Structural Health Monitoring Using Modal Strain Energy

Volume 2: 11th Biennial Conference on Reliability, Stress Analysis, and Failure Prevention; 7th International Conference on Design Theory and Methodology; JSME Symposium on Design and Production; Mechanical Design Education and History; Computer-Integrated Concurrent Design Conference ◽

10.1115/detc1995-0151 ◽

1995 ◽

Author(s):

Robert S. Ballinger ◽

David W. Herrin

Keyword(s):

Dynamic Response ◽

Modal Analysis ◽

Strain Energy ◽

Structural Integrity ◽

Dynamic Structure ◽

Experimental Modal Analysis ◽

Modal Strain Energy ◽

Various Boundary Conditions ◽

Structural Region ◽

High Strain Energy

Abstract This research combines analytical and experimental modal analysis techniques to verify the structural integrity or monitor the “health” of a dynamic structure. Central to the procedure is the development of a baseline dynamic fingerprint model of the structure. The dynamic fingerprint is verified with experimental modal analysis and correlation. After the structure is placed into service, damage can be determined by comparing the current dynamic response with the baseline dynamic fingerprint response. The unique aspect of this procedure is that the current dynamic response is enforced on the undamaged baseline dynamic fingerprint model. Should damage exist, the structure is forced to deform in an unnatural manner, and high strain energy results. Significant differences in the normalized modal or operating strain energy density identify structural regions where a loss of stiffness, weakening of the structure, and/or damage has occurred. This identification of a potentially “unhealthy” structural region allows a quick visual inspection of the region or further analytical and/or experimental submodelling of the area to precisely identify the damage. The method is ideally suited to CAE application. The method is demonstrated analytically and experimentally for two structures: an eight-bay cantilevered truss structure and a rectangular plate with various boundary conditions.

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Looseness localization for bolted joints using Bayesian operational modal analysis and modal strain energy

Advances in Mechanical Engineering ◽

10.1177/1687814018808698 ◽

2018 ◽

Vol 10 (11) ◽

pp. 168781401880869 ◽

Cited By ~ 3

Author(s):

Yu-Jia Hu ◽

Wei-Gong Guo ◽

Cheng Jiang ◽

Yun-Lai Zhou ◽

Weidong Zhu

Keyword(s):

Modal Analysis ◽

Strain Energy ◽

Damage Index ◽

Operational Modal Analysis ◽

Modal Identification ◽

Bolted Joints ◽

Mode Shapes ◽

Bolted Connections ◽

Modal Strain Energy ◽

Beam Structures

Bayesian operational modal analysis and modal strain energy are employed for determining the damage and looseness of bolted joints in beam structures under ambient excitation. With this ambient modal identification technique, mode shapes of a damaged beam structure with loosened bolted connections are obtained based on Bayesian theory. Then, the corresponding modal strain energy can be calculated based on the mode shapes. The modal strain energy of the structure with loosened bolted connections is compared with the theoretical one without bolted joints to define a damage index. This approach uses vibration-based nondestructive testing of locations and looseness of bolted joints in beam structures with different boundary conditions by first obtaining modal parameters from ambient vibration data. The damage index is then used to identify locations and looseness of bolted joints in beam structures with single or multiple bolted joints. Furthermore, the comparison between damage indexes due to different looseness levels of bolted connections demonstrates a qualitatively proportional relationship.

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Optimized Design of Aluminum Cross Car Beam (CCB) Based in Modal Strain Energy Analysis

Materials Science Forum ◽

10.4028/www.scientific.net/msf.877.668 ◽

2016 ◽

Vol 877 ◽

pp. 668-673

Author(s):

Bo Liu ◽

Zhong Cai Qiu ◽

Qin Yang ◽

Ke Wang ◽

Xian He Wu

Keyword(s):

Modal Analysis ◽

Strain Energy ◽

Energy Analysis ◽

Simulation Software ◽

Optimized Design ◽

Modal Strain Energy ◽

Car Body ◽

New Energy ◽

Nature Frequency ◽

Energy Contour

An aluminium cross car beam (CCB) for new energy is designed with CATIA. And then,modal analysis is taken by using simulation software-NASTRAN. As nature frequencies can't meet the design target, optimization is performed according to the modal strain energy contour. After structure is strengthen, the first vertical nature frequency of the aluminum CCB(mounted on trimmed car body,with closures and interiors) reaches 35.4Hz.While the first lateral nature frequency reaches 36.5 Hz. Besides,comparing to steel CCB,the weight of the aluminum CCB reduces by4.4 kilogram.

