1800 # [mm]
trunnion_visual, res: EQ 180 trunnion.obj # note, needs to be scaled and rotated to [m], origin at geometric center and beam in x-direction
# Optional settings
nonfixed_trunnion_cog, 1.1,2.2,3.3
# Optional setting for additional liftpoint on trunnion
trunnion_additional_liftpoint_name, AdditionalLiftpoint, # can be anything
trunnion_additional_liftpoint_position, 1, -.1, 2 # position relative to trunnion origin
trunnion_additional_liftpoint_diameter, 300 # [mm]
trunnion_additional_liftpoint_direction, 0,1,0.5 # direction of axis of liftpoint
#
*Slots # data-table defining positions of the slots
# Name , x [mm] , z [mm]
Lower 1 , 5250 , -500
Lower 2 , -5250 , -500
Upper 1 , 5250 , 500
Upper 2 , -5250 , 500
#
#
*Trunnions # data-table defining positions of the trunnions
# Name , x [mm] , z [mm]
Trunnion1 , 0 , -1000
Side Trunnion A, 5500 , 0
Side Trunnion B, -5500 , 0
#
*Liftpoints
# Name, , x [mm] , y [mm] , z [mm] , diameter [mm], ux , uy , uz,
End A , -6200 , 0 , -150 , 600 , -1 , 0 , 0
End B , 6200 , 0 , -150 , 600 , 1 , 0 , 0
#
*Visuals
# Name , resource , off-x, off-y, off-z, rot-x, rot-y, rot-z, scale-x, scale-y, scale-z,,,
Visual1, res: cylinder 1x1x1.obj,-6,0,0 ,0,90,0 ,1.2,1.2,12,
*Weights
# Note: interia is not used for statics
# 'Name', 'mass [mT]', 'Cog-x', 'Cog-y', 'Cog-z', 'footprint: elevation', 'footprint: aft', 'footprint: front', 'footprint: sb', 'footprint: ps', 'inertia: rxx', 'inertia: ryy', 'inertia: rzz'
EQ_main_steel, 17, 0 , 0 , 0 , 0 , -6 , 6 , 0 , 0 , 1 , 1 , 1
#