Identification of an open crack in a beam with variable profile by two resonant frequencies Articles uri icon

publication date

  • March 2018

start page

  • 839

end page

  • 859

issue

  • 5

volume

  • 24

international standard serial number (ISSN)

  • 1077-5463

electronic international standard serial number (EISSN)

  • 1741-2986

abstract

  • We consider the identification of a single open crack in a simply supported beam having nonuniform smooth profile and undergoing infinitesimal in-plane flexural vibration. The profile is assumed to be symmetric with respect to the mid-point of the beam axis. The crack is modeled by inserting a rotational linearly elastic spring at the damaged cross-section. We establish sufficient conditions for the unique identification of the crack by a suitable pair of natural frequency data, and we present a constructive algorithm for determining the damage parameters. The result is proved under a technical a priori assumption on the zeros of a suitable function determined in terms of the eigenfunctions of the problem. Extensions to beams under different sets of end conditions are also discussed. Theoretical results are confirmed by an extensive numerical investigation, both on simulated and experimental data.

keywords

  • Damage identification; cracks; resonant frequencies; nonuniform beams; inverse problems