1. Shear Stress in Beams
Figure: 07-00CO

2. Shear in Straight Members
Internal shear force – creates shear deformation, strain and shear stress!
Figure: 07-01
Note: due to nature of shear stress get transverse and longitudinal strain.

3. Physical example – when boards glued together, shear stress is developed at surfaces which prevents slippage.
Figure: 07-02a

4. Notice deformation: key point, deformation not uniform!!
Figure: 07-03a,b

5. 6.2 – Shear Stress Formula:
Figure: 07-04a

6. Derivation of Beam Shear Stress Equation:
Figure: d

7. Derivation of Beam Shear Stress Equation (cont’d):
Recall, dM/dx = V
= Q
Internal Shear (lb)
Figure: d
First Moment of area (in3) at point of interest
Thickness of cross-section at point of interest (in)
Moment of inertia of entire cross section (in4)

8. Example: Square Cross-section:
Figure: UN

9. Example: I-Beam
Figure: 07-07a

16. 7-11: Given: A cantilever beam with 35 Kip load at the end
7-11: Given: A cantilever beam with 35 Kip load at the end. Sketch the intensity of the shear-stress distribution acting over the beam’s cross-sectional area and determine the resultant shear force acting on the segment AB.
Question: where would you expect max stress to be? Why would you be interested in shear stress at joint?
Figure: P7.11