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Research Papers

Frequency Response-Based Indirect Load Identification Using Optimum Placement of Strain Gages and Accelerometers

[+] Author and Article Information
Hana'a M. Alqam

Department of Mechanical Engineering,
University of Wisconsin,
Milwaukee, WI 53201
e-mail: hmalqam@uwm.edu

Anoop K. Dhingra

Department of Mechanical Engineering,
University of Wisconsin,
Milwaukee, WI 53201
e-mail: dhingra@uwm.edu

1Corresponding author.

Contributed by the Technical Committee on Vibration and Sound of ASME for publication in the JOURNAL OF VIBRATION AND ACOUSTICS. Manuscript received April 24, 2018; final manuscript received January 14, 2019; published online March 4, 2019. Assoc. Editor: Alper Erturk.

J. Vib. Acoust 141(3), 031013 (Mar 04, 2019) (12 pages) Paper No: VIB-18-1178; doi: 10.1115/1.4042709 History: Received April 24, 2018; Revised January 14, 2019

This paper presents an approach for indirect identification of dynamic loads acting on a structure through measurement of structural response at a finite number of optimally selected locations. Using the concept of frequency response function (FRF), the structure itself is considered as a load transducer. Two different types of sensors are investigated to measure the structural response. These include a use of accelerometers that leads to the identification of the displacement mode shapes. The second measurement approach involves a use of strain gages since strain measurements are directly related to imposed loads. A use of mixed strain-acceleration measurements is also considered in this work. Optimum sensor locations are determined herein using the D-optimal design algorithm that provides most precise load estimates. The concepts of indirect load identification, strain frequency response function (SFRF), displacement frequency response function (DFRF), along with the optimal locations for sensors are used in this paper. The fundamental theory for strain-based modal analysis is applied to help estimate imposed harmonic loads. The similarities and differences between acceleration-based load identification and strain-based load identification are discussed through numerical examples.

