Recent Trends in the Analysis and Design of Offshore Platforms in Seismic Regions

2013 ◽  
Author(s):  
Frank Puskar ◽  
Albert Ku ◽  
Richard Litton
Keyword(s):  
Offshore Platforms ◽  
Analysis And Design ◽  
Recent Trends ◽  
Seismic Regions

Dynamic Analysis and Design Methods for Combustion Turbine Exhaust Silencers Employing Acoustical Baffles

2018 ◽  
Author(s):  
Agron E. Gjinolli ◽  
Jason E. Dorgan ◽  
Elden F. Ray
Keyword(s):  
Thermal Stresses ◽  
Performance Metrics ◽  
Modular Design ◽  
Seismic Analysis ◽  
Basic Function ◽  
Offshore Platforms ◽  
Analysis And Design ◽  
System Pressure ◽  
Wide Range

Combustion turbines are frequently used because they provide the most power in the smallest footprint and their modular design makes them an economical choice. These machines are used across all land-based industries as well as marine applications. The exhaust system must perform its basic function of conducting exhaust gases, which can be as high as 1250° F (675° C), safely away from the adjacent equipment and workers, and mitigate the exhaust noise under a wide range of requirements and conditions. In addition, new requirements limit shell temperatures and exhaust leakage to prevent fire or explosion of fuel gas that may leak from equipment (ATEX). This paper presents a review of the analytical processes used in the development of a silencer system to achieve optimal performance metrics. These systems are typically comprised of parallel baffles for a wide range of conditions including aero-acoustical performance, system pressure and high flow rates, thermal stresses, environmental conditions (ocean, seismic and wind), flow-induced vibration, corrosion, and fatigue – design life analysis. The specific requirements of the baffle design will be discussed through a specific case study relative to typical rectilinear (parallel) baffles used in many installations, including land-based power generation plants (Figure 1), and offshore platforms (Figure 2). This paper will discuss the analytical methods used to address these challenges via a case study. A combination of static, vibration-pulsation and dynamic structural analysis with specific attention to the seismic analysis of the parallel baffles used in skirt and structural steel supported vessels, as well as acoustical design and flow modeling techniques are used to evaluate the design options.

A Simplified Seismic Design Method for Limited-Ductility Steel Multi-Tiered Concentrically Braced Frames in Moderate Seismic Regions

2021 ◽  
Author(s):  
Eshagh Derakhshan Houreh ◽  
Ali Imanpour
Keyword(s):  
Design Method ◽  
Design Procedure ◽  
Efficient Design ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Seismic Behaviour ◽  
Analysis And Design ◽  
Concentrically Braced ◽  
Seismic Regions ◽  
Moderate Seismic Regions

Steel Multi-Tiered Concentrically Braced Frames (MT-CBFs) represent a bracing configuration where two or more concentric bracing panels are stacked between the ground and roof levels in tall single-storey buildings. A large proportion of MT-CBFs in Canada are located in low-to-moderate seismic regions (Seismic Category 0 – 3) where Limited Ductility CBFs are often preferred in design. Nevertheless, brace tensile yielding may not occur in all tiers of such frames. Additionally, the analysis and design procedure adopted by the 2019 Canadian steel design standard (CSA S16-19) can become tedious in tall frames with multiple panels. In this paper, the seismic behaviour of Limited Ductility MT-CBFs in moderate seismic regions of Canada is examined to propose a simplified design method. A set of 16 prototype MT-CBFs is designed in accordance with CSA S16-19, excluding the design requirements prescribed for MT-CBF columns. Nonlinear dynamic analyses are then performed to examine their seismic response. Finally, an efficient design method is proposed in the framework of CSA S16-19.

On the Installation Planning of a Self-Floating Offshore Platform

1979 ◽  
Vol 16 (03) ◽  
pp. 279-293
Author(s):  
Michael F. Metcalf ◽  
Michael W. Praught ◽  
Wayne O. MacDonell
Keyword(s):  
North Sea ◽  
State Of The Art ◽  
The State ◽  
Offshore Platform ◽  
Scale Model ◽  
Offshore Platforms ◽  
Analysis And Design ◽  
The North ◽  
Field Activity ◽  
The North Sea

This paper describes the installation planning for a major self-floating offshore platform that recently has been installed in the North Sea. Attention is given to the naval architectural aspects of the installation planning with particular emphasis on three phases: analysis and design, scale-model testing, and field activity preceding and during the actual installation operation. The paper describes the state-of-the-art in the installation planning of major self-floating offshore platforms of the kind being designed and built worldwide, and demonstrates the close coordination of many diverse disciplines in planning such installation operations.

scholarly journals Numerical Assessment of FPSO Platform Behaviour in Ship Collision

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Ozgur Ozguc
Keyword(s):  
Structural Integrity ◽  
Energy Levels ◽  
Offshore Structures ◽  
Offshore Platforms ◽  
Hull Girder ◽  
Analysis And Design ◽  
One Year ◽  
Criteria For Evaluation ◽  
Vessel Impact ◽  
The Impact

Offshore platforms may potentially collide with vessels of various types, including visiting ships such as supply ships and passing ships. The most critical and relevant conditions, including the analysis and design approaches are introduced. Different ship types having different displacements and structural designs exert different vessel impact loads on impacted structures. This paper presents the findings of collision impact analyses of the side shell panel, bow and stern structures of Floating Production Storage Offloading (FPSO) platforms in case of impact, e.g. by a supply vessel or methanol tanker. As collision impact simulations continue to be conducted conservatively, the colliding positions of the striking vessel are presumed to be  bow and stern only, with side force. In order to assess hull strength in collision events, non-linear FE simulations were performed by means of the MSC / DYTRAN tool, as these collision events result in more complex reactions. The degree of hull damage suffered by an FPSO vessel in different collision scenarios and at varying impact energy levels was determined in accordance with the NORSOK N-004 standard guidelines. Post-collision analyses were conducted to establish the structural integrity of the damaged hull after being exposed to environmental conditions for one year. The reduction of hull girder strength associated with the worst damage was evaluated and accounted for in the present study, providing no further damage occurs. Furthermore, the acceptance criteria for evaluation and corresponding consequences are calculated and discussed in detail. Finally, the findings from the present paper will help clarify the impact response of offshore structures and evaluation approaches and give valuable guidance for the design and operation of FPSO platforms.

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