How to manage the model of a truss

Altair Forum User

Hello, 

I'm working on a optimization of a steel element: I have a truss (traction and compression) rod that connects to the element to be optimized.

My question is how should I consider the axial force on my rod (is a hollow circular section rod)? 

The hub in which the rod is raised is non-deformable, how can I set this element? How can I connect this hub to the element to be optimized so that the forces are transmitted?

How can I match the mesh of the two different components?

Thank you very much

 

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tinh

You can connect it by RBE2

(Panel 1d>rigid)

Altair Forum User

Hi albertolazzeri

 

You can create rigids and apply force as shown to an hollow cylinder.

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

 

Also, i see there is no connectivity between the hollow cylinder and surrounding elements. To have the connectivity, delete the surrounding elements (only one layer of elements, which is marked in red), then create elements manually using Ruled option in 1D page.

 

Thank you

Altair Forum User

Thank you very much for your suggestions, is correct to create a RBE2 in a middle node inside the hollow and connect it to the internal surface of the cylinder?

Which is the difference between your method and my test? I want to study the condition in which the cylinder is non-deformable. If instead I wanted to include the cylinder in the optimization of the element connected to it, what I have to change in the setting?

Thank a lot

Altair Forum User

Altair Forum User said:

If instead I wanted to include the cylinder in the optimization of the element connected to it, what I have to change in the setting?

The elements which you want to optimize Define it as a design space and the cylinder which you don't want to be affected define it as a non design space.

 

Please refer our eBook  'Practical Aspects of Structural Optimization (A Study Guide)'. Where, we have explained each and every optimization technique in detail.

You can download the book from below link.

https://altairuniversity.com/free-ebooks-2/free-ebook-practical-aspects-of-structural-optimization-a-study-guide/ 

 

Below example in OptiStruct help section is similar to your problem. Please refer.

OS-T: 2010 Design Concept for an Automotive Control Arm

 

 

Thank you

 

 

Altair Forum User

Thanks for the advices, I'm already trying to follow the ebook but sometimes external suggestions are useful to avoid wrong choices.

The example you told me  is what I need.