scholarly journals MODELLING THE WOLF ROCK LIGHTHOUSE

2020 ◽  
pp. 32
Author(s):  
Darshana Tharindra Dassanayake ◽  
Alison Raby ◽  
Edward Ransley ◽  
Alessandro Antonini ◽  
Kieran Monk ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Deep Water ◽  
Structural Response ◽  
Winter Storms

Wolf Rock lighthouse (1870) is an isolated offshore rock tower off the Southwest tip of England, built on a steep pinnacle. It is surrounded by relatively deep water, i.e. 60-70m. The lighthouse is battered by Atlantic winter storms, which result in dramatic wave impacts and exceptional runup, even reaching to its 41m high lantern level. New experimental and numerical modelling campaigns are carried out to understand the structural response of this engineering marvel. This paper will present the main results of the hydrodynamic investigations, highlighting the main issues and achievements of the first-ever attempted model of a rock lighthouse with the ambitious scale of 1:40.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/n5L5TcBiWvo

Efficient numerical modelling for the design of friction damped braced steel plane frames

1989 ◽  
Vol 16 (3) ◽  
pp. 211-218 ◽  
Author(s):  
A. Filiatrault ◽  
S. Cherry
Keyword(s):  
Numerical Modelling ◽  
Performance Index ◽  
Load Distribution ◽  
Structural Response ◽  
Computer Time ◽  
Numerical Approach ◽  
Braced Frames ◽  
Friction Damping ◽  
Braced Frame ◽  
Brake Lining

A novel friction damping system for the aseismic design of framed buildings has been proposed by Canadian researchers. The system has been shown experimentally to perform very well and is an exciting development in earthquake resistant design.The design of a building equipped with the friction damping system is achieved by determining the optimum slip load distribution to minimize structural response. The optimum slip load distribution is usually determined using the general nonlinear dynamic computer program DRAIN-2D, which requires extensive computer time and is not practical for most design offices.This paper describes a new, efficient, numerical modelling approach for the design of friction damped braced frames. The hysteretic properties of the friction devices are derived theoretically and included in a friction damped braced frame analysis program, which is adaptable to a microcomputer environment. The optimum slip load distribution is determined by minimizing a relative performance index derived from energy concepts. The new numerical approach is much more economical to use than DRAIN-2D and is of great value for the practical design of friction damped braced frames. Key words: braced frames, brake lining, performance index, damping, dynamics, earthquakes, energy, friction.

Numerical Simulation of UOE Pipe Process and its Effect on Pipe Mechanical Behavior in Deep-Water Applications

2015 ◽  
Author(s):  
Giannoula Chatzopoulou ◽  
Spyros A. Karamanos ◽  
George E. Varelis
Keyword(s):  
Deep Water ◽  
Manufacturing Process ◽  
Large Diameter ◽  
Structural Response ◽  
Structural Instability ◽  
External Pressure ◽  
Line Pipe ◽  
Simulation Tools ◽  
Large Diameter Pipes ◽  
Pipe Manufacturing

Large-diameter thick-walled steel pipes during their installation in deep-water are subjected to a combination of loading in terms of external pressure, bending and axial tension, which may trigger structural instability due to excessive pipe ovalization with catastrophic effects. In the present study, the UOE pipe manufacturing process, commonly adopted for producing large-diameter pipes of significant thickness, is considered. The study examines the effect of UOE line pipe manufacturing process on the structural response and resistance of offshore pipes during the installation process using nonlinear finite element simulation tools.

Effects of Empirical Orthogonal Functions in Simplification of Structural Response of a Deep-Water Offshore System Under Current Profile Loading

2020 ◽  
Author(s):  
Michael Binsar Lubis ◽  
Mehrdad Kimiaei ◽  
Hongwei An ◽  
Reza Azarhoush
Keyword(s):  
Deep Water ◽  
Structural Response ◽  
Time History ◽  
Empirical Orthogonal Functions ◽  
Response Analysis ◽  
Good Representation ◽  
Current Profile ◽  
Orthogonal Functions ◽  
Recent Developments ◽  
Guidelines And Standards

Abstract Typical recommended current profiles for marine operations can be found in offshore engineering guidelines and standards. However, for some offshore components (e.g. risers, umbilicals, risers) typical simplified current profiles can easily lead to unrealistic and conservative results. Due to recent developments in current measuring technology, current speed for deep water location can be easily acquired. However, the current speeds are usually recorded for long periods and in many measurement points along the water column. Hence, finding the extreme current profile based on the recorded time-history data is not an easy task since it needs excessive computational efforts. To determine the overall response of an offshore system, various methods have been developed to minimize the required computational efforts in working with big number of irregular current profiles. Mode-based analysis using empirical orthogonal functions is one of these methods. Total number of the utilized modes plays an important role in the numerical complexity of the problem as well as the accuracy of the results. In this study, for a given deep water location, the effects of the reduced number of modes are investigated through response analysis of a simple vertical fixed slender structure under thousands of current profiles. It is found that the reduced-mode profile can produce a good representation of the measured current profile, however it tends to underestimate the structural response.

