## Deflection Equation for Composite Beam with Moment Connections

## Deflection Equation for Composite Beam with Moment Connections

(OP)

I need some help with a composite beam that has moment connections. The examples in the ASD manual calculate deflection of a composite section as ML^2/161I, but their example follows a beam with a pinned connection.

Do the steel beam connections themselves play a part in the derivation of this deflection equation? And if they do, how can I find/derive the equation that takes into account a fixed connection as opposed to pinned?

Any help would be great.

Thanks-

P333

Do the steel beam connections themselves play a part in the derivation of this deflection equation? And if they do, how can I find/derive the equation that takes into account a fixed connection as opposed to pinned?

Any help would be great.

Thanks-

P333

## RE: Deflection Equation for Composite Beam with Moment Connections

For a single member, moment-area is probably straightforward.

## RE: Deflection Equation for Composite Beam with Moment Connections

## RE: Deflection Equation for Composite Beam with Moment Connections

## RE: Deflection Equation for Composite Beam with Moment Connections

PanamaStrEng: Only the steel beam is connected to columns with moment connections, and the slab is only composite with the beam.

Thanks!

## RE: Deflection Equation for Composite Beam with Moment Connections

## RE: Deflection Equation for Composite Beam with Moment Connections

I agree that for a reliable solution, a computer analysis is best here, breaking the span up into segments of appropriate E and I values

Mike McCann

MMC Engineering

## RE: Deflection Equation for Composite Beam with Moment Connections

I have done this a couple of times before with concrete beams, you can use moment area to find deflections prior to cracking, at cracking, at yield, and at ultimate by plugging in the inertia changes along the beam at the affected locations then using moment area. Or you can do it with a computer program.

If it is a new beam, what I would do is design it to satisfy gravity deflection requirements using a pin-pin assumption and go home.