Addition of cbush type connector

Feature Requests
1

Hello,

First, thank’s for the great job that you are done to develop this very useful software

Can you please add some connector for assembly analyses.

CBush connector equivalent can allow to simulate a lot of connexion.

Thanks a lot for tour reply

2

CalculiX has 2-node spring and dashpot elements that should be equivalent to this connector but they are not available in PrePoMax yet and have to be added via Keyword Editor: Spring between two nodes

3

Hello,

CBush is 6 DOF. If we want to simulate a spherical joint for example. We can define the stiffnesses k4, k5, k6 equal to zero.

I don’t know if SpringA allows you to do that.

Is there a way to do this on calculix?

Thanks

4

In CalculiX, there are translational springs (you can use 3 of them to define stiffness in each translational direction). Rotational springs can be created by attaching springs to rigid body ROT NODE.

Check this recent discussion: Creating Joints on assembly meshes - #23 by Sound_Spinning

CalculiX indeed doesn’t have proper joints but you can often achieve the desired result with simpler elements and constraints that are available in this solver.

5

Thanks for tour reply. I will explore this.
So if i correctly understand:

3 Spring1 for translation with Infinite regidity
3 Spring2 for rotation with 0 regidity for rotation

I will create a model and i will check if it work’s

6

When it comes to spring element types in CalculiX, here’s how they differ:

  • SPRING1 - spring to ground (1 node), acts in the specified direction
  • SPRING2 - spring between 2 nodes, acts in the specified direction
  • SPRINGA - spring between 2 nodes, acts along the line connecting both nodes

In all the cases, you have to provide stiffness but formally only DOFs 1 to 3 (translational) are supported. However, if the spring is attached to ROT NODE of a rigid body, they should become rotational DOFs (they are dummy rotational DOFs in CalculiX anyway).

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