03/13/2025
By Danielle Fretwell

The Francis College of Engineering, Department of Mechanical Engineering, invites you to attend a Doctoral Dissertation defense by George Barlow on "Investigating The Inclusion of Variation When Modeling Dry Fiber Compaction Using Finite Element Modeling."

Candidate Name: George Barlow
Defense Date: Monday, March 24, 2025
Time: 2 - 4 p.m.
Location: Southwick 240

Committee:
Advisor: Scott Stapleton, Associate Professor, Mechanical and Industrial Engineering, UMass Lowell

Committee Members*
1. Murat Inalpolat, Associate Professor, Mechanical and Industrial Engineering, UMass Lowell
2. Lei Chen, Associate Professor, Mechanical and Industrial Engineering, UMass Lowell
3. David Mollenhauer , Principal Materials Engineer, Air Force Research Laboratory

Abstract:
Computational models, including the finite element method (FEM), have become an important part of the structural design process for various applications. Finite element models can be used to replicate experimental results using matching geometry. The models can also include variations within their geometry or configuration to study how these variations impact the results. This work will examine the inclusion of variations in the geometry within the use of finite element models of the compaction of dry fiber textiles. These models will look at the effect on compaction from the introduction of entanglement with the fiber bundle. This will include the introduction of a method of entanglement generation through the selective swapping of fiber paths through the length of the bundle. Previous efforts have found that modeling the compaction of fiber bundles without the inclusion of entanglement leads to increased fiber volume fraction for compaction to same pressure as compared to experiments. This entanglement approach is then investigated using both the Air Force Research Lab’s Virtual Textile Morphology Suite (VTMS) and commercial finite element solvers such as LS DYNA. This work continues with the introduction of volumetric crossover density as a metric to identify the amount of movement and entanglement within a fiber bundle and investigates the relationship between volumetric crossover rate and the bundle compacted volume fraction. The volumetric crossover density will be investigated for both bundles compacted using finite element models and analyzing scans from experimentally manufactured composites. The variation from entanglement and movement of fibers modeled using the finite element method will be investigated and characterized using the volumetric crossover density.