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References

Stevens, K. K. , 1987, “ Force Identification Problems—An Overview,” SEM Conference on Experimental Mechanics, Houston, TX, pp. 838–844.
Starkey, J. M. , and Merrill, G. L. , 1989, “ On the Ill-Conditioned Nature of Indirect Force Measurement Techniques,” Int. J. Anal. Exp. Modal Anal., 4(3), pp. 103–108. https://scholar.lib.vt.edu/ejournals/MODAL/
Lee, H. , and Park, Y. , 1995, “ Error Analysis of Indirect Force Determination and a Regularization Method to Reduce Force Determination Error,” Mech. Syst. Signal Process., 9(6), pp. 615–633. [CrossRef]
Okubo, N. , Tanabe, S. , and Tatsuno, T. , 1985, “ Identification of Forces Generated by a Machine Under Operating Condition,” Third International Modal Analysis Conference (IMAC), Orlando, FL, Feb. 6–9, pp. 920–927.
Hui, Z. , Xia, C. , and Xianjun, W. , 2017, “ A Review of the Methods for Solving the Ill-Conditioned Problem in Frequency Response Domain Identification of Load,” 24th International Congress on Sound and Vibration (ICSV24), London, July 23–27, p. 6614.
Hillary, B. , and Ewins, D. J. , 1984, “ The Use of Strain Gauges in Force Determination and Frequency Response Function Measurements,” Second International Modal Analysis Conference (IMAC), Orlando, FL, pp. 627–634.
Han, M. C. , and Wicks, A. L. , 1990, “ Force Determination With Slope and Strain Response Measurement,” The Eighth International Conference on Electronic Measurement and Modal Analysis Conference (IMAC), Kissimmee, FL, Feb. 8–11, pp. 365–372.
Reich, G. W. , and Park, K. C. , 2001, “ A Theory for Strain-Based Structural System Identification,” ASME J. Appl. Mech., 68(4), pp. 521–527. [CrossRef]
Hong, K. , Lee, J. , Choi, S. W. , Kim, Y. , and Park, H. S. , 2013, “ A Strain-Based Load Identification Model for Beams in Building Structures,” Sensors, 13(8), pp. 9909–9920. [CrossRef] [PubMed]
Yang, J. , and Yoshizawa, T. , 2014, “ Indirect Force Identification Using Strain Sensor,” 21st International Congress on Sound and Vibration (ICSV21), Beijing, China, July 13–17, p. 3288.
Manzato, S. , and Santos, F. , 2014, “ Combined Accelerometers-Strain Gauges Operational Modal Analysis and Application to Wind Turbine Data,” Ninth International Conference on Structural Dynamics (EURODYN '14), Porto, Portugal, June 30–July 2, pp. 3675–3682.
Masroor, S. A. , and Zachary, L. W. , 1991, “ Designing an All-Purpose Force Transducer,” Exp. Mech., 31(1), pp. 33–35. [CrossRef]
Khoo, S. Y. , and Ismail, Z. , 2014, “ Impact Force Identification With Pseudo-Inverse Method on a Lightweight Structure for Under-Determined, Even-Determined and Over-Determined Cases,” Int. J. Impact Eng., 63, pp. 52–62. [CrossRef]
Govers, Y. , and Jelicic, G. , 2016, “ The Use of Strain Sensors for Modal Identification of Aeroelastic Structures,” International Conference on Noise and Vibration Engineering, Leuven, Belgium, Sept. 19–23, pp. 2207–2216.
Thite, A. , and Thompson, D. , 2006, “ Selection of Response Measurement Locations to Improve Inverse Force Determination,” Appl. Acoust., 67(8), pp. 797–818. [CrossRef]
Daraji, A. H. , Hale, J. M. , and Ye, J. , 2017, “ New Methodology for Optimal Placement of Piezoelectric Sensor/Actuator Pairs for Active Vibration Control of Flexible Structures,” ASME J. Vib. Acoust., 140(1), p. 011015. [CrossRef]
Gupta, D. K. , and Dhingra, A. K. , 2013, “ An Inverse Approach on Load Identification From Optimally Placed Accelerometers,” ASME Paper No. DETC2013-12494.
Gupta, D. K. , and Dhingra, A. K. , 2013, “ Input Load Identification From Optimally Placed Strain Gages Using D-Optimal Design and Model Reduction,” Mech. Syst. Signal Process., 40(2), pp. 556–570. [CrossRef]
Johnson, M. , and Nachtsheim, C. J. , 1983, “ Some Guidelines for Constructing Exact D-Optimal Designs on Convex Design Spaces,” Technometrics, 25(3), pp. 271–277. https://www.jstor.org/stable/1268612
Mitchell, T. J. , 1974, “ An Algorithm for the Construction of ‘D-Optimal’ Experimental Designs,” Technometrics, 16(2), pp. 203–210. https://www.jstor.org/stable/1267940
Szwedowicz, J. , Senn, S. M. , and Abhari, R. S. , 2002, “ Optimum Strain Gage Application to Bladed Assemblies,” ASME J. Turbomach., 124(4), pp. 606–613. [CrossRef]
Akbar, E. , and Masoud, S. , 2010, “ Finite Element Model Updating Using Frequency Response Function of Incomplete Strain Data,” AIAA J., 48(7), pp. 1420–1433. [CrossRef]

Figures

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Fig. 1

Complete description of indirect load identification in frequency domain

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Fig. 2

Finite element model of a cantilevered beam

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Fig. 3

(a) Difference between applied load and predicted load using SFRF-10 retained modes and seven strain gages and (b) difference between applied load and predicted load using SFRF-20 retained modes and seven strain gages

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Fig. 4

(a) Difference between applied load and predicted load using DFRF-10 retained modes and seven accelerometers and (b) difference between applied load and predicted load using DFRF-20 retained modes and seven accelerometers

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Fig. 5

(a) Difference between applied load and predicted load using SDFRF-10 retained modes with five strain gages and two accelerometers and (b) difference between applied load and predicted load using SDFRF-20 retained modes with five strain gages and two accelerometers

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Fig. 6

(a) Difference between applied load and predicted load using SDFRF-10 retained modes with nonoptimally placed sensors and (b) difference between applied load and predicted load using SDFRF-20 retained modes with nonoptimally placed sensors

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Fig. 7

Finite element model of the horn bracket

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Fig. 8

(a) Difference between applied load and predicted load using SFRF-15 retained modes and ten strain gages and (b) difference between applied load and predicted load using SFRF-25 retained modes and ten strain gages

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Fig. 9

(a) Difference between applied load and predicted load using DFRF-15 retained modes and ten accelerometers and (b) difference between applied load and predicted load using DFRF-25 retained modes and ten accelerometers

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Fig. 10

(a) difference between applied load and predicted load using SDFRF-15 retained modes with seven strain gages and three accelerometers and (b) difference between applied load and predicted load using SDFRF-15 retained modes with seven strain gages and three accelerometers

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