Risk Mitigation Through the Application of New Power Umbilical Technology

2012 ◽  
Author(s):  
Alan Dobson ◽  
Steven Frazer
Keyword(s):  
Aluminum Alloy ◽  
Deep Water ◽  
Risk Mitigation ◽  
Electrical Power ◽  
Structural Response ◽  
Power Cable ◽  
Enabling Technology ◽  
Effect Analysis ◽  
Design Case Study

This paper describes the substantial service life improvements that can be achieved through a new, high technology solution developed for deep water electrical power umbilical and cable applications. The new design represents an enabling technology for power cable projects in the deepest and most dynamic waters, provides a lower risk solution for risers in highly stressed conditions and can give a technically improved solution for the range of electrical power umbilical application. The significant advantages of aluminum alloy cable bundles over traditional copper cable bundles under static and dynamic loading associated with a typical deep water floating installation are presented. A design case study is used to illustrate improvements in structural response and fatigue life associated with the aluminum alloy cable cores against conventional technologies. The paper concludes with an overview of the associated risk reduction through the implementation of the aluminum alloy cables in the form of a failure mode and effect analysis.

scholarly journals Remote Sensing Observations of Dominant Breaking Waves in Intermediate to Deep Water from a Lighthouse During Storm Conditions

2021 ◽  
Author(s):  
Caio Eadi Stringari ◽  
Jean-François Filipot ◽  
Fabien Leckler ◽  
Rui Duarte
Keyword(s):  
Remote Sensing ◽  
Deep Water ◽  
Wave Breaking ◽  
Rogue Waves ◽  
Breaking Waves ◽  
Offshore Structures ◽  
Video Data ◽  
Occurrence Rate ◽  
Winter Storms ◽  
Technical Issues

Wave breaking is one of the most important yet poorly understood water wave phenomena. It is via wave breaking that waves dissipate most of their energy and the occurrence of wave breaking directly influences several environmental processes, from ocean-atmosphere gas exchanges to beach morphodynamics. Large breaking waves also represent a major threat for navigation and for the survivability of offshore structures. This paper provides a systematic search for intermediate to deep water breaking waves with particular focus on the elusive occurrence of plunging breakers. Using modern remote sensing and deep learning techniques, we identify and track the evolution of over four thousand unique wave breaking events using video data collected from La Jument lighthouse during ten North Atlantic winter storms. Out of all identified breaking waves (Nb=4683), ≈22% were dominant breaking waves, that is, waves that have speeds within [0.77cp, 1.43cp], where cp is the peak wave speed. Correlations between the occurrence rate of dominant breaking waves (that is, waves per area and time per peak wave period) and wave steepness and wave age were observed. As expected, the number of identified plunging waves was small and six waves of all detected breaking waves, or 0.13%, could undoubtedly be considered as plunging waves. Two waves were also identified as unusually large, or rogue waves. Although afflicted by several technical issues, the data presented here provides a good indication that the probability of occurrence of plunging waves should be better incorporated into the design of offshore structures, particularly the ones that aim to harvest energy in offshore environments.

scholarly journals Structural response of cold-formed lipped Z purlins – Part 2 numerical modelling and optimisation of lip size

2021 ◽  
Vol 161 ◽  
pp. 107453 ◽  
Author(s):  
Meshal Almatrafi ◽  
Marios Theofanous ◽  
Samir Dirar ◽  
Marina Bock
Keyword(s):  
Numerical Modelling ◽  
Structural Response

Pinching in Steel Rack Joints: Numerical Modelling and Effects on Structural Response

2018 ◽  
Vol 19 (1) ◽  
pp. 131-146 ◽  
Author(s):  
Federico Gusella ◽  
Maurizio Orlando ◽  
Paolo Spinelli
Keyword(s):  
Numerical Modelling ◽  
Structural Response
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