Beam Design

CE 4106 – Steel Structures Design

Lecture 17

Beam Design1. Compute Mu. A beam weight may be

assumed.

2. Using Zx Tables or Beam Design Charts,

select a shape and check. Repeat if select a shape and check. Repeat if necessary.

3. Check for shear strength. Select a new shape if necessary.

4. Check for deflections. Select a new shape if necessary.

Using Zx Tables

• Use Zx Tables only for beams with lateral support so that Lb < Lp.

M

y

ux F

MZ

φ≥

Using Beam Design Charts• Can be used for all cases.

• Enter curve with:

bu CMand select shape with higher

• Make sure that

bu CM

nMφ

pbn MCM φφ ≤×

Problem 5.10-2Use A992 steel and select the most economical W shape for the beam shown. The beam weight is not included in the service loads shown. Assume continuous lateral support.

Problem 5.10-3Use A992 steel and select the most economical W shape for the beam shown. The beam weight is not included in the service loads shown. Assume lateral support at the location of the point loads and a the ends.point loads and a the ends.