Structural Safety Assessment Based on the Fatigue Analysis of the Ice-Resistant Jacket Platforms

2010 ◽  
Author(s):  
Xiaofei Che ◽  
Dayong Zhang ◽  
Qianjin Yue
Keyword(s):  
Risk Assessment ◽  
Fatigue Failure ◽  
Safety Assessment ◽  
Design Method ◽  
Hot Spot ◽  
Cyclic Stress ◽  
Fatigue Analysis ◽  
Structural Safety ◽  
Bohai Bay ◽  
General Process

Most of the ice-resistant jacket platforms in Bohai Sea have been close to or reached their service life. In order to keep the platforms perform safely, a reasonable risk assessment of the existing platforms should be considered. The hazard of the structural fatigue failure under the ice-induced vibrations is so serious, which plays an important role in the safety of the platforms. In this paper, the general process of the structural safety assessment based on the fatigue analysis is established. Firstly, risk assessment of fatigue failure needs to determine whether the cyclic stress of hot-spot induced by ice-vibrations under normal ice condition is so significant. Then, the method of estimating ice-induced fatigue life of existing platforms is developed based on the field data and the safe life design method. Finally, as an application example, the safety assessment of one old jacket platform in Bohai Bay is carried on, which can provide a warrant for owners to repair or reject platforms.

Structural Safety Assessment of Existing Ice-Resistant Jacket Platforms in Ice Zone

2009 ◽  
Author(s):  
Dayong Zhang ◽  
Qianjin Yue ◽  
Yuan Liu ◽  
Xiaofei Che
Keyword(s):  
Safety Assessment ◽  
Failure Modes ◽  
Evaluation Criteria ◽  
Offshore Structures ◽  
Life Extension ◽  
Structural Safety ◽  
Bohai Bay ◽  
Offshore Platforms ◽  
Oil And Natural Gas ◽  
Ice Loads

Until now dozens of offshore structures have been deployed in Bohai bay since the first drilling platform was erected in 1965. The oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. Full-scale measurement for many years shows the design of some ice-resistant platforms is not so sophisticated, the most significant is that ice induced vibration is the main which has caused harmful accidents in Liaodong bay of Bohai. In order to ensure security operation, structural safety assessment and life extension become key problems. In this paper, failure modes of ice resist jacket platforms, the related failure evaluation criteria, and risk grade are treated. Combined with monitoring data of ice loads, assessment strategy is presented. Lastly, as an application example, safety assessments of a practical platform in Bohai Bay are carried on.

SEISMIC RISK ASSESSMENT AND REDUCTION IN ITALY

2019 ◽  
Vol 1 (Special Issue on First SACEE'19) ◽  
pp. 55-75
Author(s):  
Fabio Sabetta
Keyword(s):  
Risk Assessment ◽  
Seismic Risk ◽  
Safety Assessment ◽  
Public Funding ◽  
Tax Incentives ◽  
Technical Training ◽  
Disaster Prevention ◽  
Existing Buildings ◽  
Seismic Risk Assessment ◽  
Post Disaster

In this paper, the main features of the policies adopted in Italy for seismic risk reduction are discussed. Particular attention is given to the Pre-disaster prevention activities such as the implementation of the building code, the seismic risk assessment for a priority scale of intervention, tax incentives and public funding for the vulnerability reduction of the existing buildings, information to population and school education, technical training of experts. The phases of response and post-disaster activities, including emergency management, search and rescue, loss scenarios, and safety assessment of buildings, are also discussed taking example from the most recent devastating earthquakes in Italy (L.Aquila 2009, Amatrice 2016).

Amended Safety Assessment of Methylchloroisothiazolinone and Methylisothiazolinone as Used in Cosmetics

2021 ◽  
Vol 40 (1_suppl) ◽  
pp. 20S-33S
Author(s):  
Christina L. Burnett ◽  
Wilma F. Bergfeld ◽  
Donald V. Belsito ◽  
Curtis D. Klaassen ◽  
Daniel C. Liebler ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Safety Assessment ◽  
Expert Panel ◽  
Quantitative Risk Assessment ◽  
Cosmetic Products ◽  
Human Data

The Expert Panel for Cosmetic Ingredient Safety (Panel) reassessed the safety of the mixture Methylchloroisothiazolinone (MCI)/Methylisothiazolinone (MI), which functions as a preservative in cosmetic products. The Panel reviewed relevant animal and human data provided in this safety assessment, and data from the previously published safety assessment of this mixture, and concluded that MCI/MI is safe in cosmetics when formulated to be nonsensitizing, based on the results of a quantitative risk assessment or similar methodology; however, at no point should concentrations exceed 7.5 ppm in leave-on products or 15 ppm in rinse-off products.

scholarly journals Development and Validation of a Post-Earthquake Safety Assessment System for High-Rise Buildings Using Acceleration Measurements

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1758
Author(s):  
Koji Tsuchimoto ◽  
Yasutaka Narazaki ◽  
Billie F. Spencer
Keyword(s):  
Safety Assessment ◽  
Large Scale ◽  
Model Updating ◽  
Safety Evaluation ◽  
Assessment System ◽  
Shaking Table ◽  
Structural Safety ◽  
High Rise ◽  
Steel Building ◽  
Earthquake Safety

