1 Reply Latest reply on May 8, 2007 12:03 AM by 1-HHC69

# Parameterizing Parts

I'm attempting to simulate the motion of a cable with a large ball attached to the base. As time passes, I would like the cable to shrink and raise the ball. Is it possible to parametrize the cable so it's length can be changed with an equation in COSMOSMotion?
• ###### Parameterizing Parts
Hello Michelle,

One of the TTMs created this. See if this helps.
Here is a quick sample I puttogether to model a cable using an action reaction force. Itutilizes the underlying algorithm for the impact function, but Iconverted it to be based on a max separation distance instead of aminimum distance.

IF((DM(38,37)-200):0,0,-10000*((DM(38,37)-200)**1.5+STEP(DM(38,37),200,50,200.1,0)*VR(38,37)))

Where:

200 is the length of thecable
DM(38,37) is for the attachmentpoints for the AR force to represent the cable. Hence DM is thedistance between the cable ends
VR(38,38) is the relative velocityof the cable ends
10000 is the stiffness of thecable
50 is the max damping value forthe cable.
1.5 is the exponent for the springstiffness variation (f=k.x^n)
200.1 is the max penetrationdistance at which damping occurs (goes from Cmax at cable length tozero at a length of cable +0.1)

You can build on this to create the operation you were trying todo.

Regards,
Hari