Learning Forum

[Anavasquez91]

Hello, 

I have a question about a  result of safety factor.

I know that the safety factor is yield stress/largest VM stress in model.

But in my simulation i dont know why the result is not correct:

 The result of (von-misses) stress was: 62,441Mpa

The result of safety factor was: 3.1

but is not correct because would be: 250/62,441 = 4

I dont know what is the porblem, If someone can help me.

[parkersheaffer]

Put a probe in your SF plot at the location where your maximum stress is occurring, also put a probe in to show where the minimum SF is occurring. Do these locations match? If they do verify that the component where the minimum SF occurs uses the steel you posted above. My guess is you have other materials in the model and the minimum SF is occurring on a material with a lower yield.

[Anavasquez91]

Hello, 

Thank you for your answer.

It is true that i used two different materials in this simulation. I put a probe in minimum and maximum  where the safety factor is ocurring, this is the image, the value is diffetent than previosly beacuse i changed the values of forces, but still is different than  yield stress/largest VM stress.

So my question is what method use Ansys to calculate in this case tha safety factor because is different than this form(yield stress/largest VM stress)?

For this case the largest VM stress is: 43,42 Mpa

Thank you!

[peteroznewman]

The Safety Factor under the Stress Tool allows you to choose between Yield and Ultimate Strength. Please show what your choice was in the Details window.

[Anavasquez91]

To this simulation i used Tensile Yield Per Material

Thank you, if someone can help me!

[peteroznewman]

If you create an Archive .wbpz file and attach it to your reply, and say what version of ANSYS you are using, I will look at the solution and look at how the yield strength is divided by the max equivalent stress and compare that with the Safety Factor.

The .wbpz file must be < 120 MB to attach. Do not save results. If it is too large without results, you also have to Clear Generated Data on the Mesh to make the file as small as possible.

[Anavasquez91]

The simulation is in V.15.

The attach did not work, i dont know why? 

if you could give me your email or something to search the file.

 

[peteroznewman]

What is the file name you tried to attach?