A 2 m long beam BC carries a single concentrated load at its mid span and is simply supported at its end by two cantilevers AB = 1m long and CD = 2m long as shown in figure. The shear force at end A and bending moment at end D of the cantilever, respectively will be -
A 2 m long beam BC carries a single concentrated load at its mid span and is simply supported at its end by two cantilevers AB = 1m long and CD = 2m long as shown in figure. The shear force at end A and bending moment at end D of the cantilever, respectively will be - Correct Answer 50 KN, 100 kNm
Explanation:
The given beam is:
[ alt="F3 Madhuri Engineering 24.06.2022 D9" src="//storage.googleapis.com/tb-img/production/22/06/F3_Madhuri_Engineering_24.06.2022_D9.png" style="width: 226px; height: 124px;">
Consider FBD of beam BC:
[ alt="F3 Madhuri Engineering 24.06.2022 D10" src="//storage.googleapis.com/tb-img/production/22/06/F3_Madhuri_Engineering_24.06.2022_D10.png" style="width: 244px; height: 144px;">
Σfy = 0
RB + RC = 100
ΣMB = 0
RC × 2 = 100 × 1
⇒ RC = 50 kN and RB = 50 kN
Consider FBD of beam AB and CD:
[ alt="F3 Madhuri Engineering 24.06.2022 D11" src="//storage.googleapis.com/tb-img/production/22/06/F3_Madhuri_Engineering_24.06.2022_D11.png" style="width: 209px; height: 163px;">
ΣFy = 0 ⇒ RA = 50 kN
ΣMA = 0 ⇒ 50 × 1 = MA
= MA = 50 kN.m
shear force A is reaction at A i.e. VA - RA = 50 kN.
[ alt="F3 Madhuri Engineering 24.06.2022 D12" src="//storage.googleapis.com/tb-img/production/22/06/F3_Madhuri_Engineering_24.06.2022_D12.png" style="width: 209px; height: 160px;">
ΣFy = 0
⇒ RD = 50 kN
ΣMD = 0
⇒ 50 × 2 = MD
MD = 100 kN.m
BM at D is MD = 100 kN.m