Springs with variable stiffness property
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?
Best Answer
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Javid Moraveji said:
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.
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Altair EmployeeAnswers
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hi,
both CBUSH/PBUSH and CBUSH/PBUSH1D have the option of using a NL force x displcaement curve (TABLED1) and assign it to the NL stiffness KN;
/try this one, attached
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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?
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Javid Moraveji said:
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.
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Adriano A. Koga_21884 said:
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.
sorry..FORCE1
https://help.altair.com/hwsolvers/os/topics/solvers/os/force1_bulk_r.htm
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