07/23/2024
By Danielle Fretwell

The Francis College of Engineering, Department of Mechanical Engineering, invites you to attend a Master's Thesis defense by Kalima Bukenya on "Characterization and Modeling of Thermosets for Textiles."

Candidate Name: Kalima Bukenya
Degree: Master’s
Defense Date: Monday, Aug. 5, 2024
Time: 11 a.m. to 1 p.m.
Location: Via Zoom. All interested students and faculty members should contact the advisor, christopher_hansen@uml.edu, or the student for Zoom link. 

Committee:

  • Advisor: Christopher Hansen, Ph.D., Department Chair and Professor, Mechanical & Industrial Engineering, UMass Lowell
  • Co-Advisor: Marianna Maiaru, Ph.D., Associate Professor, Civil Engineering and Engineering Mechanics (CEEM), Columbia University
  • Alessandro Sabato, Ph.D., Assistant Professor, Mechanical & Industrial Engineering, UMass Lowell
  • Juan Pablo Trelles, Ph.D., Professor, Mechanical & Industrial Engineering, UMass Lowell
  • Evan J. Pineda, Ph.D., Aerospace Research Engineer, Materials and Structures Division, NASA Glenn Research Center

Brief Abstract:
This thesis presents a comprehensive study on the curing behavior and its impact on residual stresses in woven polymer matrix composites (PMCs) through experimental and computational approaches. Three-dimensional digital image correlation (3D-DIC) is used to measure the volumetric chemical shrinkage of EPON 862 resin during curing, providing novel insights into thermoset shrinkage. Differential scanning calorimetry (DSC) correlates these measurements with the degree of cure. Virtual curing simulations of plain weave textile architectures are conducted using TexGen and Abaqus, incorporating user-written subroutines to model various curing parameters. The study compares different boundary conditions and finds that an Abaqus linear elastic thermal cooldown overestimates final stresses, with chemical shrinkage contributing significantly to residual stress. Further analysis of 2D woven PMCs highlights the sensitivity of end stress states to boundary condition assumptions. The thesis also addresses processing-induced defects in 3D woven composites, revealing high stress concentrations that align with X-Ray computed tomography (X-Ray-CT) data. This research provides valuable insights into curing-induced residual stresses in woven PMCs, offering a robust framework for accurate process modeling to optimize manufacturing processes and enhance composite material performance in aerospace and other applications.