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Beam Three Supports Concentrated Load Formulas and Calculator

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Beam Three Supports Concentrated Load between two supports, Moments, Shear and Reactions Equations and Calculator.

Continuous beam of two equal spans - concentrated load, P, at center of one span Calculator.

Beam Three Supports Concentrated Load between two supports
Figure 1 Continuous beam of two equal spans Indeterminate Beam

Preview: Beam Three Support Two Loads Calculator

Reactions:

Eq. 1
R1 = [ ( P · b / 4 · L3) ] ( 4 · L2 - a ( L + a ) )

Eq. 2
R2 = [ ( P · a ) / ( 2 · L3 ) ] ( 2 · L2 + b ( L + a ) )

Eq. 3
R3 = [ - ( P · a · b ) / ( 4 · L3 ) ) ( L + a )

Shear forces:

Eq. 4
V1 = ( ( P · b ) / ( 4 · L3 ) ) ( 4 · L2 - a ( L + a ) )

Eq. 5
V2 = ( - ( P · a ) / ( 4 · L3 ) ) ( 4 · L2 + b ( L + a )

Eq. 6
V3 = ( ( P · a · b ) / ( 4 · L3 ) ) ( L + a )

Bending moments:

Eq. 7
Mmax = ( ( P · a · b ) / ( 4 · L3 ) ) ( 4 · L2 + a ( L + a ) )

Eq. 8
MR = ( - ( P · a · b ) / ( 4 · L2 ) ) ( L + a )

Where

P = Concentrated load, lbf/in (N/m)
L = beam length, in, (m)
a = distance, in (m)
b = distance, in (m)
R1, 2, 3 = reaction at support , lbf (N)
V1, 2, 3 = shear forces lbf, (N)
MR, max = bending moments, lb-in, (N-m)

Related

Source

Civil Engineering Reference Manual, Fifteenth Edition, Michael R. Lindeburg, PE