Beams have to be strong and stable, and two types of loads really matter when it comes to how they hold up over time.

1. Temporary Loads:

These are forces that don’t stick around for long. Think of them like live loads—like people walking on a floor or furniture on a beam. They can make the beam bend or flex a little, but once the load is gone, the beam goes back to normal.

2. Permanent Loads:

These loads stick around. They are like dead loads, which could be the weight of the beam itself or anything that is permanently placed on it, like a roof. Since these loads are always there, they create lasting stress on the beam, which can wear the material down over time.

To keep beams safe and strong, we need to make sure they can handle both temporary and permanent loads.

Engineers use the idea of equilibrium to balance everything out. This means they must design beams to handle both kinds of loads together.

To figure out how much stress a beam can handle when it bends, they use a simple formula:
$\sigma = \frac{M}{S}$

In this formula, $M$ stands for the moment (or how much the beam is bending), and $S$ represents the section modulus (which measures the beam’s strength).

Understanding these loads and how they affect beams is super important. It helps engineers build strong and safe structures that will last!