Date of Award

2020-01-01

Degree Name

Master of Science

Department

Mechanical Engineering

Advisor(s)

Alejandra G. Castellanos

Abstract

The need of lightweight launch vehicles that will reduce the cost and make flights more frequent into orbit has called for an increase of composite materials in the aerospace industry. Composite material’s low thermal conductivity, high resistance to fatigue, and most importantly, low-weight can greatly reduce the cost of launch operations by decreasing the overall weight of the vehicle. Weight and cost savings are critical because any amount of weight that is saved can be directly applied as an additional amount of payload capability. The tanks on space vehicles are pressurized vessels that store fuel at cryogenic temperatures and have generally been either entirely manufactured or lined with metals. In most cases the tanks are the main structure of the vehicle which consequently can become the heaviest component. These vehicle tanks are exposed to extremely cold temperatures and gravitational loads that weaken the material and could potentially cause a fuel leak. Carbon fiber polymer matrix (CFRP) composite materials are a promising option for replacing conventionally used metal in cryogenic tank structures. Therefore, the understanding of composite materials under cryogenic exposure is essential for the next generation of spacecraft propellant tanks. The flexural behavior of plain-woven carbon fiber and plain-woven Kevlar fiber with Epon 828/ Epikure 3015 curing agent is studied as a potential commercially available material system for application in cryogenic tanks. Samples were exposed to cryogenic temperatures at one surface and to room temperature at the other surface to mimic a realistic environment that the tanks will be exposed to. Carbon and Kevlar fiber with epon/epikure material system for pressure vessels are an ideal material selection for cryogenic tank applications. Most current analysis only concentrate on testing materials entirely under cryogenic temperatures, or room temperature. Many fail to consider the small, but impactful temperature gradient caused by the low temperature propellant and ambient temperature on either side of the tank walls.

Language

en

Provenance

Received from ProQuest

File Size

68 pages

File Format

application/pdf

Rights Holder

Itzel Adriana Torres

Available for download on Sunday, June 19, 2022

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