End Plate thickness for Moment Connection 1

[fbaxley]

I'm calculating the thickness of an end plate as part of a Bolted Unstiffened End Plate connection using FEMA 350 guidelines. In section 3.6.1.1, step 4 there is an equation for tp. In the equation there is a variable pt which is not illustrated in the figure 3-14. Does anyone know what dimension pt is referring to or is it a typo?

Thank you for your help!!

 

[J1D]

What is FEMA 350? Is pt the bolt pitch, if you don’t have this dimension in the calculation equation.

 

[VirtualEngineer]

J1D,

The FEMA-350 states:

"The various parameters used in the equations are defined in Figure 3-14 and in AISC-LRFD."

Have you checked AISC-LRFD? I don't have a copy so somone else may have to give you that information if you don't have the LRFD manual either.

Regards,

JPJ

 

[fbaxley]

FEMA 350- Recommended Seismic Design Criteria for New Steel Moment-Frame Buildings. The equation has a pf and a pt. pf is shown in the figure 3-14 as distance from centerline of bolt to top of beam. It does not shown anything about pt.

 

[VirtualEngineer]

Here is the link to the FEMA-350 in case anyone needs it.

http://www.fema.gov/pdf/hazards/earthquakes/nehrp/fema-350ch3.pdf

Regards to All,

JPJ

 

[fbaxley]

VirtualEngineer,

I have vol. 1 of LRFD but I believe I need vol. 2 for the seismic considerations of moment frames.

since you have fema 350, my question relates to equation 3-20 on page 3-47. What do you suppose pt is?

thanks!

 

[VirtualEngineer]

fbaxley,

I can't figure out pt, but there is a great seismic end plate design guide downloadable from AISC, free if you are an AISC member.

With the resources now available to AISC (and ACI) members, it is getting to be almost necessary to become a member of both these organizations.

We all need to get our companies to pay for the memberships and I expect that over the next few years it will be expected standard procedure.

Here is the link to the Design Guide #4 I am talking about.

Notice that the Guide is revised from the original printing from several years ago.

http://www.aisc.org/Template.cfm?Se...aggedPageDisplay.cfm&TPLID=21&ContentID=22619

Regards,

JPJ

 

[VTPE]

The dimension "Pt" equals the distance from the top of the top flange to the centerline of the bolts BELOW the top flange. "Pf" = the distance from the top of the top flange to the centerline of the bolts above (or the bottom of the top flange to the centerline of the bolts below.)

This info is available in the Errata to FEMA 350, file 3-48.pdf.

Note that a LOT of info is changed in the Errata. There are at least 24 pages changed each with at least (1) change. There are (5) diagram changes, at least a half dozen formula changes. It becomes a nitemare if you do not have the latest info. You can get a free download of the errata list by going to the AISC website (

http://www.AISC.org)or

going to this link:

http://www.aisc.org/template.cfm?template=/ContentManagement/ContentDisplay.cfm&ContentID=2777

The updated diagram you are looking for is in this list.

Hope this helps

 

[fbaxley]

Thank you very much VTPE. That is exactly what I needed.

Thank you also VirtualEngineer.