Calculating the Total Force on a Beam in the Vertical Direction

Beams are used in many engineering applications to support different types of objects that exert forces on the beam. It is important to know what the total force acting on the beam is. If you know what the total force is, you can find out what type of supports you need to support the beam with the forces acting on it. In this Instructable, you will only analyze a beam with forces acting in the vertical direction.

In many multi-story buildings beams are placed horizontally to support the different floors of the building. The floor of the building exerts a force on the beam. The beam has to have supports to be able to hold up the force of the floor. This Instructable will examine how to find the total force on a beam so that way you can find out how much force your supports will have to provide.

To complete the Instructable you will need something to write with and write on and a calculator. Knowing how to add numbers is required to complete this Instructable. This Instructable should take five minutes to complete.

Step 1: Analyze the Given Forces

Look at the beam and see what direction the forces are acting in.
An arrow pointing upwards represents an upward force and has a positive value.
An arrow pointing downwards represents a downward force and has a negative value.
For the previously mentioned building scenario, the floor would be a downward force on the beam and the supports would be an upward force.

Step 2: Write Down the Given Information

Write down the name of the force along with its accompanying sign (positive or negative) and value.
Each force has a unit after the value. In this case the unit is Newtons (N), a unit of force.
It is important that the same unit system is used for each force because the value of the force changes depending upon which unit system you are in.

Step 3: Add the Forces Together to Find the Total Force

Using your calculator, add all of the forces that you just wrote down to get the total force.
Depending upon the forces given, the total force can be positive, negative, or zero.

Step 4: Interpreting the Total Force

A negative total force means the total force is acting downwards.
A positive total force means the total force is acting upwards.
A total force equal to zero means the upwards and downwards forces cancel each other out.

Step 5: Real Life Application of Total Force

If the total force is zero, no additional support is needed.
If the total force is not equal to zero, you will need additional support to uphold the forces.
In a multi-story building a floor has a downward total force meaning supports with an upwards acting force are needed.

Here are links to more information about this subject: