How to enforce a gradual elongation

Yuri S.

Hi,

I would like to apply a gradual displacement to a node. In particular, I would like to define the displacement as a function of time.
Could someone tell me how I should set up the analysis or point out a tutorial pertinent to my need?

Thank you!
Yuri

Adriano Koga_20259

Assuming that you're using OptiStruct, you can run a NLSTAT analysis.

NL quasi-static assumes a gradual load increment for your loadings or enforced displacement, from 0 to 100% of your value.

So if you're using a SPCD as enforced displacement, it will go from zero to 100% of your displacement.

 

Now if you want a specific displacement over time, you can use a dynamic load, such as loadcollector TLOAD1 (if i'm not wrong, to be used as DLOAD in your loadstep).

In this case, you can specify a TABLED1 curve that defines your time varying load/displacent, combined with your SPCD.

TLOAD1 essentially defines a F(t) = SPCDvalue * your_table_over_time

Adriano Koga_20259

Assuming that you're using OptiStruct, you can run a NLSTAT analysis.

NL quasi-static assumes a gradual load increment for your loadings or enforced displacement, from 0 to 100% of your value.

So if you're using a SPCD as enforced displacement, it will go from zero to 100% of your displacement.

 

Now if you want a specific displacement over time, you can use a dynamic load, such as loadcollector TLOAD1 (if i'm not wrong, to be used as DLOAD in your loadstep).

In this case, you can specify a TABLED1 curve that defines your time varying load/displacent, combined with your SPCD.

TLOAD1 essentially defines a F(t) = SPCDvalue * your_table_over_time

Yuri S.

Thank you for the kind reply.
The procedure suggested is succesful.

The only remaining dubt regards the displacement entity: I am trying to stretch a 1x1x1 cube in the x direction by enforcing a displacement as a DOF1=3. Nevertheless, in the results I keep finding a displacement equal to 6.

Do you have any suggestion about this too?

Thank you.

I attach the model.