When we talk about loads, we’re referring to the combined impact of external forces on an object. These forces come in various forms, and understanding their classification is crucial for engineering and design purposes.
Loads can be grouped into different categories based on their nature and characteristics. Here are two primary classifications:
Another way to categorize loads is based on their specific characteristics:
Understanding how the load is applied is equally important. Loads can be either concentrated at a point or distributed over a certain area.
A point load, also known as a concentrated load, is considered to act at a single point. In practical scenarios, this load needs to be distributed over a small area. Achieving knife-edge contacts at such a small scale is often impractical and undesirable.
On the other hand, a distributed load is spread over the length of the beam. If this spread is uniform, meaning it occurs at a consistent rate (e.g., w kN or N/metre run), it is termed a uniformly distributed load (abbreviated as u.d.l.). If the spread is not uniform, we call it a non-uniformly distributed load. This category includes triangular and trapezoidal distributed loads.
In summary, understanding the classification of loads and how they are applied—whether as point loads or distributed loads—provides a foundation for effective engineering and design, ensuring structures can withstand the forces they encounter.