Simulation of acoustic emissions from delaminations and cracks in plates of aluminum and graphite

S. Fladisher, S. Jayaraman, Bernhard R. Tittmann

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The structural health monitoring of structures during active use (in service) has long been of interest to the NDE community. One technique uses passive ultrasound or Acoustic Emission (AE). However, the interpretation of the AE signals is difficult especially when the operator tries to distinguish between the growth of harmless micro-cracks and the development of harmful delaminations. This paper focuses on two types of structures, i.e., aluminum plates such as used in wing structures in aircraft and graphite plates such as encountered in aircraft disc brakes where carbon-carbon composite is used [1]. The objective in this work is to distinguish the acoustic emissions (AE) caused by delaminations from those associated with microcracking. The technical approach is to use finite element methods (FEM) to simulate AE from sources represented by piezoelectric wafers embedded in the composites. In flat panels of graphite and aluminum-alloy AE waveforms were modeled from transverse cracks and longitudinal delaminations. The results show distinct differences in the amplitudes, durations and frequency content creating a potential avenue for distinguishing between these two flaw types.

Original languageEnglish (US)
Title of host publicationNondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2008
DOIs
StatePublished - May 22 2008
EventNondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2008 - San Diego, CA, United States
Duration: Mar 11 2008Mar 13 2008

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume6934
ISSN (Print)0277-786X

Other

OtherNondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2008
CountryUnited States
CitySan Diego, CA
Period3/11/083/13/08

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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    Fladisher, S., Jayaraman, S., & Tittmann, B. R. (2008). Simulation of acoustic emissions from delaminations and cracks in plates of aluminum and graphite. In Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2008 [69340G] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 6934). https://doi.org/10.1117/12.775540