topic Re: Generative Design - Wrong Safety Factor in Fusion Support Forum

Generative Design - Wrong Safety Factor

Anonymous — Wed, 04 Sep 2019 09:22:56 GMT

Our team has experienced the following problem: the Generative Design outcomes come with a certain Safety Factor. Testing such design outcomes in the simulation environment, under the same loads and constraints, gives a different (always lower) Safety Factor. Why? What FoS should we trust? Do you really want us to spend thousands of dollars into testing a prototype that may have a lower FoS than expected? Is our team missing something obvious or the service you are providing is just flawed and unreliable? How do we solve this problem? Thanks.

Re: Generative Design - Wrong Safety Factor

TheCADWhisperer — Wed, 04 Sep 2019 10:54:28 GMT

What is the definition of Safety Factor?

Re: Generative Design - Wrong Safety Factor

Anonymous — Wed, 04 Sep 2019 15:23:56 GMT

Excuse me? For us there is a difference if a subsea riser clamp designed for the offshore industry can withstand a total weight of 36 thousand Kg or 24 thousand Kg before having a Safety Factor lower than 3.

We had generative design outcomes with a Safety Factor between 3 and 6 and after testing them in the Simulation environment they would have a FoS < 2. Why is that? We have a legitimate question, can you give a proper answer?

If you are genuinely asking for what a Safety Factor is, then please consult the Wikipedia article:

https://en.wikipedia.org/wiki/Factor_of_safety

Re: Generative Design - Wrong Safety Factor

bmfrank — Thu, 05 Sep 2019 13:23:38 GMT

Without seeing the results I don't know the answer for this specific case, but there are some things to check. Sometimes when the geometry conversion takes place the method that is used to join your preserve geometry with the geometry generated can result in features that may introduce stress concentrations. These stress concentrations are not present in the synthesized geometry solution, but the method for creating editable geometry might introduce them. These may yield a lower safety factor than what is computed during the geometry synthesis. In this can you can likely edit the geometry (adding fillets or chamfers, modifying blends) to remove the likelihood of creating stress concentrations. Alternatively, you could download a mesh/stl version of the outcome and use this as the basis for design. Feel free to DM me or post additional information here if needed.

Re: Generative Design - Wrong Safety Factor

TrippyLighting — Thu, 05 Sep 2019 21:15:34 GMT

@Anonymous wrote:

We have a legitimate question, can you give a proper answer?

Then provide relevant data in form of a model and workflow description. Screencasts are a very helpful tool.

What other software and methods are you using to verify results ?

Re: Generative Design - Wrong Safety Factor

Anonymous — Thu, 05 Sep 2019 23:55:46 GMT

Thank you. Please allow our team a couple of days to prepare the data. I appreciate the support.

Re: Generative Design - Wrong Safety Factor

Anonymous — Thu, 05 Sep 2019 23:59:26 GMT

Your reply was very useful, thank you. Our team will test the recommendations you have suggested.