3.6. Velocity and Displacement History

imcalculator.get_velocity_displacement_history()

Computes velocity and displacement time histories with baseline drift correction.

A zero-phase fourth-order Butterworth high-pass filter (corner frequency 0.1 Hz) is applied to the acceleration record before integration. Velocity and displacement are obtained by trapezoidal integration of the filtered acceleration, with linear detrending applied after each integration step to remove residual drift.

Parameters:

None

Returns:

• vel (numpy.ndarray) – Velocity time history (m/s).

• disp (numpy.ndarray) – Displacement time history (m).

Notes

The zero-phase filter (sosfiltfilt) applies the Butterworth filter in both the forward and backward directions, eliminating phase distortion.