Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


17330.pdf (5.83 MB)

ETD Abstract Container

Abstract Header

A Computational Study of Dynamic Brittle Fracture Using the Phase-Field Method

Deogekar, Sai Sharad
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439455086

Abstract Details

2015, MS, University of Cincinnati, Engineering and Applied Science: Mechanical Engineering.
This thesis describes the use of the phase-field method to model and simulate dynamic crack propagation in brittle materials. In this method, the discrete crack is modeled as a smeared or diffuse interface using a continuous phase-field. In the solid phase, the phase-field takes on the value one, while it is zero in the crack phase. A length parameter is introduced into the problem to model the thickness of the transition region between the solid and crack phases. To capture the weakening of the material in the crack phase, the constitutive response is modified to depend on the local value of the phase-field. The evolution of the phase-field is described by a partial differential equation derived using variational arguments. This leads to a coupled system of two partial differential equations for the displacement field and the phase-field, which is solved using a staggered nonlinear finite element method. The phase-field approach does not require numerical tracking of the discontinuities in a domain and is able to capture complex crack behavior such as branching and merging/interaction of cracks without any ad hoc criteria for crack nucleation. In this work, we implement the phase-field formulation for two-dimensional domains under plane strain conditions. We use this implementation to study various cases of dynamic brittle fracture, namely the interaction between two cracks and the crack propagation in composite materials. We simulate the interaction between two cracks, under both static and dynamic loading, for various distances between the crack tips. The results from our dynamic simulations indicate that, unlike crack interaction under quasi-static or fatigue loading, the presence of another crack does not accelerate crack propagation when dynamic loads are applied. However, some similarities in the crack topologies are observed between the quasi-static and dynamic loading. We also use this method to model dynamic crack propagation in laminated and fibrous composites successfully. We observe that the crack branches and the crack path changes so as to evade the tougher material
Kumar Vemaganti, Ph.D. (Committee Chair)
Woo Kyun Kim, Ph.D. (Committee Member)
Yijun Liu, Ph.D. (Committee Member)
108 p.
Mechanics
Phase-field method; Dynamic brittle fracture; Crack interaction; Crack propagation in composites; Multiple cracks

Recommended Citations

Citations

  • Deogekar, S. S. (2015). A Computational Study of Dynamic Brittle Fracture Using the Phase-Field Method [Master's thesis, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439455086

    APA Style (7th edition)

  • Deogekar, Sai. A Computational Study of Dynamic Brittle Fracture Using the Phase-Field Method. 2015. University of Cincinnati, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439455086.

    MLA Style (8th edition)

  • Deogekar, Sai. "A Computational Study of Dynamic Brittle Fracture Using the Phase-Field Method." Master's thesis, University of Cincinnati, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439455086

    Chicago Manual of Style (17th edition)

ucin1439455086
740
© 2015, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.