What type of load is characterized by a sudden impact on a structure?

A dynamic load is characterized by its nature of being time-varying and can involve sudden changes in force or motion applied to a structure. This could arise from forces like wind gusts, earthquakes, or, notably, impacts resulting from objects falling or vehicles colliding with a structure. These loads create a fluctuation in force that differs from static loads, which are constant or change very slowly over time.

In contrast, static loads are applied to a structure at rest and do not change over time. Live loads typically refer to transient forces like occupant loads or furniture in a building, but these are not sudden impacts. Dead loads refer to the permanent static weights of the structure itself, including materials and fixtures. Therefore, dynamic loads are the only type that encompasses quick, impactful forces acting on a structure.