Allowable Stress Increase for Impact Loading??
Allowable Stress Increase for Impact Loading??
(OP)
I am designing a steel beam that will have an impact load. After impact, the load will almost instantaneously go to zero. I was told that there is an allowable stress increase of 1.6 - 2.0 for these short duration loads. I cannot find anything that supports this increase. Ive looked through the AISC (13th ED.), ASCE 7, and the California Building Code. There are allowable stress increases for impact loads in both the NDS and the bridge manual, but one is wood and I think the other is for concrete.
I could not find anything online either. I was told that AISC 9th ED. had a section that referenced this, but I dont have a copy of that, and if it is no longer in the 13th ED should I still use it??
If anyone knows the reference to a current code or an opinion on whether I should bump the stress for the allowable stress it would help me out a ton! Thanks for your time.
I could not find anything online either. I was told that AISC 9th ED. had a section that referenced this, but I dont have a copy of that, and if it is no longer in the 13th ED should I still use it??
If anyone knows the reference to a current code or an opinion on whether I should bump the stress for the allowable stress it would help me out a ton! Thanks for your time.






RE: Allowable Stress Increase for Impact Loading??
RE: Allowable Stress Increase for Impact Loading??
http://www.modernsteel.com/Uploads/Issues/July_201...
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RE: Allowable Stress Increase for Impact Loading??
"Allowable stresses may be increased 1/3 above the values otherwise provided when produced by wind or seismic loading, acting alone or in combination with the design dead and live loads, provided the required section computed on this basis is not less than that required for the design dead and live load and impact (if any) computed without the 1/3 stress increase."
RE: Allowable Stress Increase for Impact Loading??
Smhetrick, that section was removed in a supplement to the 9th edition specification.
RE: Allowable Stress Increase for Impact Loading??
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