Dynamic Amplification Factor

Definition

The Dynamic Amplification Factor (DAF), also sometimes called the Dynamic Load Factor (DLF) is defined as the ratio of the displacement obtained when a load is applied dynamically compared to the displacement obtained when the load is applied statically. The DAF is a function of the shape of the pulse, the duration of the pulse td and the natural period of the structure T. The following graphs give the value of DAFs for a range of pressure pulses.

Triangular Pressure Pulses

Shock Triangular Pressure Pulses (tr / td = 0.0)

In a shock triangular pulse the rise time tr is 0, i.e. the peak pressure is reached instantaneously.
DAF (+ve) Shock Triangular Pulse DAF (-ve) Shock Triangular Pulse

Isosceles Triangular Pressure Pulse (tr / td = 0.5)

In an isosceles triangular pulse the rise time tr is half of the pulse duration td.
DAF (+ve) Isosceled Triangular Pulse DAF (-ve) Isosceled Triangular Pulse

Rectangular Pressure Pulses

DAF (+ve) Rectangular Pulse DAF (-ve) Rectangular Pulse