Solidedge simulation factor of safety

Experimenter
Experimenter

My frame is a combination which includes more than 2 materials, I did input the different materials properties under Geometry. After done the simulation, the safety factor is only based on main material property but not based on their own yield strengths. Waiting for help.

 

Thanks,

12 REPLIES

Re: Solidedge simulation factor of safety

Phenom
Phenom

This is not an easy issue.

 

Code compliance relative to FEA is a can of worms.

 

Here is the starting point. With liniar structural calculations not directly covered by a code calc, Most PE;s will not stamp stuff with a SF under 4.5

 

This is also overkill that no manufatureing operation wand to use for production.

Then you start hashing it out.

Re: Solidedge simulation factor of safety

Experimenter
Experimenter

sorry, dont really understand. I was using solidworks before, which didnt have this issue. The safety factor will be ultimate stress over work stress, my question is solidedge just regards the main material as the only ultimate stress. But I have other types of material are existing in the frame.

 

Thanks,

Re: Solidedge simulation factor of safety

Pioneer
Pioneer

I understand your problem. Although i'm not sure if you can get SE Sim to give you the FoS for different materials, you could also just hand calc it.. FoS =  Ultimate Tensile Strength/Von mises stress 

 

You can just locate the highest stress in the material and plug'n'chug. Smiley Happy 

"The society which scorns excellence in plumbing because plumbing is a humble activity, and tolerates shoddiness in philosophy because philosophy is an exalted activity, will have neither good plumbing nor good philosophy. Neither its pipes nor its theories will hold water." -- John W. Gardner

Re: Solidedge simulation factor of safety

Experimenter
Experimenter
Thanks, if no better answer, i think i have to get the highest stress and hand calc the FoS..........

Re: Solidedge simulation factor of safety

Phenom
Phenom

@ncsteinb correct me if I'm wrong (I may be, I'm not an expert!) but is FOS not based on Yield strength, rather than Ultimate strength? 

Re: Solidedge simulation factor of safety

Experimenter
Experimenter

You are right. Who said FoS is based on yield strength?

Re: Solidedge simulation factor of safety

Pioneer
Pioneer

My opinion on it is that it depends... 

 

Factor of safety can be if something breaks or fails to work properly.. 

 

In my experience, it's been based on the UTS. But in some cases, if the part yields, it may not perform as expected, and therefore I will use the Yield Stress instead. Ultimately, we are talking about safety, so I think of the point of breaking vs. not breaking, so I use UTS for FoS.

 

Cheers,

Nevin

"The society which scorns excellence in plumbing because plumbing is a humble activity, and tolerates shoddiness in philosophy because philosophy is an exalted activity, will have neither good plumbing nor good philosophy. Neither its pipes nor its theories will hold water." -- John W. Gardner

Re: Solidedge simulation factor of safety

Experimenter
Experimenter

Agree. I dealt with wood frame mostly. For wood, I assuming yield strength is equal to ultimate. Thanks for your help. 

Re: Solidedge simulation factor of safety

Phenom
Phenom

It all depends on the material and design specifics.

 

For steel, it is typically depedent on yeald because past that point, it no longer acts like a spring.

A strucural PE worked for was happy when the steel designs were below 12 to 15 KSI under any condition.

 

A SF of 2.5 can be safe if conditions are very prdictable.

If conditions are not and life safety is involved, I have seen SF of 5 required.