logarithmic_decrement Function

public pure elemental function logarithmic_decrement(x1, x2, n) result(rst)

Computes the logarithmic decrement given the value of two successive peaks in the time history of the free vibratory response of the system. The logarithmic decrement is calculated as follows.

$$\delta = \frac{1}{N} \ln \left( \frac{x(t)}{x(t + N T)} \right) = \frac{1}{N} \ln \left( \frac{x_1}{x_2} \right)$$

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=real64),	intent(in)			::	x1	The amplitude of the first peak.
real(kind=real64),	intent(in)			::	x2	The amplitude of the second peak that occurs N periods after the first.
integer(kind=int32),	intent(in)			::	n	The number of periods of oscillation seperating the two peaks.

Return Value real(kind=real64)

The logarithmic decrement $\delta$.

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