Beam Loads - Support Force Calculator

Calculate beam load and supporting forces.

Beam - loads and support force

Online Beam Support Force Calculator

The calculator below can be used to calculate the support forces - R₁ and R₂ - for beams with up to 6 asymmetrically loads.

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For a beam in balance loaded with weights (or other load forces) the reactions forces - R - at the supports equals the load forces - F. The force balance can be expressed as

F₁ + F₂ + .... + F_n = R₁ + R₂ (1)

where

F = force from load (N, lb_f)

R = force from support (N, lb_f)

In addition for a beam in balance the algebraic sum of moments equals zero. The moment balance can be expressed as

F₁a_f1 + F₂a_f2 + .... + F_na_fn = R a_r1 + R a_r2 (2)

where

a = the distance from the force to a common reference - usually the distance to one of the supports (m, ft)

Example - A beam with two symmetrical loads

A 10 m long beam with two supports is loaded with two equal and symmetrical loads F₁ and F₂, each 500 kg. The support forces F₃ and F₄ can be calculated

(500 kg) (9.81 m/s²) + (500 kg) (9.81 m/s²) = R₁ + R₂

=>

R₁ + R₂ = 9810 N

= 9.8 kN

Note! Load due to the weight of a mass - m - is mg Newton's - where g = 9.81 m/s².

With symmetrical and equal loads the support forces also will be symmetrical and equal. Using

R₁ = R₂

the equation above can be simplified to

R₁ = R₂ = (9810 N) / 2

= 4905 N

= 4.9 kN

Related Mobile Apps from The Engineering ToolBox

Beam Supports App

- free apps for offline use on mobile devices.

Example - A beam with two not symmetrical loads

A 10 m long beam with two supports is loaded with two loads, 500 kg is located 1 m from the end (R₁), and the other load of 1000 kg is located 6 m from the same end. The balance of forces can be expressed as