Structural Engineering and Mechanics

  • 제38권3호
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  • Pages.349-359
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  • 2011
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  • 1225-4568(pISSN)
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  • 1598-6217(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Theoretical research on the identification method of bridge dynamic parameters using free decay response

  • 투고 : 2009.08.12
  • 심사 : 2011.01.15
  • 발행 : 2011.05.10
⟨ 이전 논문 다음 논문 ⟩

초록

Input excitation and output response of structure are needed in conventional modal analysis methods. However, input excitation is often difficult to be obtained in the dynamic load test of bridge structures. Therefore, what attracts engineers' attention is how to get dynamic parameters from the output response. In this paper, a structural experimental modal analysis method is introduced, which can be used to conveniently obtain dynamic parameters of the structure from the free decay response. With known damping coefficients, this analysis method can be used to identify the natural frequencies and the mode shapes of MDOF structures. Based on the modal analysis theory, the mathematical relationship of damping ratio and frequency is obtained. By using this mathematical relationship to improve the previous method, an improved experimental modal analysis method is proposed in this paper. This improved method can overcome the deficiencies of the previous method, which can not identify damping ratios and requires damping coefficients in advance. Additionally, this improved method can also identify the natural frequencies, mode shapes and damping ratios of the bridge only from the free decay response, and ensure the stability of identification process by using modern mathematical means. Finally, the feasibility and effectiveness of this method are demonstrated by a numerical example of a simply supported reinforced concrete beam.

키워드

참고문헌

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피인용 문헌

  1. Dynamic response analysis of generally damped linear system with repeated eigenvalues vol.42, pp.4, 2012, https://doi.org/10.12989/sem.2012.42.4.449