How to eliminate the error #721

MOHAMMAD UMAR MAKNOJIYA

I was going through linear transient heat transfer analysis of the piston,and I have created all the load collectors for temperature on the piston, ambient temperature, time step, etc.
But when moved to the Optistruct solver to determine the results, I found this error appearing in the message log of the solver..

"Messages for the job:

*** ERROR # 721 ***
An SPCD component must be constrained by an SPC or SPC1 data.
There are too many of such unconstrained SPCD in the model.
Please correct the input and rerun the problem."

It would be a great help if anyone helps me out to resolve this error!

Viraj_Kulkarni

If you apply SPCD you need a SPC constrained in all directions. Applying SPCD is an old way of doing things, its still used. However you need to make sure you create SPC at same node as well.

 

Another way of doing things is to not use SPCD and just use SPC directly, so you dont have to do double efforts.

But to organize its better to have actual constrained SPC in one load collector, SPC used as enforced disp/temp in another load collector. Then use SPCADD load collector to combine them. Then you refer the SPCADD load collector as an SPC without load in the loadstep.

Difference in SPCD approach is SPCD are referred as load in loadstep and you need to create SPC as well.

Both ways work.