Semester
Fall
Date of Graduation
2018
Document Type
Dissertation
Degree Type
PhD
College
Statler College of Engineering and Mineral Resources
Department
Mechanical and Aerospace Engineering
Committee Chair
Ever J. Barbero
Committee Co-Chair
Bruce S. Kang
Committee Member
Bruce S. Kang
Committee Member
Eduardo M. Sosa
Committee Member
Victor H. Mucino
Committee Member
Adi Adumitroaie
Abstract
Carbon fiber reinforced plastics (CFRP) are potential materials for many aerospace and aeronautical applications due to their high specif strength/weight and a low coeffcient of thermal expansion (CTE) resulting in a high long-term stability. Among candidate structures, the re-entry reusable launch vehicles (RLV), the fuel oxidant storage and transportation at cryogenic temperature, space satellites, and aircraft structure (frame, wings, etc...) can be highlighted. However, CFRP are prone to internal damage as a result of high residual stresses and thermal fatigue loading. In this study, micro-cracking damage evolution in laminated composites subjected to monotonic cooling and thermal cyclic loads is developed through a theoretical model. Since matrix-damage predictions requires precise knowledge of the temperature-dependent properties, a detailed methodology to calculate the thermomechanical properties for both matrix and fibers of interest is included. Damage initiation and evolution is studied firstly under quasi-static cooling. The temperature dependence of the critical energy release rate (ERR) is also analyzed. Thermal fatigue of laminated composites is assessed based on low-cycle fatigue tests and the damage mechanisms involved are studied. A Master Paris's law is developed to predict matrix fatigue resistance as function of number of cycles regardless of layup and thermal ratio for both, low and high-cycle tests. Due to physical barriers that implies to perform a complete high-cycle thermal fatigue test, a methodology to simulate a thermal fatigue test using equivalent mechanical cyclic loads is developed to use the former as surrogate from later.
Recommended Citation
Cabrera Barbero, Javier, "Thermal-Fatigue and Thermo-Mechanical Equivalence for Transverse Cracking Evolution in Laminated Composites" (2018). Graduate Theses, Dissertations, and Problem Reports. 3715.
https://researchrepository.wvu.edu/etd/3715
Included in
Computer-Aided Engineering and Design Commons, Engineering Mechanics Commons, Mechanics of Materials Commons, Polymer and Organic Materials Commons, Space Vehicles Commons, Structures and Materials Commons