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CREATED:20261009T231229Z
DESCRIPTION:Traditional structural design focuses on preventing fracture, limiting applicability in systems that require controlled, predictable failure. This dissertation developed a dual-physics optimization framework that couples finite element analysis (FEA) with peridynamic fracture simulation to design structures where engineered failure is a primary objective.\n\nThe framework linked DOLFINx-based transient FEA for impact stress evaluation with Peridigm peridynamic fracture modeling through a fracture-aware thickness cap that prevents stress-driven thickening from compromising fracture performance. The parameterized thin shell structure, with independent thickness and fracture zone definitions per sectoral region, enabled automated mesh generation, multi-orientation drop simulation, and crack-line connectivity evaluation within a closed optimization loop. Six optimization methods were compared across band-count and initial-thickness sensitivity studies.\n\nThe breakaway weight shell for Hawaiian pelagic longline fisheries served as the validation application. Flyback events, in which a failed fishing line accelerates the weighted swivel at high speed, pose serious injury risks to crew; the breakaway shell must survive normal handling while fracturing reliably upon flyback impact. Experimental testing established the loading environment, and peridynamic simulations verified that fracture propagated along designed failure planes.\n\nThe optimization achieved stress feasibility while maintaining fracture performance, with methods converging to qualitatively viable thickness profiles. The peridynamic fracture simulations confirmed that geometric selectivity alone directed crack propagation along designed failure planes without requiring differentiated material properties. The fully automated framework, from parameterized geometry through fracture evaluation, demonstrated that treating fracture as a design variable within a dual-physics loop is a viable and generalizable approach for frangible structural systems.
DTEND;TZID=Pacific/Honolulu:20260304T093000Z
DTSTAMP:20261009T231229Z
DTSTART;TZID=Pacific/Honolulu:20260303T203000Z
LAST-MODIFIED:20261009T231229Z
LOCATION:Bilger Hall 152
PRIORITY:5
SEQUENCE:0
SUMMARY;LANGUAGE=en-us:ME PhD Thesis Defense- Matthew Nakamura
TRANSP:OPAQUE
UID:179162354945159web-support-l@lists.hawaii.edu
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