07/22/2021
By Sokny Long

The Francis College of Engineering, Department of Mechanical Engineering, invites you to attend a Master’s thesis defense by Joseph McDonald on "Characterization and Optimization of Wind Turbine Repair Procedures."

MSE Candidate: Joseph McDonald
Defense Date: Monday, Aug. 2, 2021
Time: 1 to 2 p.m. EST
Location: This will be a virtual defense via Zoom. Those interested in attending should contact joseph_mcdonald@student.uml.edu and committee advisor, marianna_maiaru@uml.edu, at least 24 hours prior to the defense to request access to the meeting.

Committee Chair (Advisor): Marianna Maiaru. Assistant Professor, Mechanical Engineering, UMass Lowell

Committee Members:

  • Christopher Hansen, Associate Professor, Mechanical Engineering, UMass Lowell
  • Scott Stapleton, Assistant Professor, Mechanical Engineering, UMass Lowell

Brief Abstract:
Wind energy has replaced hydroelectric power as the largest source of renewable energy production in the US, with a record 93 gigawatts installed worldwide in 2020. It provides an effective, clean way to help meet growing global energy demands. These turbines, however, are inevitably exposed to environmental damage such as erosion and lightning strikes. Current repair procedures consist of an on-site team evaluating the damage and using standardized cure cycles to apply a repair patch. During this repair process the existing blade and the repair components may be exposed to elevated temperature and humidity that impact both the curing process and mechanical performance of repair patches. To characterize these hygrothermal effects, both the uncured, unmixed epoxy resin system and samples of fully cured epoxy resin-glass fiber laminates were exposed to environmental and submersion moisture testing respectively. Uncured samples had the cure kinetics for the Prout-Tompkins model determined through DSC testing. Cured samples were subjected to long term moisture absorption testing and used to create a predictive model that can be used to condition specimens quickly to a set moisture content. To further help optimize repair procedures cure kinetics are used in a finite element curing model. The model aims to create a prediction of temperature development as a function of cure kinetics, repair geometry and temperature profile. To validate laminates cured virtually, recreations were manufactured under lab conditions. Temperature data collected in these experimental laminates was compared to the results generated by the finite element model. In performing these various tests a further understanding of the relationship between environmental factors, repair geometry, and cure analysis was developed.

All interested students and faculty members are invited to attend the online defense via remote access.