PhD Thesis Proposal 

Qirui He

(Faculty advisor: Professor Keegan Moore )

"Reduced-Order Modeling Framework for Bolted Joint Loosening in Harmonic Oscillator Systems"

Tuesday, October 27

10:00 a.m. - 12:00 p.m.

MK 317

Abstract: 

Bolted joints are one of the most prevalent types of mechanical joints used in nearly every industry, and structures generally contain numerous bolted joints. Consequently, loosening of a single bolt could result in catastrophic failure. Despite this issue, loosening of bolts in real structures cannot be predicted because current approaches are too analytically or computationally expensive.
This work aims to develop a physics-based reduced-order modeling framework to predict loosening of bolted joints. The basis of the model is an assertion that bolt tension is a dynamic degree-of-freedom that governs the dynamic properties of the joint. The model was developed and optimized through three-staged experiments on a pair of harmonic oscillators connected by a single bolt through a pair of lap joints under transverse shock excitation. This model is subsequently tested for various system configurations under different loading conditions and refined to capture the nonlinear dynamics of the structure at low preload. This work will deliver a reduced-order modeling framework that can effectively predict tension loss in engineering structures and improve the understanding of the nonlinear bolted-joint dynamics.

Committee:
Dr. Keegan Moore (advisor), School of Aerospace Engineering
Dr. Cristina Riso, School of Aerospace Engineering
Dr. Yang Wang, School of Civil and Environmental Engineering