For my undergrad dissertation im using threaded rods instead of a conventional welded stiffener to stiffen the compression zone in a beam column moment connection. The bolts in the bottom of the end plate are replaced wit threaded rods and run throught the column and attached to both flanges of the column. I am trying to calculate how much of the load is taken by the rods and how much by the web of the column. Any help would be appreciated
Stiffening of Moment Connection
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wilheldp_PE
PE, LEED AP, SPAM KING
Innuendo and out the other.
Skip,
All bad puns aside, why not simply look at the moment of inertia of the cross section and look at where the stress is comming from?
Also, is this funded by NEHRP or something? Typically, rods don't function too well as bracing members undergoing moment reversals during seismic events. Also, many rods are fracture critical, so I would worry about the tension face of the beam-column connection.
All bad puns aside, why not simply look at the moment of inertia of the cross section and look at where the stress is comming from?
Also, is this funded by NEHRP or something? Typically, rods don't function too well as bracing members undergoing moment reversals during seismic events. Also, many rods are fracture critical, so I would worry about the tension face of the beam-column connection.
PeonPE
Peon, 2nd Class
I don't know if the barn yard general purpose construction all-threads your propsoing to use are the same class of steel a higher end ASME / ANSI class bolt will have. I just think they will be so flexible they simply won't add the rigidity to the web or displace the load that your looking for. That being said stiffeners are used to prevent the webs from buckling and simultaneously serve to give some extra strength to the stop the flanges from warping. My understanding is that stiffeners don't "take on the load" in the traditional sense but rather increase the capacity of the beam by keeping it from buckling. So you're not looking to subract some of the load from the web, rather you want to look at when the elastic zone buckling threshold begins as a result of your modified geometry.
Imagine putting a small beam in a compressive test machine loaded axially and loading it until it buckles. Now put transverse loads on the center of each side of the web and do the same test. You can load it just a but more before it buckles. You haven't changed the ultimate compressive strength of the beam, but you've prevented it from buckling as fast.
Kevo is right on about rods / cylinders.They load to a certain point then fail completely.
Not sure if that helps but I'd spend some more time mulling it over before you go too crazy with any equations.
Imagine putting a small beam in a compressive test machine loaded axially and loading it until it buckles. Now put transverse loads on the center of each side of the web and do the same test. You can load it just a but more before it buckles. You haven't changed the ultimate compressive strength of the beam, but you've prevented it from buckling as fast.
Kevo is right on about rods / cylinders.They load to a certain point then fail completely.
Not sure if that helps but I'd spend some more time mulling it over before you go too crazy with any equations.
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