A Novel Approach to the Integration for Generating Consistent Ground Acceleration, Velocity and Displacement Time Histories

The velocity and the displacement time history obtained by directly integrating the acceleration time history will drift unrealistically because of the over-determinacy of the integration constants. Applying baseline corrections to resolve drift disturbs the frequency content and renders the corrected processes mutually inconsistent. In this study, eigenfunctions of sixth-order eigenvalue problem are introduced as basis functions for decomposing recorded ground motion time history. Taking advantage of the eigenfunctions and their first two order of differentiations are drift-free and consistent, the decomposed and reconstructed acceleration, velocity, and displacement time histories can be drift-free and mutually consistent without direct integration and baseline correction. Two earthquake ground motions are presented as examples, which show that the decomposed acceleration, velocity, and displacement time histories are drift-free, mutually consistent, and almost the same as the seed motion. The new approach can replace integral in the generation of velocity and displacement time histories.