Scan-and-Solve for Rhino

Simulate Early, Simulate Often... In Rhino

# Displacement results question

Greetings,

Firstly many thanks for letting us trial your software, it looks very promising.

Regarding the results, please check the attached .png image.

If we consider the total length of the object being tested (785mm) and the maximum displacement of said object (1.3mm) we can say that the displacement overall falls within the linear space for the steel being used.

Would you agree with this statement?

However what raises a question for me, because the object is composed of parts - to really be sure should we look at the displacement of every part in the assembly and conclude that some of them fall out of linear space and that this has an impact on the validity of the whole calculation.

(for example the mounting laser cut piece next to the number 1 on the image that has 1.2mm of displacement)

All parts are in bonded contact and were tested together in a single scenario.

Many thanks.

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### Replies to This Discussion

Hi V.A.,

Looking at the displacement for the violation of linear elasticity assumption can be misleading, as it measures the total deformation from the restraint. So a tiny deformation, for example, at the cantilever beam base, can lead to a large displacement at the tip. If we had a small bracket bonded at the tip, the displacement of that bracket will be high even though it's not experiencing any strain.

To ensure that you are in the linear range, you should look at the magnitude of the strain (you can look at the principal/max strain for simplification) and ensure that it's around ~.o1 or smaller (theory says much smaller than 1). For more information, you can check out this wiki article about the infinitesimal strain theory https://en.wikipedia.org/wiki/Infinitesimal_strain_theory. I have also attached a screenshot of the relevant portion from the wiki page.

I also wanted to point out that, even when you are outside the linear range, the linear elasticity solution could still be useful, for example, in locating regions of interest (like stress concentration) and finding the nature of deformation.

I hope this helps!

G Kumar,

Intact Solutions, Inc.

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Dear Mr. Kumar

Many thanks for your clarifications, I will discuss this further and get back to you with any further questions.

We have also bought a license and will be conducting more tests.

No problem. Let us know if there are any more questions.

Greetings,

I would have one more question - this one regarding the sub-element contact within the simulation.

Please take a look at the bolted contact image - I would need to have a bolted contact between these 2 sheets rather than a bonded one. Would that be possible?

Also please consider on the second picture attached (the leftmost image) the screw simulated as two equal and opposite forces (to simulate friction) - would that make sense?

Also while going through the manual I noticed thermal simulation - is that an additional plugin being developed? - as we could use that as well.

Many thanks.

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Hi V.A.

I apologize for not responding earlier. Somehow missed the notification. Below are my comments to your question.

1. Unfortunately, we only support bonded contact right now.

2. You can simulate the screw with two opposite loads applied, but we need a some portion of the screw to be restrained for a stable linear system during solving. So you can restrain a small region which you think should not affect the result you are after. Let us know if you need more help.

3. We are working on a grasshopper plugin which has support for additional physics including thermal. We will send emails and mention on our website once it is released.