topic Re: Trusses analysis in inventor?? in Inventor Forum

Trusses analysis in inventor??

almuhandiswep — Tue, 16 Aug 2022 07:18:02 GMT

As you know, there is a difference between Frames and Trusses.
The Trusses are attached with pins, and the frames are connected by fixed connections (Rigid)، As shown in the attached picture.
In Inventor, the program only analyzes frames as I know.
The question is: Can Trusses also be analyzed in Inventor Professional?
Here I am not talking about Inventor Nastran. It's about the Inventor only.
I watched some videos on YouTube, talking about analyzing Trusses in Inventor. But it turns out in the end that they are Frames.
What do you think?

The topic is very important.
Please help.

Re: Trusses analysis in inventor??

almuhandiswep — Tue, 16 Aug 2022 07:23:04 GMT

@johnsonshiue any Idea.
another question:
Can we used frames to build a bridge, because as I Know trusses are used for this purpose?

Re: Trusses analysis in inventor??

almuhandiswep — Tue, 16 Aug 2022 07:46:21 GMT

@CGBenner any idea please?

Re: Trusses analysis in inventor??

CCarreiras — Tue, 16 Aug 2022 09:30:36 GMT

Hi!

Inventor frame analysis will check the profiles, regardless of their type of connection. The program will consider that they are perfectly connected, even if they don't are in real life.

After studying the frame analysis, you will get some results. You can later isolate the connections (usually a specific model for this task ) and check them with Inventor FEA or Inventor Nastran.

Re: Trusses analysis in inventor??

CGBenner — Tue, 16 Aug 2022 10:49:25 GMT

@almuhandiswep

Can you offer some more information on what you are trying to design & build? Inventor may not be the right tool for you depending on that. For example, Autodesk also offers, as a part of the AEC collection, this Structural Bridge Design software. But it depends on what you are trying to do.

Re: Trusses analysis in inventor??

almuhandiswep — Tue, 16 Aug 2022 11:13:55 GMT

My question is a general question.
Because I found videos on YouTube explaining all this, but they are not accurate.
I didn't know the difference between Frames and Trusses.
And if I ever tried to design a bridge, I would use Frames, because I work on inventor.
Then I learned later that Trusses are what are used to build bridges.
The most important question: does Inventor analyze Trusses?

Re: Trusses analysis in inventor??

almuhandiswep — Wed, 17 Aug 2022 10:19:19 GMT

@Gabriel_Watson

Any Idea please?

Re: Trusses analysis in inventor??

almuhandiswep — Wed, 17 Aug 2022 10:20:56 GMT

@mcgyvr

Any Idea Please?

Re: Trusses analysis in inventor??

almuhandiswep — Wed, 17 Aug 2022 10:22:43 GMT

@JDMather

Any idea please?

Re: Trusses analysis in inventor??

CCarreiras — Wed, 17 Aug 2022 10:47:12 GMT

A truss is a frame... where the elements are disposed like a bundle of frame elements.

Re: Trusses analysis in inventor??

gerrardhickson — Wed, 17 Aug 2022 11:44:10 GMT

Truss is just a sub-category of a frame, or structure or whatever - the terminology is just semantics.

In most FEA Packages - including Inventor's Frame Analysis and Nastran In-CAD, Pin connections can be simulated using beam end releases.

Below is a fully rigid frame - notice a maximum displacement of just over 3mm.

Here is the same frame with the upper right corner released in the RX direction (Rotation around the X-axis) only.
Notice the green text at the beam ends indicating "xxxfxx", this means fixed (x) in the 3 translation directions, free (f) in the RX direction, and fixed (x) in the RY and RZ direction.

Notice also the maximum deflection and deflection shape have changed.

Re: Trusses analysis in inventor??

JDMather — Wed, 17 Aug 2022 12:30:38 GMT

@almuhandiswep wrote:

@JDMather

Any idea please?

Parts are parts.

Geometry is geometry.

The basic geometry is, well, very basic.

My guess is that a lot of these designs were done in AutoCAD.

My guess is that a lot of these designs were done with paper and pencil on a drawing board.

As for analysis - that takes some training and experience that includes physical testing.

Re: Trusses analysis in inventor??

Gabriel_Watson — Wed, 17 Aug 2022 20:36:12 GMT

Inventor or any design CAD package will not be as accurate as you need them to be to formulate the blueprints to any bridge which people are supposed to use. You should talk to a CAD reseller about additional specialized packages to validate your models and have someone experienced (consultants, usually) simulate and double-check the major calculations and safety factor. Even if all of that is done accurately, you still need to account for cyclical loads and failure analysis due to usage over time, which is the most critical and hard to analyze aspect of such type of design.
The main point is: if you criticize Inventor or instructional videos for not being accurate or robust, your question is defined much worse (no example of end-result needed or previous attempts). Calling out every expert here individually cannot solve this if we don't know exactly what problem you are attempting to solve. Inventor is also only meant to give you a general direction in FEA analysis, not validate complex structures but rather approve a certain design approach initially.

Re: Trusses analysis in inventor??

almuhandiswep — Thu, 18 Aug 2022 19:44:42 GMT

Do you mean that "releases" here is as if we put Trusses (Or pins).
Or in other words: do you mean "releases" is the pins?
Your answer here is very important, please, because your answer will be complete.