Honors Theses

Date of Award

5-9-2020

Document Type

Undergraduate Thesis

Department

Mechanical Engineering

First Advisor

Damian Stoddard

Second Advisor

A. M. Rajendran

Third Advisor

Tejas Pandya

Relational Format

Dissertation/Thesis

Abstract

Dynamic characterization of materials has become increasingly common, as it is important to understand how materials behave under sudden loads. Understanding these properties can aid in material selection for novel designs. DuroProtect, a fiber-reinforced ballistics composite developed by Rӧchling, was tested for its dynamic properties at high strain-rates. The Split Hopkinson Pressure Bar (SHPB) test was used to obtain dynamic properties at high strain-rates under compressive loading conditions. Tests were initially conducted to validate force equilibriums for each sample. The data measured from the strain gages mounted on the incident and transmission bars and the elastic wave propagation theories yields the stress-strain curves. DuroProtect Level 1 and Level 2 samples were tested at strain rate ranges between ~800/s to ~1900/s and ~1300/s to ~2000/s, respectively. Differences between Level 1 and Level 2 samples were attributed by the number of fiber layers and thickness of the manufactured panels. Results showed no conclusive evidence for strain-rate sensitivity within the strain-rates tested for Level 1 or Level 2, as initially hypothesized. A comparison study between the two thicknesses revealed that Level 1 had the greatest ultimate compressive strength at a range of 547-595 MPa. Level 2, however, had the greatest specific energy of 25-44 kJ. The Level 1 and Level 2 stress-strain measurements for the DuroProtect composite were consistent with the properties expected for fiber-reinforced composites, although there is no conclusive evidence of strain-rate sensitive behaviors within the tested ranges of strain-rates.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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