timingloads

Timing loads are loads whose magnitude changes over time and are specified by a load-time history. They are used in engineering to evaluate how systems respond to transient or cyclic forces, as opposed to static loads.

Timing loads are characterized by their time function, duration, repetition, and timing relative to other events. Common time functions include step, ramp, sinusoidal, exponential decay, and random or recorded time histories. Important parameters include rise time, peak value, dwell time, and frequency content.

They can be measured directly from sensors during real-world events or generated synthetically from models, simulations, or standards.

In civil engineering, seismic and wind gust loads are often treated as timing loads; in automotive and aerospace, engine torque, braking, gusts, and maneuver loads are applied as time histories; in manufacturing, impact and start-up transients.

Time-history analysis, dynamic finite element analysis, spectral methods, and modal analysis with response spectrum are used to evaluate system response to timing loads. Designers may use quasi-static methods with dynamic amplification factors when appropriate, and must account for damping, inertia, stiffness, and boundary conditions.

See also: time-history load, dynamic load, ramp load, step load, fatigue analysis, response spectrum.