Damage Detection through Analysis of Modes in a Partially Constrained Plate

Vandawaker, Robert M.; Palazotto, Anthony N.; Cobb, Richard

doi:10.1061/(asce)0893-1321(2007)20:2(90)

Cited by 8 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The MAC has been used in combination with frequency changes to detect individual damaged bolts in a constrained plate [74].…”

Section: Mode Shape Changesmentioning

confidence: 99%

Design and Analysis of Advanced Materials in a Thermal/Acoustic Environment. Delivery Order 0007: Volume 1 - Structural Health Monitoring

Grandhi¹,

Tobe²

2010

View full text Add to dashboard Cite

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information , 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YY) REPORT TYPE 3. DATES COVERED (From -To)March 2010 0A PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBERWright State University Department of Mechanical and Materials Engineering Dayton, OH 45435 SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)Air Force Research Laboratory SPONSORING/MONITORING AGENCY ACRONYM(S)Air ABSTRACTAir vehicles flying at hypersonic speeds encounter extreme thermal, aerodynamic and acoustic loads, utilizing thermal protection systems to shield the main structure from these 1oads.One type of failure in a mechanically attached thermal protection system is fastener failure. Determining structural health monitoring on the fastener health of the thermal protection system is needed and can be completed by analyzing changes in the dynamic characteristics of the system due to fastener failure. The damage detection metrics include the existing modal parameters-modal assurance criterion (MAC), partial (PMAC), and coordinate (CMAC)-as well as two new modal parameters-normalized coordinate MAC and normalized coordinate MAC X summation were investigated. Two new modal parameters were formulated to identify mode shape changes in a structure due to global damage to the structure. Two damage states caused a minimal change to the low-frequency structural dynamics and could not be localized with any of the investigated damage metrics. After the finite element model is validated for the healthy state with free-free boundary conditions, the global boundary conditions and fastener failure damage states are implemented. This damage simulation allows a better understanding of how the damage states cause low-frequency dynamic changes without requiring a experimental data for each of the damage states of interest. SUBJECT TERMSThe damage detection metrics include the existing modal parameters-modal assurance criterion, partial modal assurance criterion, and coordinate modal assurance criterion-as well as two new modal parameters-normalized coordinate modal assurance criterion and normalized coordinate modal assurance criterion summation. The existing modal parameters provide data...

show abstract

“…The MAC has been used in combination with frequency changes to detect individual damaged bolts in a constrained plate [74].…”

Section: Mode Shape Changesmentioning

confidence: 99%

Design and Analysis of Advanced Materials in a Thermal/Acoustic Environment. Delivery Order 0007: Volume 1 - Structural Health Monitoring

Grandhi¹,

Tobe²

2010

View full text Add to dashboard Cite

show abstract

“…At the early stage, the SHM methods based on experimental modal analysis were proposed to realize the objective. For example, Vandawaker et al [2] proposed to detect damage in a TPS tile by comparing mode shapes and frequencies from healthy and damaged structures. However, since high-frequency vibration modes are difficult to obtain in practice, the modal analysis-based methods mainly rely on the low-frequency vibration modes, which only represent the properties of the whole structure.…”

Section: Introductionmentioning

confidence: 99%

A Modified Time Reversal Method for Guided Wave Detection of Bolt Loosening in Simulated Thermal Protection System Panels

et al. 2018

Complexity

View full text Add to dashboard Cite

In this work, a modified time reversal method is proposed for guided wave detection and localizing loosened bolt in a complicated multibolt-jointed structure. Different from the traditional time reversal guided wave method, the response signal due to a tone burst input received at the healthy state is time reversed and recorded as a standard reemitting signal. In the detection process, this recorded standard signal is used for all damage cases to yield time reversal-focalized reconstruction signals. This largely improves the sensitivity of the focalized signal to damage state. In this paper, the peak amplitude of the focalized wave packet in the reconstructed signal is calculated and utilized as tightness index. By bonding PZT transducers at different joint locations inside the structure, multiple tightness indices, where each tightness index presents the correlation between the current joint condition to its healthy condition at the joint, can be obtained. To analyze a large number of tightness indices, a principle component analysis method is introduced, and a neural network-based loosening detection method is proposed. The proposed method is experimentally validated in a simulated double-layer bolt-jointed thermal protection system panel. Experimental results illustrate that the proposed method is effective to identify and localized the bolt loosening in complicated multibolt-jointed structure. The detection and identification of the location of multibolt loosening is realized.

show abstract

Hypersonic vehicle thermal protection system model optimization and validation with vibration tests

Tobe

Grandhi

2013

Aerospace Science and Technology

View full text Add to dashboard Cite

Damage Detection through Analysis of Modes in a Partially Constrained Plate

Cited by 8 publications

References 2 publications

Design and Analysis of Advanced Materials in a Thermal/Acoustic Environment. Delivery Order 0007: Volume 1 - Structural Health Monitoring

Design and Analysis of Advanced Materials in a Thermal/Acoustic Environment. Delivery Order 0007: Volume 1 - Structural Health Monitoring

A Modified Time Reversal Method for Guided Wave Detection of Bolt Loosening in Simulated Thermal Protection System Panels

Hypersonic vehicle thermal protection system model optimization and validation with vibration tests

Contact Info

Product

Resources

About