Question

4. A simply supported beam 7m long is carrying three point loads of 100N.
600N and 175N at 2m, 4m and 5.5m from the left support. Determine
support reaction and draw SFD and BMD.​

Answer 1

firstly we need to find the support reactions using the equations of equilibrium ( ΣFy = 0 , ΣM = 0 )

let the support reaction be Ra , Rb ;

ΣFy = 0

⇒ Ra + Rb -( 600 + 175 +100 ) = 0

  ⇒ Ra + Rb = 875N _______(1)

ΣMa = 0

⇒ (100 x 2) + (600 x 4) + (175 x 5.5) - (Rb x 7) = 0

⇒ Rb = 508.928 N

from (1) ⇒ Ra = 875 - 508.928 = 366.072N

SFD and BMD are pinned in the attachment    

     

Hope this helps you !!