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Article Review : EXPERIMENTAL MODAL ANALYSIS AND DYNAMIC RESPONSE PREDICTION OF PC BOARDS WITH SURFACE MOUNT ELECTRONIC COMPONENTS T.L. Wong, K.K. Stevens, G. Wang J. Electronic Packaging, Trans. ASME 113 (3), pp 244-249 10 figs, 2 tables, 15 refs (Sept 1991)

The Shock and Vibration Digest ◽

10.1177/058310249302500706 ◽

1993 ◽

Vol 25 (7) ◽

pp. 13-13

Author(s):

R. H. Volin

Keyword(s):

Dynamic Response ◽

Modal Analysis ◽

Electronic Packaging ◽

Response Prediction ◽

Experimental Modal Analysis ◽

Electronic Components ◽

Surface Mount ◽

Trans Asme

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Wing Flutter Analysis Parameters during Flight

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.722.93 ◽

2014 ◽

Vol 722 ◽

pp. 93-96

Author(s):

Wei Long ◽

Yan Liu ◽

Jia Ming Cao

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Strain Energy ◽

Dynamic Structure ◽

Frequency Error ◽

Element Analysis ◽

Modal Strain Energy ◽

Modal Frequency ◽

Wing Flutter ◽

Flutter Analysis

This paper adapts finite element analysis of dynamic structure to analysis airfoil based on the phenomenon that torsion coupling may happen to airfoil during flying,, which verifies flutter mechanism of swing under subsonic and transonic condition. Modal frequency error can be changed into stiffness error by error analysis. The errors of bending and torsion frequency are verified by adjusting stiffness and mass distribution. Meanwhile the concept of modal strain energy is introduced to character and identify different positions and structures of damages.

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A finite element analysis of idealized damage in beam structures

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/0954406041991251 ◽

2004 ◽

Vol 218 (9) ◽

pp. 921-929 ◽

Cited By ~ 1

Author(s):

K A Alnefaie

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Modal Analysis ◽

Strain Energy ◽

Damage Index ◽

Experimental Modal Analysis ◽

Element Analysis ◽

Beam Structures ◽

Sensitive Parameter ◽

Moment Index

The strain energy damage index (SEDI) and a nominally similar parameter called SEDI2 are reported to be insensitive to the magnitude of the underlying damage in beams, although they do help to locate the damage itself. A new damage-sensitive parameter, the modal moment index (MMI), is introduced. It is shown that the MMI also ‘jumps’ at the location of damage in the beam. In addition, it is established that the magnitude of the MMI is closely related to the decrease in relative modulus. It is concluded hence that the MMI seems to be a damage-sensitive parameter with potential for application in experimental modal analysis.

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Effect of Bass Bar Tension on Modal Parameters of a Violin's Top Plate

Archives of Acoustics ◽

10.2478/aoa-2014-0015 ◽

2015 ◽

Vol 39 (1) ◽

pp. 145-149 ◽

Cited By ~ 3

Author(s):

Ewa B. Skrodzka ◽

Bogumił B.J. Linde ◽

Antoni Krupa

Keyword(s):

Modal Analysis ◽

Experimental Modal Analysis ◽

Mode Shapes ◽

Modal Parameters ◽

Normal Value ◽

Modal Damping

Abstract Experimental modal analysis of a violin with three different tensions of a bass bar has been performed. The bass bar tension is the only intentionally introduced modification of the instrument. The aim of the study was to find differences and similarities between top plate modal parameters determined by a bass bar perfectly fitting the shape of the top plate, the bass bar with a tension usually applied by luthiers (normal), and the tension higher than the normal value. In the modal analysis four signature modes are taken into account. Bass bar tension does not change the sequence of mode shapes. Changes in modal damping are insignificant. An increase in bass bar tension causes an increase in modal frequencies A0 and B(1+) and does not change the frequencies of modes CBR and B(1-).

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