Thesis
Structural integrity of countersunk-hole joints in aluminum-steel and GFRP-steel stack-ups
Washington State University
Master of Science (MS), Washington State University
2015
Handle:
https://hdl.handle.net/2376/101331
Abstract
The basis of this thesis study was to explore the capability of the extended finite element method to correctly predict crack propagation and stress intensity factors for high-cycle fatigue for various length corner cracks on a hole that contained compressive residual stresses. The extended finite element method, referred to as XFEM, is a relatively new method for finite element software packages, such as Abaqus, that allows the placement of a dislocation, or crack, on a 2D or 3D part without the need to conform to the mesh. Although there have been previous numerical and simulation studies for instances of a corner crack on a hole with residual stresses, none have yet tested this case using XFEM. Certain XFEM mesh sensitivities were discovered during this study. There are cases discussed in which an XFEM crack will fail to generate depending on the crack location in relation to the mesh and direction of applied stress. Additionally, the result values will vary depending on the distance of the XFEM crack tip location in relation to the next mesh element. Hole expansion was modeled for 2D and 3D. For both cases, the deformed part was extracted from the result file and the residual stresses were imported and added to the part in the initial step of the crack analysis. For 2D, a 1 mm initial crack was placed on both sides of the hole. The 2D XFEM crack model was successful in representing a delayed onset in crack propagation due to the compressive residual stresses reducing the effective applied load. For 3D, six different crack sizes, based off a previous high-cycle fatigue study, were modeled for a hole with and without residual stresses. Stress intensity factor values were extracted and the data agreed well with the high-cycle fatigue data.
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Details
- Title
- Structural integrity of countersunk-hole joints in aluminum-steel and GFRP-steel stack-ups
- Creators
- Thomas John Matson
- Contributors
- Dave Kim (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525369301842
- Language
- English
- Resource Type
- Thesis