Estimation of mode shapes of beam-like structures by a moving lumped mass
This paper presents a method to estimate mode shapes of beam like structures by using the acceleration of a moving lumped mass. In fact, the coupled frequencies of the vehicle-beam interaction system are time varying and the non-stationary instantaneous frequencies (IFs) contain information of mode...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2021
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/150785 |
| _version_ | 1826115236818583552 |
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| author | Zhang, Yao Zhao, Haisheng Lie, Seng Tjhen |
| author2 | School of Civil and Environmental Engineering |
| author_facet | School of Civil and Environmental Engineering Zhang, Yao Zhao, Haisheng Lie, Seng Tjhen |
| author_sort | Zhang, Yao |
| collection | NTU |
| description | This paper presents a method to estimate mode shapes of beam like structures by using the acceleration of a moving lumped mass. In fact, the coupled frequencies of the vehicle-beam interaction system are time varying and the non-stationary instantaneous frequencies (IFs) contain information of mode shapes. The theoretical analysis in this paper shows that the mode shapes can be re-constructed by using the IFs; therefore, extracting mode shapes becomes a problem of IF estimation. A modified time-frequency analysis method based on weighted polynomial chirplet transform is developed to estimate the non-stationary IFs. Moreover, a new sampling algorithm based on accumulative measured energy is proposed to reconstruct the mode shapes, in which more data are sampled at the area with higher measured energy, making it more robust to noise. The proposed method is more convenient since only a lumped mass with a single accelerometer is required, and it is more practical because external exciter is not required, and the surface roughness can be the source of excitation. Numerical simulations and laboratory scale experiments have been carried out, which show that the proposed method performs well in extracting mode shapes, even if the travelling speed is high. |
| first_indexed | 2024-10-01T03:51:57Z |
| format | Journal Article |
| id | ntu-10356/150785 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:51:57Z |
| publishDate | 2021 |
| record_format | dspace |
| spelling | ntu-10356/1507852021-06-08T08:07:30Z Estimation of mode shapes of beam-like structures by a moving lumped mass Zhang, Yao Zhao, Haisheng Lie, Seng Tjhen School of Civil and Environmental Engineering Engineering::Civil engineering Mode Shape Beam Like Structures This paper presents a method to estimate mode shapes of beam like structures by using the acceleration of a moving lumped mass. In fact, the coupled frequencies of the vehicle-beam interaction system are time varying and the non-stationary instantaneous frequencies (IFs) contain information of mode shapes. The theoretical analysis in this paper shows that the mode shapes can be re-constructed by using the IFs; therefore, extracting mode shapes becomes a problem of IF estimation. A modified time-frequency analysis method based on weighted polynomial chirplet transform is developed to estimate the non-stationary IFs. Moreover, a new sampling algorithm based on accumulative measured energy is proposed to reconstruct the mode shapes, in which more data are sampled at the area with higher measured energy, making it more robust to noise. The proposed method is more convenient since only a lumped mass with a single accelerometer is required, and it is more practical because external exciter is not required, and the surface roughness can be the source of excitation. Numerical simulations and laboratory scale experiments have been carried out, which show that the proposed method performs well in extracting mode shapes, even if the travelling speed is high. Nanyang Technological University The authors would like to thank the School of Civil and Environmental Engineering at Nanyang Technological University, Singapore for kindly supporting this research topic. 2021-06-08T08:07:30Z 2021-06-08T08:07:30Z 2019 Journal Article Zhang, Y., Zhao, H. & Lie, S. T. (2019). Estimation of mode shapes of beam-like structures by a moving lumped mass. Engineering Structures, 180, 654-668. https://dx.doi.org/10.1016/j.engstruct.2018.11.074 0141-0296 0000-0002-0677-5881 https://hdl.handle.net/10356/150785 10.1016/j.engstruct.2018.11.074 2-s2.0-85057847551 180 654 668 en Engineering Structures © 2018 Elsevier Ltd. All rights reserved. |
| spellingShingle | Engineering::Civil engineering Mode Shape Beam Like Structures Zhang, Yao Zhao, Haisheng Lie, Seng Tjhen Estimation of mode shapes of beam-like structures by a moving lumped mass |
| title | Estimation of mode shapes of beam-like structures by a moving lumped mass |
| title_full | Estimation of mode shapes of beam-like structures by a moving lumped mass |
| title_fullStr | Estimation of mode shapes of beam-like structures by a moving lumped mass |
| title_full_unstemmed | Estimation of mode shapes of beam-like structures by a moving lumped mass |
| title_short | Estimation of mode shapes of beam-like structures by a moving lumped mass |
| title_sort | estimation of mode shapes of beam like structures by a moving lumped mass |
| topic | Engineering::Civil engineering Mode Shape Beam Like Structures |
| url | https://hdl.handle.net/10356/150785 |
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