1. Horizontal Shear Stress in Beam
Lecture Number - 05
D.B. Raut
Mechanical Engineering
SINHGAD COLLEGE OF ENGG ,Vadgaon
Strength of Materials

2. Average Shear Stresses in Beam
Average vertical shear stress in beam is defined as
Vertical shear force can be determined from shear force diagram
The shear force is purely function of the loading only i.e. It does not depend on material properties and section of the beam
Thus average shear stress depends on loading and sectional area of the beam
Strength of Materials

3. Maximum Shear Stress in Beam: Rectangular Section
Shear stress at a distance y from neutral axis is given by
Substituting following values in above equation
Strength of Materials

4. Maximum Shear Stress in Beam: Rectangular Section
Simplified expression for shear stress is
Hence for maximum shear stress in rectangular beam is 1.5 times average shear stress and it occurs at neutral axis
Strength of Materials

5. Shear Stresses in Beam For circular cross section
Strength of Materials

6. Shear stress in beam: Numerical
Q. A beam AB of span 3m and width 90 mm is loaded as shown in the diagram. Knowing σall=12MPa, and τall=0.8Mpa, determine minimum depth ‘d’ of the beam
SFD and BMD are shown in the diagram
Maximum Shear force and Bending Moment are-
Strength of Materials

7. Strength of Materials

8. Shear stress in beam: Numerical
Design based on allowable Normal Stress
Strength of Materials

9. Shear stress in beam: Numerical
Design based on allowable Shear Stress
Thus in order to keep shear as well as normal stresses within allowable limits minimum depth of the beam must be 322 mm
Strength of Materials