Question

A simply supported beam of length 3 m and
carrying a UDL of 4kN/m, find
1. Maximum bending stress in the beam
2.Maximum shear stress in the beam.
3.The shear stress at point 1 m to the right of the left support and 25 mm below
the top surface of the beam​

Answer 1

Answer:

Step 1: Data:

Length of beam = 2m or 2000mm

load at failure = 2KN

Section dimensions = 40mm X 60mm

Step 2: Calculation of moment of inertia

I = bd3/12

 = (40) (603)/12

 = 7.2X105 mm4

Step 3: Calculation of bending moment about fixed end

M = WL

   = (2)(2)

   = 4KN-m

Step 4:

Calculation of bending stress

M /I= σ / y

Substitute for above (where y = depth /2= 60/2 = 30mm)

There fore  

σ = 166.67N/mm2

Explanation: