Springs with variable stiffness property

Javid Moraveji

1) Is there an element type/property available that can represent a nonlinear spring with a variable stiffness as a table?   

2) Is there a way to specify the force at the tip of a spring (linear CBush1D or nonlinear as above) to follow the deformation direction of tip Grids when the deflections are large? 

Adriano_Koga

Thanks Adriano. 

I played with it and used it.

I am guessing the answer to my second question is adding FLLWER to my input deck with option 1 for concentrated forces/moments. For the CBUSH example, if I want the force follow the the direction of the spring nodes, do I need to define its direction using a local coordinate system?

 

 

correct. By defining a follower force (FORCE2, if I'm not wrong) you specify 2 nodes as reference for the force direction. If their position changes during the NL run, the force will follow this new direction accordingly.