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You searched for +publisher:"University of Arizona" +contributor:("Banerjee, Sourav"). Showing records 1 – 2 of 2 total matches.

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University of Arizona

1. Kumar Yadav, Susheel. Damage Detection and Characterization in Plate Like Structures .

Degree: 2013, University of Arizona

Large civil infrastructure systems all over the world have become an integral part of our civilization. The inspection and maintenance of these structures for public safety is a difficult task. The assessment of integrity of such huge structures due to local damages is even more difficult to deal with. The conventional inspections are performed manually, generally by visual examination and sometimes by more advanced techniques like ultrasonic, electromagnetic and fiber optic techniques. These inspections involve human interventions, depend on individual inspector's experience, and are time consuming. Such inspection methods may not be very useful for real time health assessment of a structure in service and as a result are not very helpful in preventing any disastrous situation through early warning. Therefore, it is very important to look for a comprehensive strategy of global integrity monitoring infused with information about local damages in the structure. For local damage assessment the current state of the health monitoring technology lacks a generalized and definitive approach to the identification and localization of damage. In past decades several signal processing tools have been used for solving different health monitoring problems but the commutability of the tools between different problems has been restricted. Fundamental reasons for this shortcoming have never been investigated in detail. In this dissertation an investigation has been carried out employing almost all promising feature extraction tools on a representative problem - a plate with rivet holes. The problem considered has radial cracks around rivet holes in a joint panel of a steel truss bridge. Such defects are very difficult to detect. Although well established, Lamb wave based nondestructive evaluation techniques are revisited and new tools are developed to address this issue. Simulation of the scattered ultrasonic wave field is carried out using the finite element method. This ultrasonic wave field is further analyzed to evaluate the integrity of the structure using various feature extraction (FE) techniques. Joint time-frequency-energy representation is obtained from ultrasonic signals recorded at various locations on the plate (joint panel) and used to extract damage sensitive features. Those features were then used to formulate a new Damage Parameter (DP) for better visualization of the crack. Results are shown to demonstrate the comparative effectiveness of these techniques. It is concluded that any particular FE technique cannot detect all possible sizes and orientations of the crack. It is suggested that the statistical occurrence and pattern of the crack must be visualized through a few selective FE techniques in a sequence. Modeling of the wave scattering phenomenon by conventional numerical techniques such as finite element method requires very fine mesh at high frequencies necessitating heavy computational power. Distributed point source method (DPSM) which is a recently developed semi-analytical technique, is applied to model… Advisors/Committee Members: Kundu, Tribikram (advisor), Kundu, Tribikram (committeemember), Banerjee, Sourav (committeemember), Frantziskonis, George (committeemember), Lansey, Kevin (committeemember).

Subjects/Keywords: Engineering Mechanics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Kumar Yadav, S. (2013). Damage Detection and Characterization in Plate Like Structures . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/306997

Chicago Manual of Style (16th Edition):

Kumar Yadav, Susheel. “Damage Detection and Characterization in Plate Like Structures .” 2013. Doctoral Dissertation, University of Arizona. Accessed November 19, 2019. http://hdl.handle.net/10150/306997.

MLA Handbook (7th Edition):

Kumar Yadav, Susheel. “Damage Detection and Characterization in Plate Like Structures .” 2013. Web. 19 Nov 2019.

Vancouver:

Kumar Yadav S. Damage Detection and Characterization in Plate Like Structures . [Internet] [Doctoral dissertation]. University of Arizona; 2013. [cited 2019 Nov 19]. Available from: http://hdl.handle.net/10150/306997.

Council of Science Editors:

Kumar Yadav S. Damage Detection and Characterization in Plate Like Structures . [Doctoral Dissertation]. University of Arizona; 2013. Available from: http://hdl.handle.net/10150/306997


University of Arizona

2. Hafezi, Mohammad Hadi. Peridynamic Modeling and Extending the Concept to Peri-Ultrasound Modeling .

Degree: 2017, University of Arizona

In this dissertation, a novel fast modeling technique called peri-ultrasound that can model both linear and nonlinear ultrasonic behavior of materials is developed and implemented. Nonlinear ultrasonic response can detect even very small material non- linearity. Quantification of the material nonlinearity at the early stages of damage is important to avoid catastrophic failure and reduce repair costs. The developed model uses the nonlocal continuum-based peridynamic theory which was found to be a good simulation tool for handling crack propagation modeling, in particular when multiple cracks grow simultaneously. The developed peri-ultrasound modeling tool has been used to model the ultrasonic response at the interface of two materials in presence of an interface crack. Also, the stress wave propagation in a half-space (or half-plane for a 2-dimensional problem) with boundary loading is investigated using peri-ultrasound modeling. In another simulation, well-established two-dimensional Lamb's problem is investigated where the results are verified against available analytical solution. Also, the interaction between the surface wave and a surface breaking crack is studied. Advisors/Committee Members: Kundu, Tribikram (advisor), Kundu, Tribikram (committeemember), Brio, Moysey (committeemember), Aifantis, Katerina E (committeemember), Banerjee, Sourav (committeemember), Dao, Cac M. (committeemember).

Subjects/Keywords: Damage; Fatigue Crack; Nonlocal Theory; Peridynamic Theory; Peri-ultrasound Modeling; Wave Propagation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hafezi, M. H. (2017). Peridynamic Modeling and Extending the Concept to Peri-Ultrasound Modeling . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/625456

Chicago Manual of Style (16th Edition):

Hafezi, Mohammad Hadi. “Peridynamic Modeling and Extending the Concept to Peri-Ultrasound Modeling .” 2017. Doctoral Dissertation, University of Arizona. Accessed November 19, 2019. http://hdl.handle.net/10150/625456.

MLA Handbook (7th Edition):

Hafezi, Mohammad Hadi. “Peridynamic Modeling and Extending the Concept to Peri-Ultrasound Modeling .” 2017. Web. 19 Nov 2019.

Vancouver:

Hafezi MH. Peridynamic Modeling and Extending the Concept to Peri-Ultrasound Modeling . [Internet] [Doctoral dissertation]. University of Arizona; 2017. [cited 2019 Nov 19]. Available from: http://hdl.handle.net/10150/625456.

Council of Science Editors:

Hafezi MH. Peridynamic Modeling and Extending the Concept to Peri-Ultrasound Modeling . [Doctoral Dissertation]. University of Arizona; 2017. Available from: http://hdl.handle.net/10150/625456

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