EBAT75
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Last year there was an extended thread on steel beam design, more particularly Table 3-10, Lb etc etc. (forget that digression on Table 3-6). The main question was what constitutes Lb, whether a steel decking would meet the requirements of continuous bracing and satisfy requirements of Appendix 6 (14th edition), C in the 15th?
The opinions were that most practicing engineers would consider a decking/floor on a steel beam to be continually braced. There are two parts, strength and stiffness of the bracing. Strength is often the focus but depending on the orientation of decking in relation to the beam, stiffness can be more important.
William Segui's Steel Design (4th Edition, I think I have seen) begs to raise doubts on considering a decking/floor on a steel beam to be continually braced. The often quoted eng-tips threads on the subject also go all over the map.
While these practicing engineers may be exercising their judgment adequately in most design contexts (they may be in low seismic, moderate wind areas with little diaphragm loads)), there are instances of beam failures reported during construction even.
There was talk of the 15th edition SCM and 2016 Specs clarifying some of these, but I do not see anything new on those lines. As I have said in that thread, some of the reserve strength from mill tests consistently coming in at about 60 ksi for 50 ksi yield steel, can be masking some of these.
The real purpose of my posting this is to let anyone interested and who has not seen this free webinar know it is available on AISC webpage:
https://www.aisc.org/education/cont...s/beam-stability-bracing-t8-flash-conference/
The opinions were that most practicing engineers would consider a decking/floor on a steel beam to be continually braced. There are two parts, strength and stiffness of the bracing. Strength is often the focus but depending on the orientation of decking in relation to the beam, stiffness can be more important.
William Segui's Steel Design (4th Edition, I think I have seen) begs to raise doubts on considering a decking/floor on a steel beam to be continually braced. The often quoted eng-tips threads on the subject also go all over the map.
While these practicing engineers may be exercising their judgment adequately in most design contexts (they may be in low seismic, moderate wind areas with little diaphragm loads)), there are instances of beam failures reported during construction even.
There was talk of the 15th edition SCM and 2016 Specs clarifying some of these, but I do not see anything new on those lines. As I have said in that thread, some of the reserve strength from mill tests consistently coming in at about 60 ksi for 50 ksi yield steel, can be masking some of these.
The real purpose of my posting this is to let anyone interested and who has not seen this free webinar know it is available on AISC webpage:
https://www.aisc.org/education/cont...s/beam-stability-bracing-t8-flash-conference/
