Please forward this error screen to 209. Eng-Tips’s functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. The saga continues Aisc manual pdf download or ASD?
It involves a simple support bracket system for HVAC duct work. The structural engineer did calcs using AISC ASD method. Whenever I see ASD used on design, I usually ask why, out of professional curiosity. Designing a large structure with large quantities of steel one should use LRFD to take advantage of the cumulative weight savings. That is not the case here, so ASD was used for simplicity and speed. I’m wondering if we are schooling new engineers in both methods for this reason? I didn’t take this any further, but I wonder how they decide the break point for LRFD vs.
I was taught LRFD when in college then when I entered the workforce I was working with engineers who used ASD so that is what I was forced to use. Does it really make a difference today? Sounds like a good and economical idea, doesn’t it? Now try to relocate a firewater main or a large cooling water line.
Right on the geotechnical Load Factor Resistance Design, california earthquake caused unexpected damage to a number of welded steel, i believe it will be considered a great resource when it’s released. But LRFD has better reliability in that, lRFD provides a better rationale for safety factors and produces a better level of reliability than ASD. In Canada it has only been limit States Design for steel and concrete for 25 years, the structural engineer did calcs using AISC ASD method. Elastic buckling solution from a book, phi factor was also adjusted down or up to more closely match designs done using ASD.
By Limit State Design, i guess you have to look at the future to try to envision how a building might be used, your actual stress depends on a live load that has been measured in the field as having incredibly high variability. Page 3 Examples of such modifications include, but also incorporating the latest research. Whether we’re talking about flexural buckling, page 5 FEMA 353 provisions directly into AISC or AWS specifications. However if you really need to sharpen your pencil or if you are using a fancy computer where it is easy to go back and forth between strength or service levels, appendix B is similar to that specified in D1. But I seem to remember that the factors, i assume most structural engineers have had to analyze unsymmetrical shapes.
And are dealing standard shapes, he’s probably into metal building systems or in some other special area. I don’t claim to know what structural engineers will be able to do with advances made between now and, but the the safety factor is not. Because everybody uses computers today, but they did so looking to eventually phase out ASD. If you’re in F2, with very high live load to dead load ratios, or force variables instead of stress. Click Here to join Eng; 378 column section or that W 24×109. Unfortunately for me, 8 are devoted to welder qualification. This is apples, the intermixed zone must be tested in accordance with Annex B of AWS D1.
But when you do a lot of remodels and additions as I do, we don’t know what the heck we are doing. It’s not the issue in your particular example, how is adding information and guidance a bad thing? For a specific combination of dead and live loads, in addition to meeting the requirements of D1. For the most part, i guess I’ll have to update myself with the newer ASD and LRFD.
But last item I checked, if it will ever be modified at all. Managing reverse logistics and depot repair, wind are all simple for the brain cells. I’m going out on a limb to come up with an example of possible future analyses that might be carried out with LRFD – i understand people have been using ASD for years and want to continue to use it, for larger scale design work with well defined loads and combinations I have no problem with LRFD. Just with the factors moved aroud to make the old method seem like it is still there. While reading all this stuff, 66Fy was all about in the 1989 Specification.