For My study Purpose. I'm doing an

[KAMAL HOSEN]

For My study Purpose. I'm doing an assignments from my school, to structural safety analysis of asteel structure in substtaion. In that assignment I need to report about safety perctages of the structure, like the structure is 100% safe, or 75 or 50% safe. i already analysis the model through STaad.pro, . I can check the all PMM ratio , all are safe, in terms of deflection it's safe. WHat else check i can do and include it to my assignment ? is there any way to tell the safety percentages of a structure? I need the info with Ref. Please Help me. Thanks a lot.

 

[SWComposites]

Because the world is (way over) populated with lawyers, there is no quantification of "safety", nor will you see it documented or discussed. There are "factors of safety" applied to analysis of structures, with those factors specified by codes and regulations; the factors are intended to account for uncertainties and experience and other things. But its black and white - either a structure meets the applicable codes/regulations and thus it is "safe" or it does not meet them, in which case it can be declared "unsafe" by the cognizant regulatory agency.

 

[XR250]

The other one I get a lot from customers -- "Is this structurally sound?"

 

[Geoff13]

I believe this should be in the student posting area, but I'm going to respond since it isn't the actual homework.

What is meant by "safe"? If I calculate the failure load of a structure as 100 (without any units specified) and I intend to load it with 99, is the structure "safe"? Hopefully everyone would agree that's not safe. So how far below failure is "safe"? Every Code takes a different view of this, based on their beliefs about the likelihood of inherent defects, probability the actual loads will be higher than the design values, the consequences of failure, etc. Safe (defined as how close to failure under expected loading) for the garden shed in my backyard is very different from safe for a nuclear reactor.

What is the definition of "safety percentage"? Assuming we've come up with an answer for the first question, and we calculate the Code permitted load is 50 and I intend to apply 49 : Is the structure 98% safe (intended load as percent of permitted load), 102% safe (permitted load divided by intended load), 2% safe (amount the intended load can increase before reaching the permitted load) or something else? I might say "the design loading doesn't exceed 98% of the Code allowable" but would prefer not to summarize a structure down to a single statement.

You stated :
[ul]
[li]I can check the all PMM ratio , all are safe - NO. All you can state is they are within your Code allowables. I could pick a different Code and find these same values don't meet my Code. Does that make the structure "unsafe" even though it meets your Code rules?[/li]
[li]... in terms of deflection it's safe. - NO. Same explanation.[/li]
[/ul]

You can guess that I don't like "safe" or "safety percentage", and would avoid both.

 

[ThomasH]

I think you should skip 50% safe or whatever percent you say. The structure does or does not meet the codes requirement. And then you can use "% utilization" instead of "% safe"

And the question should probably be in the student forum .