Home > List of Keywords > *WINCHTEN
*WINCHTEN
Data format:
One line comprising 11 values
NWIN T0 DTMIN DTMAX TRAMP NODE NGR NEL NEL LMAX LMIN IFLAG
Purpose :
To define a tension controlled winch
Restriction :
Only available for dynamic analysis
Details :
| Parameter | Description |
|---|---|
| NWIN | winch number previously defined with *WINCH; If NWIN=0, NODE, NGR, NEL must be provided |
| T0 | reference tension |
| DTMIN | tension range (min) |
| DTMAX | tension range (max) |
| TRAMP | ramptime for winch |
| NODE | Reference node for the tension |
| NGR | Winch group (only if NWIN=0) |
| NEL | Reference Element for the tension (only if Nwin=0) |
| LMIN | length unchanged if LMIN reached (LMIN>0 otherwise inactive) |
| LMAX | length unchanged if LMAX reached (LMAX>0 otherwise inactive) |
| IFLAG | = 0 unchanged =1: length unchanged if tension is between TO |
Note
The reaction force at node NODE is computed and projected onto the local axis of the element (NWIN for winch defined as a spring, NEL for a winch defined as a group of elements). If more than one line is linked to the node, the total reaction force is taken into account. Since the reaction force is used, at least one of the translation d.o.f. of NODE must be constraint or clamped.
A winch with constant velocity must have been previously defined. The winch is unwound if Tension>T0+DTMAX, wound if Tension<T0+DTMIN and unchanged otherwise. The maximum velocity is given by the constant velocity of the winch. The maximum absolute acceleration of the winch is given by the constant velocity divided by the winch ramptime TRAMP.
If TRAMP is not at least twice the maximum time step, TRAMP is adjusted.
The keyword is only useful in dynamic. A file winchiii.dat is created with 4 columns containing time, velocity, tension and length.
