Identification of friction-coupled offshore platforms by output-only method

Tobias Friis, Karsten K. Vesterholm, Evangelos I. Katsanos, Anders Brandt, Rune Brincker

Research output: Contribution to conferencePaperResearchpeer-review

Abstract

A structural health monitoring (SHM) program can improve the structural integrity of offshore structures, however, the SHM scheme implies extraction of linear time-invariant modal parameters by Operational Modal Analysis (OMA). Inherently, the offshore platforms are nonlinear, and in many cases, the dynamics of the platforms are involving a friction-induced coupling that stems from bearings in the bridges connecting the platforms. This mechanism is causing the platforms to interchange between acting either as one system or separate systems, depending on the sliding or sticking state of the bearings. Along these lines, the present paper proposes an identification framework employing nonlinearity optimised random decrement (NORD) and OMA parameter estimation methods to identify two sets of underlying linear modes, relative to the state of the friction-induced coupling, both from the same measurement record.
Original languageEnglish
Publication date2019
Number of pages6
Publication statusPublished - 2019
Event29th International Ocean and Polar Engineering Conference (ISOPE 2019) - Honolulu, United States
Duration: 16 Jun 201921 Jun 2019

Conference

Conference29th International Ocean and Polar Engineering Conference (ISOPE 2019)
CountryUnited States
CityHonolulu
Period16/06/201921/06/2019

Keywords

  • Operational modal analysis
  • Response dependent identification
  • Friction-coupled systems
  • Nonlinear dynamics
  • Random decrement technique
  • Nonlinearity optimised random decrement
  • NORD

Cite this

Friis, T., Vesterholm, K. K., Katsanos, E. I., Brandt, A., & Brincker, R. (2019). Identification of friction-coupled offshore platforms by output-only method. Paper presented at 29th International Ocean and Polar Engineering Conference (ISOPE 2019), Honolulu, United States.
Friis, Tobias ; Vesterholm, Karsten K. ; Katsanos, Evangelos I. ; Brandt, Anders ; Brincker, Rune. / Identification of friction-coupled offshore platforms by output-only method. Paper presented at 29th International Ocean and Polar Engineering Conference (ISOPE 2019), Honolulu, United States.6 p.
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title = "Identification of friction-coupled offshore platforms by output-only method",
abstract = "A structural health monitoring (SHM) program can improve the structural integrity of offshore structures, however, the SHM scheme implies extraction of linear time-invariant modal parameters by Operational Modal Analysis (OMA). Inherently, the offshore platforms are nonlinear, and in many cases, the dynamics of the platforms are involving a friction-induced coupling that stems from bearings in the bridges connecting the platforms. This mechanism is causing the platforms to interchange between acting either as one system or separate systems, depending on the sliding or sticking state of the bearings. Along these lines, the present paper proposes an identification framework employing nonlinearity optimised random decrement (NORD) and OMA parameter estimation methods to identify two sets of underlying linear modes, relative to the state of the friction-induced coupling, both from the same measurement record.",
keywords = "Operational modal analysis, Response dependent identification, Friction-coupled systems, Nonlinear dynamics, Random decrement technique, Nonlinearity optimised random decrement, NORD",
author = "Tobias Friis and Vesterholm, {Karsten K.} and Katsanos, {Evangelos I.} and Anders Brandt and Rune Brincker",
year = "2019",
language = "English",
note = "29th International Ocean and Polar Engineering Conference (ISOPE 2019) ; Conference date: 16-06-2019 Through 21-06-2019",

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Friis, T, Vesterholm, KK, Katsanos, EI, Brandt, A & Brincker, R 2019, 'Identification of friction-coupled offshore platforms by output-only method' Paper presented at 29th International Ocean and Polar Engineering Conference (ISOPE 2019), Honolulu, United States, 16/06/2019 - 21/06/2019, .

Identification of friction-coupled offshore platforms by output-only method. / Friis, Tobias; Vesterholm, Karsten K.; Katsanos, Evangelos I.; Brandt, Anders; Brincker, Rune.

2019. Paper presented at 29th International Ocean and Polar Engineering Conference (ISOPE 2019), Honolulu, United States.

Research output: Contribution to conferencePaperResearchpeer-review

TY - CONF

T1 - Identification of friction-coupled offshore platforms by output-only method

AU - Friis, Tobias

AU - Vesterholm, Karsten K.

AU - Katsanos, Evangelos I.

AU - Brandt, Anders

AU - Brincker, Rune

PY - 2019

Y1 - 2019

N2 - A structural health monitoring (SHM) program can improve the structural integrity of offshore structures, however, the SHM scheme implies extraction of linear time-invariant modal parameters by Operational Modal Analysis (OMA). Inherently, the offshore platforms are nonlinear, and in many cases, the dynamics of the platforms are involving a friction-induced coupling that stems from bearings in the bridges connecting the platforms. This mechanism is causing the platforms to interchange between acting either as one system or separate systems, depending on the sliding or sticking state of the bearings. Along these lines, the present paper proposes an identification framework employing nonlinearity optimised random decrement (NORD) and OMA parameter estimation methods to identify two sets of underlying linear modes, relative to the state of the friction-induced coupling, both from the same measurement record.

AB - A structural health monitoring (SHM) program can improve the structural integrity of offshore structures, however, the SHM scheme implies extraction of linear time-invariant modal parameters by Operational Modal Analysis (OMA). Inherently, the offshore platforms are nonlinear, and in many cases, the dynamics of the platforms are involving a friction-induced coupling that stems from bearings in the bridges connecting the platforms. This mechanism is causing the platforms to interchange between acting either as one system or separate systems, depending on the sliding or sticking state of the bearings. Along these lines, the present paper proposes an identification framework employing nonlinearity optimised random decrement (NORD) and OMA parameter estimation methods to identify two sets of underlying linear modes, relative to the state of the friction-induced coupling, both from the same measurement record.

KW - Operational modal analysis

KW - Response dependent identification

KW - Friction-coupled systems

KW - Nonlinear dynamics

KW - Random decrement technique

KW - Nonlinearity optimised random decrement

KW - NORD

M3 - Paper

ER -

Friis T, Vesterholm KK, Katsanos EI, Brandt A, Brincker R. Identification of friction-coupled offshore platforms by output-only method. 2019. Paper presented at 29th International Ocean and Polar Engineering Conference (ISOPE 2019), Honolulu, United States.