What type of load is applied intermittently and can change often?

The type of load that is applied intermittently and can change often is known as a dynamic load. Dynamic loads are characterized by being variable in magnitude and direction, which means they can fluctuate during operation. Examples of dynamic loads include moving vehicles on a bridge, wind acting on structures, and forces applied during equipment operations.

This is in contrast to static loads, which remain constant over time and do not change, and are typically found in structures under a steady weight or pressure. Environmental loads can include factors such as snow, wind, or temperature changes, but these are often considered under specific conditions and may not apply intermittently. Permanent loads refer to constant loads that are always present, such as the weight of the building materials themselves. Understanding the nature of dynamic loads is crucial for designing structures that can withstand varying forces without failing.