A contilever beam of length 2 m fails when a load of 2 kn is applied at the free end. if the section is 40 mm * 60 mm, find the stress in the failure.

 

A contilever beam of length 2 m fails when a load of 2 kn is applied at the free end. if the section is 40 mm * 60 mm, find the stress in the failure.

1)Given data- beam length l = 2m. =2000mm

load at free end P = 2 kn = 2000 Newton.

cross section 40 * 60 mm

b = 40 mm

d = 60 mm

2) calculate bending moment at fixed end

so M= P*L

2000*2000

= 4* 10^6 N/mm

3)Moment of inertia of rectangular section

I = bd3/12

40*60^3/12

720000mm4

4) Distance for neutral axis

y=d/2

60/2

= 30 mm

5) calculate bending stress 

σ = M*y/I

4*10^6*30/72000

= 1666.67 n/mm2