Date of Award

2023-12-01

Degree Name

Doctor of Philosophy

Department

Engineering

Advisor(s)

Yirong Lin

Second Advisor

Eric MacDonald

Abstract

Composite materials are made by combining two or more materials, such as fibers and resins to create a material system that has improved mechanical and physical properties compared to its individual components. The use of 3D printing technology in composite manufacturing allows for the creation of complex and custom shapes with precise control over the placement of the materials. This makes it possible to create composite parts with enhanced performance characteristics and reduced weight. The work presented in this dissertation lies in the design and development of highly flexible impact propagation sensor through material extrusion 3D printing technique. By using a multi-material 3D printing method, barium titanate (BTO) piezoelectric sensor was printed by blending with Polydimethylsiloxane (PDMS) as a sensing part, while PDMS with multi-walled carbon nanotubes (MWCNT) has been mixed to print electrode part to ensure excellent bonding between sensing and electrode materials. The designed multi node disc type flexible sensor was fabricated to determine the particle wave velocity of any structural material. Impact load generated piezoelectric output voltage was collected from the nodes at different locations. Another ongoing research in the field of 3D printing for harsh environment applications is additive manufacturing of thermosetting polymer-based composites which are extensively applied in demanding conditions, particularly in high-temperature settings, owing to their outstanding thermal and mechanical characteristics. The first-ever establishment of the 3D printability and curing schedule for composites based on bismaleimide (BMI) and epoxy based thermoset polymer were presented as major contribution. The curing mechanism of these composites was extensively analyzed, and their thermal and mechanical stability was evaluated. The results demonstrate that increasing the curing time and temperature significantly improves the glass transition temperature of the printed parts. The sustainability of the 3D printed cured bismaleimide (BMI) thermoset composite at temperatures up to 298°C was also confirmed. Epoxy based thermosetting material is another composite that can sustain at high temperature environment and 3D printing of this material has been demonstrated in this dissertation. SLS printing of different lattice structures and their mechanical stability at high temperature environments have been presented here.

Language

en

Provenance

Recieved from ProQuest

File Size

109 p.

File Format

application/pdf

Rights Holder

Md Sahid Hassan

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