Altair RISE

A program to recognize and reward our most engaged community members

Nominate Yourself Now!

Pin hinge and torsion spring

Hi,

what is the procedure to define pin hinge with torsion spring in Radioss with similar functionality as in Motionsolve?

In the file attached bellow I have modeled continuous pin (piano) hinge through type 2 contact with spotflag=4. This works great except there is no option to define small translational compliance (play in the hinge) or joint friction. The other option is to define the hinge through Kjoint2 spring, which requires rigid body on adjacent elements that adds artificial stiffness.

How can torsion spring with rotational stiffness, damping, free angle and preload be added on pin joints?

Unable to find an attachment - read this blog

Find more posts tagged with

English

Radioss

Accepted answers

All comments

Altair Forum User

Hi Ivan,

Can you try with TYPE 33 Kjoint?

Simon Križnik

Hi,

thanks for the hint.

How to model torsion spring (similar to Motionview):

-Produces a moment between two bodies that is a function of the relative angular displacement and the relative angular velocity between the two bodies.

-Free Angle specify the angular displacement produced when a torque is applied to the linear torsion spring.

Altair Forum User

Hi, @Ivan!

i'm too interesting in hinge connector.

did you solve it issue?

how did you model it?

i'm trying with kjoint, but it doesn't work.

Have you any idea about it?

Altair Forum User

Hi,

Sorry, I missed this question.

I think type 8 or type 13 should do.

Altair Forum User

i see,

type spring_8 works well, but how to use kjoints? it's reall hard work!

i have been trying all evening... and i had failled=(

i want to do just simple hinge with one rotation DOF (revolute joint), but i can't=(

@Prakash Pagadala could you show how to?=)

Unable to find an attachment - read this blog

Simon Križnik

Hi Mrt,

I did not yet solve the torsion spring in hinge connector.

The procedure to create kjoint is descibed in https://forum.altairhyperworks.com/index.php?/topic/14759-kinematic-constraints/&tab=comments#comment-39258

There is also a youtube video about kjoint2:

Simon Križnik

Hi Prakash,

there is rotational stiffness definition for both type 8 and 13 spring. This creates a torsion spring with free angle the same as initial angle. However, I am looking for the rotational spring which is preloaded at the initial time step and tends to open towards free angle, that is different form the initial angle.

Altair Forum User

Hi @Ivan

There is an enhancement request already exists for pretension on torsion spring and it should be available in the future version,

As a workaround, try SPR_BEAM (Type13) with a shifted curve for the say, 1st rotational dof (x-axis rotation)

Altair Forum User

If you are looking for something like attached, please let me know,

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Is it kjoint_45?

Altair Forum User

HI,

It is using spring type 13.

Files are attached for reference.

Unable to find an attachment - read this blog

Altair Forum User

thanks, @Prakash Pagadala.

i got an answer from support about kjoint_45. it doesn't work correct if you connect 2 RB and use automatic stiffness for rigid DOFs.

Altair Forum User

@Mrt

Could you please share details about what you have done with Kjoint 45?

Does it has any torsion on it?

Altair Forum User

@Prakash Pagadala

it wasn't about your model.

i was interesting at kjoin_45, but i couldn't find the answer in the forum how does kjont_45 work. i've been writing to support for 2 weeks, but they sent me presentations that consist the information from user_guid and tutorial.

But Hueseyin Cakir had checked my model then connected to development team. it willbe fixed in the next radioss release.

Altair Forum User

Hueseyin has done presentation about it.

Unable to find an attachment - read this blog

Altair Forum User

@Mrt

OK, let me track that.