The inverse medium problem for Timoshenko beams and frames : damage detection and profile reconstruction in the time-domain

We discuss a systematic methodology that leads to the reconstruction of the material profile of either single, or assemblies of one-dimensional flexural components endowed with Timoshenko-theory assumptions. The probed structures are subjected to user-specified transient excitations: we use the complete waveforms, recorded directly in the time-domain at only a few measurement stations, to drive the profile reconstruction using a partial-differential-equation-constrained optimization approach. We discuss the solution of the ensuing state, adjoint, and control problems, and the alleviation of profile multiplicity by means of either Tikhonov or Total Variation regularization. We report on numerical experiments using synthetic data that show satisfactory reconstruction of a variety of profiles, including smoothly and sharply varying profiles, as well as profiles exhibiting localized discontinuities. The method is well suited for imaging structures for condition assessment purposes, and can handle either diffusive or localized damage without need for a reference undamaged state.

Name thesis:degree_name

Master of Science in Engineering

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Civil Engineering

Grantor

The University of Texas at Austin

Year dc:date.issued

2009

Author dc:creator

• Karve, Pranav Madhav

Advisor dc:contributor.advisor

• Kallivokas, Loukas F.

Committee member dc:contributor.committeemember

• Manuel, Lance

• Inverse problem
• Total wavefield
• Damage detection
• Timoshenko beams
• Portal frames

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/2152/ETD-UT-2009-12-616

OAI identifier oai:identifier

oai:repositories.lib.utexas.edu:2152/ETD-UT-2009-12-616