How to decide a existing plate girder steel yield stress is 36ksi or 50 ksi?
How to decide a existing plate girder steel yield stress is 36ksi or 50 ksi?
(OP)
I have to check a existing plate girder capacity. How could I decide the steel plate yield stress? I know normally it is A36, but it looks like it does not work for my load and I suspect they are 50ksi plates. Is there any way to test? Thank you.






RE: How to decide a existing plate girder steel yield stress is 36ksi or 50 ksi?
There is a difference btwn. checking that plate girder for its intended loading and its max. cap’y. Try honing in on what the original loading was, and then check it and see what works. It sounds like you’ve kinda done that. Alternatively, it is not (was not) uncommon to design the flanges with 50ksi stl. and the webs with A36 mat’l. In the old ASD methods I always felt it was o.k. that the upper/lower few inches of web mat’l. might yield a little bit and just sluff some of their load/force off onto the flgs. The web really can’t go anyplace, it is constrained by the flg. as long as the flg. doesn’t yield much. Finally, find someplace on the girder, probably out near the bearing ends, where you can have a lab take some samples of the flgs. and web for chemical and tension tests. They can then tell you what ASTM Spec. the mat’l. meets. Obviously, you still have to check girder stability, web crippling and buckling, stiffener spacings, etc.
RE: How to decide a existing plate girder steel yield stress is 36ksi or 50 ksi?
RE: How to decide a existing plate girder steel yield stress is 36ksi or 50 ksi?
RE: How to decide a existing plate girder steel yield stress is 36ksi or 50 ksi?
RE: How to decide a existing plate girder steel yield stress is 36ksi or 50 ksi?
The cheapest and likely easiest option is to contact the owner of the girders and gain access to the original drawings. Certainly, they would have called out the material specifications on the original drawings.
RE: How to decide a existing plate girder steel yield stress is 36ksi or 50 ksi?