Date of Award

Fall 2020

Document Type

Open Access Dissertation

Department

Mechanical Engineering

First Advisor

Austin Downey

Abstract

Estimating the state of structures that experience high-rate dynamics requires real-time model updating capabilities. In this work, high-rate dynamic events are characterized by 1) large uncertainties in the external loads, 2) high levels of non-stationarities and heavy disturbances, and 3) unmodeled dynamics generated from changes in system configurations. To achieve real-time model updating, an algorithm must circumvent any pre-calculations and be able to update the structure’s state on the timescale of 2 ms or less. This can be accomplished in one of two ways: either by creating a simplified model of a complex structure or by simplifying the calculations needed to determine the state of a complex structure. This work presents a methodology that updates a surrogate model of an experimental testbed experiencing varying dynamics by utilizing the local eigenvalue modification process (LEMP) to numerically simplify solving equations of state. The structure’s state is continuously updated by adjusting the associated model through online modal analysis where its future states are estimated using a Bayesian search algorithm to compare the measured signals with selected modal models. New modal models are built based on the enhanced estimate of the structure's state and used for subsequent state estimations.

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