rotacional spring

chen · Post by **chen** » Wed Apr 27, 2005 9:45 am

Hi
When I am definig a rotacional spring. How does it work?

zero length element
Have I to calculate by my self the value of stiffness and introduce it ,or I just give the value of modulus elasticity givind the material

zero length element section
Wiht parameter OP takes of the section and How OP obtains the stiffness of the spring

thanks

silvia · Post by **silvia** » Wed Apr 27, 2005 11:11 am

you assign a material tag or section tag associated with the element.

chen · Post by **chen** » Wed Apr 27, 2005 11:14 pm

Hi, silvia I Knew but
I want to simulate a elbow.
My data are of course the materials parameters and the stiffness in z axis, that's means moment-rotation relation.
But I don't Know how enter it.

when I assign a material tag does E mean the stiffness of the elbow?

when I assign a section tag what parameter of the section represents this stiffness?
Thanks

berktaftali · Post by **berktaftali** » Thu Apr 28, 2005 2:58 am

If you are going to use the material with a rotational spring, then yes, you should enter the rotational stiffness for E of the material.

Don't let the "material" in uniaxialMaterial confuse you. It defines a generic force-deformation relationship. You tell what it is going to represent (stress-strain, moment-rotation, moment-curvature, etc.) when you assign it to a section or an element...

Hope this helps...