# Beam Deflection Calculations

• Colin Thompson
This is because the simple support only resists vertical loads and does not restrict the rotation of the beam, causing the bending moments to be distributed evenly along the length of the beam. Therefore, the beam deflection can be calculated using the equation for a simple support beam with a uniformly distributed load.In summary, the conversation discusses the calculation of beam deflection on a setup with an "I Beam" resting on the back of two lorry trailers. The support type is determined to be simple supports, which result in zero bending moments at the ends of the beam. The beam deflection can be calculated using the equation for a simple support beam with a uniformly distributed

#### Colin Thompson

Hello,

I am looking for some advice on calculating the beam deflection on a setup described below.

There is an "I Beam" sitting across the back of two lorry trailers with a uniformly distributed load in the middle of the beam.

I am slightly confused as to what type of support this would be if the beam is resting on the back of a flatbed to allow me to perform some hand calculations?

Colin Thompson said:
Hello,

I am looking for some advice on calculating the beam deflection on a setup described below.

There is an "I Beam" sitting across the back of two lorry trailers with a uniformly distributed load in the middle of the beam.

I am slightly confused as to what type of support this would be if the beam is resting on the back of a flatbed to allow me to perform some hand calculations?

These are called simple supports, and assuming there is no friction to support lateral loads, they are similar to roller supports in that the simple support resists vertical loads, such that their forces act in one direction upward on the beam.

PhanthomJay said:
These are called simple supports, and assuming there is no friction to support lateral loads, they are similar to roller supports in that the simple support resists vertical loads, such that their forces act in one direction upward on the beam.
Doesn't this also mean that the bending moments are zero at the ends of the beam?

Chestermiller said:
Doesn't this also mean that the bending moments are zero at the ends of the beam?
Yes

## What is beam deflection?

Beam deflection is the amount of displacement or bending that occurs in a structural beam when a load is applied to it. It is an important factor to consider in structural engineering to ensure the safety and stability of a structure.

## Why is it important to calculate beam deflection?

Calculating beam deflection is important because it helps determine the structural integrity and safety of a building or other structure. It also helps in selecting the appropriate materials and dimensions for the beam to prevent excessive deflection that could lead to structural failure.

## What factors influence beam deflection?

The amount of beam deflection is influenced by several factors, including the type of load applied, the material properties of the beam, its cross-sectional shape, the length of the beam, and the support conditions at each end.

## What are the common methods for calculating beam deflection?

The most commonly used methods for calculating beam deflection are the double integration method, the moment area method, and the conjugate beam method. These methods use mathematical equations and principles to determine the deflection of a beam under different loading conditions.

## What is the unit of measurement for beam deflection?

The unit of measurement for beam deflection is typically in millimeters (mm) or inches (in). However, it can also be expressed in other units such as meters (m) or feet (ft), depending on the size and scale of the structure being analyzed.