<p> Methods for modeling structural failure with applications for fluid structure interaction (FSI) are developed in this work. Fracture as structural failure is modeled in this work by both the extended finite element method (XFEM) and element deletion. Both of these methods are used in simulations coupled with fluids modeled by computational fluid dynamics (CFD). The methods presented here allow the fluid to pass through the fractured areas of the structure without any prior knowledge of where fracture will occur. Fracture modeled by XFEM is compared to an experimental result as well as a test problem for two phase coupling. The element deletion results are compared with an XFEM test problem, showing the differences and similarities between the two methods. </p><p> A new method for modeling fracture is also proposed in this work. The new method combines XFEM and element deletion to provide a robust implementation of fracture modeling. This method integrates well into legacy codes that currently have element deletion functionality. The implementation allows for application by a wide variety of users that are familiar with element deletion in current analysis tools. The combined method can also be used in conjunction with the work done on fracture coupled with fluids, discussed in this work. </p><p> Structural failure via buckling is also examined in an FSI framework. A new algorithm is produced to allow for structural subcycling during the collapse of a pipe subjected to a hydrostatic load. The responses of both the structure and the fluid are compared to a non-subcycling case to determine the accuracy of the new algorithm. </p><p> Overall this work looks at multiple forms of structural failure induced by fluids modeled by CFD. The work extends what is currently possible in FSI simulations.</p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:3605735 |
| Date | 31 January 2014 |
| Creators | Lea, Patrick D. |
| Publisher | Northwestern University |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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