eprintid: 10080864
rev_number: 18
eprint_status: archive
userid: 608
dir: disk0/10/08/08/64
datestamp: 2019-09-03 10:58:27
lastmod: 2021-09-26 23:11:27
status_changed: 2019-09-03 10:58:27
type: article
metadata_visibility: show
creators_name: Brownjohn, JMW
creators_name: Raby, A
creators_name: Au, SK
creators_name: Zhu, Z
creators_name: Wang, X
creators_name: Antonini, A
creators_name: Pappas, A
creators_name: D'Ayala, D
title: Bayesian operational modal analysis of offshore rock lighthouses: Close modes, alignment, symmetry and uncertainty
ispublished: inpress
divisions: UCL
divisions: B04
divisions: C05
divisions: F44
keywords: Lighthouse condition assessment system, identification,
BAYOMA, Close modes, OMA
note: This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
abstract: Despite use of GPS, lighthouses remain critical infrastructure for preserving safety of mariners and maritime trade, and the most dramatic examples are probably the Victorian era
masonry towers located on remote offshore reefs around the British Isles and exposed to
extreme weather conditions. Due to their age and likely increasing future loading, dynamic
field investigations were undertaken for condition assessment.
The field investigations of a sample of seven lighthouses had focused on experimental
modal analysis (EMA) of shaker force and acceleration response data in order to identify
sets of modal parameters (MPs) specifically including modal mass, which is useful for linking loading and response. However, the EMA missed significant useful information, which
could be recovered from operational modal analysis (OMA) of additional ambient vibration
data recorded during the field measurements, as well as from subsequent long-term monitoring of Wolf Rock lighthouse.
Horizontal vibration modes of the towers appear as pairs of modes of similar shape and
with close natural frequency due to the quasi-axisymmetric structural form(s), and the
lowest frequency pairs are most important to identify since they contribute most to
response to breaking wave impact loads. Reliably identifying both the close natural frequencies and the corresponding mode shape orientations was impossible with EMA.
date: 2019-11-01
date_type: published
official_url: https://doi.org/10.1016/j.ymssp.2019.106306
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1686309
doi: 10.1016/j.ymssp.2019.106306
lyricists_name: D'Ayala, Dina
lyricists_name: Pappas, Athanasios
lyricists_id: DDAYA16
lyricists_id: APAPP65
actors_name: Flynn, Bernadette
actors_id: BFFLY94
actors_role: owner
full_text_status: public
publication: Mechanical Systems and Signal Processing
volume: 133
article_number: 106306
issn: 1096-1216
citation:        Brownjohn, JMW;    Raby, A;    Au, SK;    Zhu, Z;    Wang, X;    Antonini, A;    Pappas, A;           Brownjohn, JMW;  Raby, A;  Au, SK;  Zhu, Z;  Wang, X;  Antonini, A;  Pappas, A;  D'Ayala, D;   - view fewer <#>    (2019)    Bayesian operational modal analysis of offshore rock lighthouses: Close modes, alignment, symmetry and uncertainty.                   Mechanical Systems and Signal Processing , 133     , Article 106306.  10.1016/j.ymssp.2019.106306 <https://doi.org/10.1016/j.ymssp.2019.106306>.    (In press).    Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10080864/1/1-s2.0-S0888327019305278-main.pdf