After a major seismic event, structural safety inspections by qualified experts are required prior to reoccupying a building and resuming operation. Such manual inspections are generally performed by teams of two or more experts and are time consuming, labor intensive, subjective in nature, and potentially put the lives of the inspectors in danger. The authors reported previously on the system for a rapid post-earthquake safety assessment of buildings using sparse acceleration data. The proposed framework was demonstrated using simulation of a five-story steel building modeled with three-dimensional nonlinear analysis subjected to historical earthquakes. The results confirmed the potential of the proposed approach for rapid safety evaluation of buildings after seismic events. However, experimental validation on large-scale structures is required prior to field implementation. Moreover, an extension to the assessment of high-rise buildings, such as those commonly used for residences and offices in modern cities, is needed. To this end, a 1/3-scale 18-story experimental steel building tested on the shaking table at E-Defense in Japan is considered. The importance of online model updating of the linear building model used to calculate the Damage Sensitive Features (DSFs) during the operation is also discussed. Experimental results confirm the efficacy of the proposed approach for rapid post-earthquake safety evaluation for high-rise buildings. Finally, a cost-benefit analysis with respect to the number of sensors used is presented.

The Fatigue Analysis of Pressure Vessels Based on Workbench

2012 ◽  
Vol 550-553 ◽  
pp. 3082-3087
Author(s):  
Xing Ye Su ◽  
Qin Li ◽  
Hong Mei Wang
Keyword(s):  
Fatigue Failure ◽  
Chemical Industry ◽  
Pressure Vessel ◽  
Petrochemical Industry ◽  
Rapid Development ◽  
Fatigue Analysis ◽  
Pressure Vessels ◽  
Operation Condition ◽  
Key Steps

With the rapid development of petrochemical industry, the operation condition of pressure vessels under the alternating load was increasing and the probability of fatigue failure was also on the rise. As a result, pressure vessel fatigue analysis is gaining the designer's attention. This paper describes the key steps and techniques of the fatigue analysis of pressure vessel based on Workbench platform using the lock hopper of the coal chemical industry as an example.

Challenges and Developments in Navigational Risk Assessment With Large Uncertainty

2014 ◽  
Author(s):  
Xinping Yan ◽  
Jinfen Zhang ◽  
Di Zhang ◽  
Carlos Guedes Soares
Keyword(s):  
Risk Assessment ◽  
Safety Assessment ◽  
Oil Spills ◽  
Rule Base ◽  
Event Tree ◽  
Event Tree Analysis ◽  
General Application ◽  
The Past ◽  
Formal Safety Assessment ◽  
Belief Rule Base

Concerns have been raised to navigational safety worldwide because of the increasing throughput and the passing ships during the past decades while maritime accidents such as collisions, groundings, overturns, oil-spills and fires have occurred, causing serious consequences. Formal Safety Assessment (FSA) has been acknowledged to be a framework widely used in maritime risk assessment. Under this framework, this paper discusses certain existing challenges when an effective safety assessment is carried out under a variety of uncertainties. Some theories and methodologies are proposed to overcome the present challenges, e.g., Fault/Event Tree Analysis (FTA/ETA), Evidential Reasoning (ER), Bayesian Belief Network (BBN) and Belief Rule Base (BRB). Subsequently, three typical case studies that have been carried out in the Yangtze River are introduced to illustrate the general application of those approaches. These examples aim to demonstrate how advanced methodologies can facilitate navigational risk assessment under high uncertainties.

Structural Safety Assessment of a 1100 TEU Container Ship, Based on a Enhanced Long Term Fatigue Analysis

2014 ◽  
Vol 1036 ◽  
pp. 935-940
Author(s):  
Leonard Domnisoru ◽  
Ionica Rubanenco ◽  
Mihaela Amoraritei
Keyword(s):  
Safety Assessment ◽  
Safety Evaluation ◽  
Irregular Waves ◽  
Structural Safety ◽  
Random Wave ◽  
Wave Loads ◽  
Strength Assessment ◽  
Integrated Method ◽  
Hydroelastic Response

This paper is focused on an enhanced integrated method for structural safety assessment of maritime ships under extreme random wave loads. In this study is considered an 1100 TEU container test ship, with speed range 0 to 18 knots. The most comprehensive criteria for ships structural safety evaluation over the whole exploitation life is based on the long term ship structures analysis, that includes: stress hot-spots evaluation by 3D/1D-FEM hull models, computation of short term ship dynamic response induced by irregular waves, long term fatigue structure assessment. The analysis is enhanced by taking into account the ships speed influence on hydroelastic response. The study includes a comparative analysis on two scenarios for the correlation between the ships speed and waves intensity. The standard constant ship speed scenario and CENTEC scenario, with total speed loss at extreme waves condition, are considered. Instead of 20 years ship exploitation life estimated by classification societies rules from the long term structural safety criteria, the enhanced method has predicted more restrictive values of 14.4-15.7 years. The numerical analyses are based on own software and user subroutines. The study made possible to have a more realistic approach of ships structural strength assessment, for elastic and faster ships as container carriers, in compare to the standard one based only on naval rules, delivering a method with higher confidence in the designed structural safety.

scholarly journals Structural safety assessment for FLNG-LNGC system during offloading operation scenario

2017 ◽  
Vol 31 (2) ◽  
pp. 192-201 ◽  
Author(s):  
Zhi-qiang Hu ◽  
Dong-wei Zhang ◽  
Dong-ya Zhao ◽  
Gang Chen
Keyword(s):  
Safety Assessment ◽  
Structural Safety
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