What is a distributed load?
Also called linear load, this type acts uniformly on a structural element.
Its effects on structures are less than those of point loads, so they are not usually analyzed. However, the concept of distributed load is used for analyzing other types of loads, such as live load.
What unit of measurement is used to express distributed load?
Distributed loads require knowing the load weight, as well as the surface dimensions over which it is distributed, so its units of measurement combine these two elements: weight/surface. For example, it can be measured in kilograms/ml, pounds/ft, or tons/ml.
What types of distributed loads are there?
Distributed loads are classified according to shape; this is relevant to being able to calculate the actual load and its effects on the structure. For calculation purposes, a distributed load may be:
- Combined (combines rectangular and triangular sections).
How is distributed load transformed to point load and for what purpose?
When there is a distributed load, it must be theoretically transformed into a point load to determine the total magnitude of the force, and thus find the reactions of the supports for the loads on the structural analysis.
The parts of the equation used to pass a distributed load to a point load are:
W: distributed load
F: point load force
L: distance traveled by the distributed load
Depending on the shape of the load, the force calculation will be made as follows:
- Rectangular load: calculated as if the point load were located at the midpoint of the length of the structure, and the formula used is F=W⋅L
- Triangular load: calculated as if the point load were located at one-third of the distance, leaving greater distance on the lower side of the triangle and less on the higher one; the formula used is F=W⋅L2
- Combined load: making the calculation requires dividing the load up by zones and calculating each of them as rectangular or triangular loads, as appropriate.
What are the most common distributed loads?
- Ceiling tiles.
- Accidental and environmental loads, such as snow.