Master of Science
Dr. Dazhi Jiang
Fabric is important for the interpretation of tectonic evolutions. In the process of extrapolating small-scale fabric to tectonics, modeling frameworks are needed. Neither the early kinematic models nor the contemporary computational geodynamics are able to capture the complexities of the fabric development in natural deformation systems. Eshelby proposed a formalism in micro-mechanics, and it is now well understood that this formalism works well for the linear viscous deformations. However, given that most of the natural rocks are power-law materials, the Eshelby Formalism cannot be directly applied to geological problems. This problem was largely solved when Lebensohn and Tom (1993, Acta Metallurgica et Materialia, vol 41, 2611-2624) incorporated a linearization scheme with Eshelby Formalism, known as the Tangent Linearization. The purpose of this project is to validate the applicability of the Eshelby Formalism with Tangent Linearization (EFTL) or with Secant Linearization (EFSL) to power-law material deformations. Two types of simulations are proceeded, one is based on EFTL / EFSL, while the other one based on 2D finite difference geodynamic method. Comparisons of the two simulations show that even in the most general situation of power-law material deformations, EFSL has major differences with the simulated power-law behavior while EFTL has only an approximately 10% deviation. Through this project, EFTL is validated to be a new, sufficient framework for fabric modeling, which marks a new era of fabric interpretation both in theoretical simulations and in field work practice.
Zhong, Zhenyu, "Applicability of the Eshelby Formalism to Viscous Power-Law Materials: A Numerical Validation" (2012). University of Western Ontario - Electronic Thesis and Dissertation Repository. Paper 541.