Calculation of Shear force and Bending
moment and Drawing S.F.D and B.M.D
of Simply Supported Beam
The beam with loading is given below:
Calculation for reactions:
As the beam is symmetrical, therefore, each reaction (the support
under the beam) will bear half of the total load on the beam.
RA = Rb = (1500 + 1500 + 1000)/2 = 4000/2 = 2000kg
So each reaction will be 2000kg
Shear Force:
S.F at A = +2000 kg
S.F at C(R) = 2000 - 1500 = 500 kg
[If we take the section to the right side of point ‘C’, then to its left side
all the forces are +2000kg of the reaction force and the -1500kg force
that is acting downwards. For more understanding of signs, check out
my document for the sign conventions for beams.]
S.F at D(L) = 500 - 1000 = -500 kg
[If we take the section at the left side of point ‘D’, then all forces at the
left side of that section will be summed. The U.D.L will be converted to
point load (1000 kg/m * 1 meter = 1000 kg). ]
moment and Drawing S.F.D and B.M.D
of Simply Supported Beam
The beam with loading is given below:
Calculation for reactions:
As the beam is symmetrical, therefore, each reaction (the support
under the beam) will bear half of the total load on the beam.
RA = Rb = (1500 + 1500 + 1000)/2 = 4000/2 = 2000kg
So each reaction will be 2000kg
Shear Force:
S.F at A = +2000 kg
S.F at C(R) = 2000 - 1500 = 500 kg
[If we take the section to the right side of point ‘C’, then to its left side
all the forces are +2000kg of the reaction force and the -1500kg force
that is acting downwards. For more understanding of signs, check out
my document for the sign conventions for beams.]
S.F at D(L) = 500 - 1000 = -500 kg
[If we take the section at the left side of point ‘D’, then all forces at the
left side of that section will be summed. The U.D.L will be converted to
point load (1000 kg/m * 1 meter = 1000 kg). ]
