Ultrasonic stress measurement for evaluating the adequacy of gusset plates
Abstract
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] A significant challenge in determining the safety margin for gusset plates is determining the level of stresses carried in the plate. Present technologies are unable to evaluate the dead, live and residual stresses maintained in gusset plates. The goal of the research presented in this thesis is to improve the safety of highway bridges by developing and testing an ultrasonic stress measurement methodology for determining actual stress in steel gusset plates, evaluating the accuracy and precision of the measurements, and assess if the methodology has sufficient accuracy and precision to be a useful tool in the safety analysis of gusset plates. This research utilizes the acoustoelastic effect to evaluate actual stress levels by assessing the acoustic birefringence in a steel material. The birefringence measurement evaluates normalized variations of polarized shear waves propagating through the plate thickness, which vary proportionally as a function of stress. This thesis discusses exploratory testing to evaluate the potential of the approach as a tool for the condition assessment of gusset plates.
Degree
M.S.
Thesis Department
Rights
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