Safety Factor
Safety Factor
(OP)
I have a general question regarding safety factors. If you have sufficient test data for products/structural elements to failure, what value of safety factor would you recommend? I know some are dependant on the mfg., but if no recommendations are given, it is acceptable to us a factor of safety of 2, similar to the safety factor used with ulitimate loads in steel design?






RE: Safety Factor
RE: Safety Factor
Thanks.
RE: Safety Factor
1. Fatigue considerations
2. Use/application
3. Product and material
4. Current code requirements
5. Who did the testing (self serving testing is not very credible in my opinion unless it is done by independent third party)
You can always use engineering judgment. However, I would not depart from normally accepted practices. Few points to ponder.
Regards,
Lutfi
RE: Safety Factor
RE: Safety Factor
DaveAtkins
RE: Safety Factor
There are some questions which may help to inform on the correct judgement:
What is the consequence of failure?
What is the certainty of operation?
Is there a danger to life and limb?
Is there likely to be on-going deterioration?
In establishing a unique factor of safety, are any industry guides being overlooked?
Now as DaveAtkins correctly points out, factors of safety are based on probabilities of exceedence. Limit state concepts (LRFD)utilise partial safety factors on materials, workmanship, service conditions and loading (probably there are others). These all combine to give you a single overall factor of safety. Other design approaches make the assessment of factor of safety more difficult as the individual factors are hidden. It is generally understood that the actual safety factor is higher than the one which is calculated as part of a design. As an industry we are certainly not perfect, and accidents happen far too frequently as a result of incorrect design / detail / material / installation etc.
I would propose that the original question may be somewhat misplaced. It might better to investigate if, through design of the panel, some of the other variables affecting safety could be reduced or eliminated.