Related Resources: calculators

Beam Three Supports Uniform Load Deflections Equations and Calculator

Civil Engineering Resources
Structural Design Engineering Resources

Beam Three Supports Uniform Load, Moments, Shear, Reactions and Deflections Equations and Calculator

Continuous beam of two equal spans - uniformly distributed load of w in load/unit length Calculator

Continuous beam of two equal spans
Figure 1 Continuous beam of two equal spans

Preview: Beam Three Support Two Loads Calculator

Reactions:

Eq. 1
R1 = (3/8) w L

Eq. 2
R2 = 1.25 w L

Eq. 3
R3 = (3/8) w L

Shear forces:

Eq. 4
V1 = (3/8) w L

Eq. 5
V2 = ±(5/8) w L

Eq. 6
V3 = - (3/8) w L

Bending moments:

Eq. 7
Mmax = -(1/8) w L2

Eq. 8
M1 = (9/128) w L2

Eq. 9
Maximum deflection:
δ = 0.00541[ ( w L4 ) / ( E I ) ],
Eq. 9a
at x = 0.4215 L

Eq. 10
δ = ( w / ( 48 E I ) ) ( L3 x - 3 L x3 + 2 x4),
Eq. 10a
at 0 ≤ x ≤ = L

Where

w = uniformly distributed load, lbf/in (N/m)
L = beam length, in, (m)
x = location, in (m)
δ = deflection, in (m)
R1, 2, 3 = reaction at support , lbf (N)
V1, 2, 3 = shear forces lbf, (N)
M1, max = bending moments, lb-in, (N-m)
E = Modulus of elasticity lbs/in2, (N/m2)
I = area moment of inertia in4, (m4)

Related

Source

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