Belt Error Message: Belt Segment Length
MADYMO R7.6
Description:
In some situations a MADYMO run may abort with the following message:
** ABORT ** ID=(BLTE01/3D/BNOFO3)
Belt segment /4/2/1 ( /Belts/ Buckle_Belt /Shoulderbelt-Buckle ) :
Distance between attachments is zero at time = 0.0680 s.
100.0 15:04:17 1557.0 63.1 1166.1
This error is generated when there is not enough multibody belt length remaining to allow further belt slip.
Solutions (< R742):
This can be resolved either by
- increasing the multibody belt length, or
- increasing the friction (within realistic values) at the tying point.
Note 1: If the above doesn’t resolve the issue, check whether the contacts are working - for example, by investigating whether
the contact forces on the dummy are realistic.
Note 2: If the abort occurs at the end of the rebound phase and the belt is no longer bearing a load, a workaround is possible.
Define a small ellipsoid at the belt tying point and a stiff contact between this ellipsoid and the FE belt end point(s) at which the
MB belt is connected. Bear in mind the rigid body mass and inertia properties of this small ellipsoid should be small enough
not to influence the simulation.
Solution (from R742 on):
An extra option is available from R742. For mass based BELT_SEGMENTs, the connection between belt segment and FE
belt can be changed to another node of the FE belt if the length of the MB belt segment becomes smaller than minimum belt
segment length (with default value 1 cm). In that case, the MB belts segment is elongated and the extra MB belt segment length
replaces part of the FE belt. Both the MB belt segments and the FE belt must have the same mass per unit length and the same
material characteristics to prevent extra noise during the transition.
In the example below: POINT_REF_1 of the BELT_SEGMENT refers to a POINT_OBJECT.BELT_FE. In this object a
“ordered” list is defined with 3 POINT_OBJECT.MBs.
<POINT_OBJECT.BELT_FE
ID="20"
NAME="BuckleShoulderBelt_pnt"
POINT_OBJECT_LIST="BuckleShoulderBelt1_pnt BuckleShoulderBelt2_pnt BuckleShoulderBelt3_pnt"
MIN_BELT_SEGMENT_LENGTH="0.01"
/>
<POINT_OBJECT.MB
ID="4"
NAME="BuckleShoulderBelt1_pnt"
FE_MODEL="Shoulder_Belt"
NODE="54"
/>
<POINT_OBJECT.MB
ID="22"
NAME="BuckleShoulderBelt2_pnt"
FE_MODEL="Shoulder_Belt"
NODE="53"
/>
<POINT_OBJECT.MB
ID="21"
NAME="BuckleShoulderBelt3_pnt"
NODE="52"
FE_MODEL="Shoulder_Belt"
/>
<BELT
....
<BELT_SEGMENT
1
Questions? Please contact your local MADYMO support office
www.tassinternational.com
Belt Error Message: Belt Segment Length
MADYMO R7.6
ID="1"
NAME="Shoulderbelt-Buckle_bsg"
POINT_REF_1="BuckleShoulderBelt_pnt"
POINT_REF_2="Buckle_pnt"
CHAR="MB_belt_mat_char"
/>
....
</BELT>
In general it is good practice to define the same belt characteristics MB and FE (see frontal _scalded dab application example
e.g.) For this solution it means that the density of the FE belt equals the specific mass of the MB belt segments divided by the
surface area of the FE belt cross-section. It also means that for the MB belt segments and the FE belt the hysteresis model used
must be the same, the material damping switch must be the same and that the hysteresis slope and the loading and unloading
curve used in the characteristic of the MB belt segments must be divided by the surface area of the belt cross-section before
being used in the characteristic of the FE belt.
Note: As of WS R7.5.2 XMadgic beltfitter enables refitting belts modelled with POINT_OBJECT.BELT_FE’s. Prior versions
of Xmadgic can’t handle the new functionality and lists the belt fitter will list: No supported FE belt models detected. A
workaround for those WS versions is to refer to “outer” MB point object MB within the belt segment instead of the Belt FE
point object. Bear in mind to adjust the point object nodes if the belt nodes are adjusted.
2
Questions? Please contact your local MADYMO support office
www.tassinternational.com