Doctoral Dissertations

Keywords and Phrases

Aging of composites; Finite element; High-temperature polymer composites; Multi-physics modeling; Multi-scale modeling; Thermo-oxidation

Abstract

"High-temperature polymer matrix composites (HTPMCs) are susceptible to thermo-oxidation, which accelerates the composites' degradation and reduces the service life. Mechanical properties of HTPMCs deteriorate due to coupled thermo-oxidation and cross-linking mechanisms. Bismaleimides (BMIs) are commonly used high-temperature resins for aerospace applications. This work presents the viability of using experimental weight loss to model the spatial distribution of oxidation when the oxidized polymer matrix is not discernible. Three tasks are introduced: (1) Anisotropic oxidation prediction using optimized weight loss behavior of bismaleimide composites, (2) A multi-scale modeling of thermo-oxidative effects on the flexural behavior of cross-ply bismaleimide composites, and (3) Thermo-oxidative induced damage in polymer composites: microstructure image-based multi-scale modeling and experimental validation. Task 1 deals with simulating the weight loss and oxidized layer evolution in unidirectional BMI composites exposed to a service temperature in the operating range, 176.67 °C (350 °F) and 200 °C (392 °F). In task 2, microstructural changes of the cross-ply BMIs composites were characterized using microscopy. A multiscale approach for modeling flexural modulus degradation was proposed. In Task 3, a multi-scale modeling approach is presented to simulate and validate thermo-oxidation shrinkage and cracking damage. The micro-scale shrinkage deformation and cracking damage are simulated and validated using 2D and 3D simulations. The meso-scale geometrical domain and the micro-scale geometry and mesh are developed using the object oriented finite element (OOF). The macro-scale shrinkage and weight loss are measured using unidirectional coupons and used to build the macro-shrinkage model"--Abstract, page iv.

Advisor(s)

Chandrashekhara, K.

Committee Member(s)

Dharani, Lokeswarappa R.
Isaac, Kakkattukuzhy M.
Okafor, A. Chukwujekwu (Anthony Chukwujekwu)
Samaranayake, V. A.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2018

Journal article titles appearing in thesis/dissertation

  • Anisotropic oxidation prediction using optimized weight loss behavior of bismaleimide composites
  • Multi-scale modeling of thermo-oxidation effects on the flexural behavior of cross-ply bismaleimide composites
  • Thermo-oxidative induced damage in polymer composites: Microstructure image-based multi-scale modeling and experimental validation

Pagination

xii, 120 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2018 Rafid Muhammad Hussein, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11485

Electronic OCLC #

1104294922

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