Highlighted

Spring with pre load

Creator
Creator

It's possible to add a pre load in a spring element (like Celas2)?

6 REPLIES 6

Re: Spring with pre load

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

The CELAS2 spring element do not support preload with NX NASTRAN BASIC Nonlinear Analysis (SOL106).

CELAS2-spring-element.png

But you always can preload a CROD element using an equivalent thermal load approach, or with NX NASTRAN ADVANCED NONLINEAR solver (SOL601) you can use a CBAR/CBEAM element that support directly BOLT PRELOAD.

Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Spring with pre load

Creator
Creator

Thanks for your answer.

Adding a bolt pre-load seems not to be what I'am looking for.

I want to join these two surfaces together and calculate the deformation.

I thought to add spings with 0 mm free length on the edges

Re: Spring with pre load

Siemens Phenom Siemens Phenom
Siemens Phenom

Preload can be defined on a CGAP element by specifying F0 on the PGAP card.

Re: Spring with pre load

Creator
Creator

Hi Jim,

I tried it out in NX12, but it didn't work. And I have the same Problem to define a preloaded spring. Is there any other possibility to create it?

 

regards Andreas

Re: Spring with pre load

Genius
Genius

It is not clear if you want a preloading force acting on the spring, or if you want to compress the spring with an enforced displacement elongation.

Maybe you can use three different strategy:

  1. Add manually the load to your spring and adjust it iterativelly according to the displacement measured in the previous simulation;
  2. Add manually an enforced displacement and adjust it iterativelly;
  3. Use a beam and load it with a thermal expansion and adding a thermal load;
  4. If you want to get a precise preloading force you can also use a "bolt preload" in order to obtain a specified level of force (the same of #1, but performed automatically by the solver and not iterativelly by you)

In general I suggest to use a low-stiffness spring in order to get a small variation of load if the structure moves a little bit.

Re: Spring with pre load

Creator
Creator
Thanks a lot, I will try out to combine the bolt preload with a spring