Volume 3: Structures, Safety, and Reliability最新文献_第10页

An Efficient System Reliability Approach Against Mooring Overload Failures 针对系泊系统过载失效的有效系统可靠性方法

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-95048

Darrell Leong, Y. Low, Youngkook Kim

{"title":"An Efficient System Reliability Approach Against Mooring Overload Failures","authors":"Darrell Leong, Y. Low, Youngkook Kim","doi":"10.1115/omae2019-95048","DOIUrl":"https://doi.org/10.1115/omae2019-95048","url":null,"abstract":"\u0000 As exploration for hydrocarbon resources venture into deeper waters, offshore floating structures are increasingly required to be stationed at sites of highly uncertain environmental loading conditions. Driven by high historical mooring failure rates of severe consequences, the need for effective long-term structural reliability methods arises for mooring lines. However, system nonlinearities, high problem dimensionality, and the diversity of conceivable failure causalities their extremely low probabilities complicates the analysis. Variations on the Monte Carlo approach are robust in addressing these challenges, but at the expense of high computational costs. In this study, distributions of environmental parameters and their correlations are modelled into a joint probabilistic description. By classifying conceivable sea states across the domain, an efficient uniform sampling scheme is presented as an efficient means of assessing long-term reliability against extreme events. The proposed method was performed on a floating production unit case study situated in the hurricane-prone Gulf of Mexico, exposed to irregular wave loads. The analysis was found to provide probability estimates with negligible bias when validated against subset simulation, with significant variance reduction of mean estimators by eliminating the need to over-simulate non-critical environmental conditions. The resulting sampling density has an added advantage of being non-failure specific, enabling system reliability assessments across multiple modes and locations of failure without the need for re-analysis.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"265 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123108056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Fracture Mechanics Based Mooring Fatigue Analysis for a Semi-Submersible Subjected to Triple Narrow-Band Loading Processes 基于断裂力学的半潜船系泊疲劳分析

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-95108

X. Xue, Nian-Zhong Chen, Y. Pu

{"title":"Fracture Mechanics Based Mooring Fatigue Analysis for a Semi-Submersible Subjected to Triple Narrow-Band Loading Processes","authors":"X. Xue, Nian-Zhong Chen, Y. Pu","doi":"10.1115/omae2019-95108","DOIUrl":"https://doi.org/10.1115/omae2019-95108","url":null,"abstract":"\u0000 In the general offshore operating locations, mooring systems are normally considered to be primarily affected by environmental loadings induced by waves, wind and current. WF motion induced by first-order waves, LF motion induced by second-order waves and wind would make the most contribution to the fatigue damage of mooring lines. However, it was reported recently that in the Gulf of Mexico (GoM), the fatigue life of mooring lines can be significantly affected by the vortex induced motion (VIM) induced by loop current. The aim of this presented paper is to address the influence of VIM on fatigue life of the mooring system operating at the central of the GoM through performing a fracture mechanics (FM) based fatigue analysis for an offshore mooring system.\u0000 A frequency-domain mooring analysis for the semi-submersible is conducted where WF motion induced by first-order waves, LF motion induced by second-order waves and wind, and VIM induced by loop current are taken into account. WF motion, LF motion and VIM are treated as three independent loading processes. A wide-band loading combination method is then used for predicting the loading processes acting on the mooring system combining WF motion, LF motion and VIM. A fracture mechanics based analysis is performed to examine the fatigue life of mooring system, in which initial surface cracks in previous existence are assumed to grow from the surfaces of mooring chain links connecting to the fairleads. The stress intensity factor ranges to estimate the crack growth in the FM based analysis are obtained from a finite element (FE) analysis.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126927688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantification of Predicted Wave Forces From Distant Elevation Measurements 从远距离高程测量预测波浪力的量化

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-96289

Spencer T Hallowell, S. Arwade, H. Johlas, P. Lomónaco, A. Myers

{"title":"Quantification of Predicted Wave Forces From Distant Elevation Measurements","authors":"Spencer T Hallowell, S. Arwade, H. Johlas, P. Lomónaco, A. Myers","doi":"10.1115/omae2019-96289","DOIUrl":"https://doi.org/10.1115/omae2019-96289","url":null,"abstract":"\u0000 The vast spatial scale of offshore structures causes wave loading to be correlated amongst nearby structural members. Certain engineering activities including health monitoring, maintenance, and preliminary design of offshore structures requires the prediction of wave forces on said structural members. The high cost and low availability of environmental wave measurements requires the reconstruction of wave kinematics and force profiles to accurately capture the forcing history on offshore structures. A method for predicting wave forces on a cylinder from nearby wave elevation measurements is proposed. The formulation utilizes the Fast Fourier Transform to calculate wave kinematics propagation in the frequency domain and applies the kinematics to the Morison equation for calculation of cylinder forces. The prediction equations are applied to three types of waves: regular periodic waves, random irregular waves, and solitary breaking waves, and the error in both elevation prediction and force prediction when compared to measured values is calculated. The force prediction equations were shown to perform best for small wave heights, with errors as low as 5% in the force predictions for small regular and irregular waves. The error in force prediction increases nonlinearly with the increase in wave height due to the deficiencies of the linear dispersion relationship used in the formulation.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131705276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Simplifying Methods for Fatigue Analysis of Risers 立管疲劳分析的简化方法

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-95386

L. C. Pereira, P. Videiro, L. Sagrilo

{"title":"Simplifying Methods for Fatigue Analysis of Risers","authors":"L. C. Pereira, P. Videiro, L. Sagrilo","doi":"10.1115/omae2019-95386","DOIUrl":"https://doi.org/10.1115/omae2019-95386","url":null,"abstract":"\u0000 This work presents methods for reducing computational costs to estimate fatigue damage in riser structures by simplifying the sea state matrix to be solved in time domain by finite element analyses. Two different methods are proposed: The Equivalent Damage Method (EDM), which is a lump block method with an innovative formulation using vessel linearized response to determine significant sea states; and the Response Surface Method (RSM), which uses results from a few sea states to estimate results for other intermediary scenarios required for the fatigue analysis. Basic assumptions and guidance on how to apply the proposed methods are explained through the text.\u0000 The methods are used to solve an example of a Steel Catenary Riser (SCR) connected to a Semi-Submersible vessel, resulting in a reduction of almost 80% of the required computing time. Results show accurate values for damage estimates at the top of the riser, and limitations at the touch down zone. Advantages and disadvantages of each method are discussed in detail, demonstrating that they can be used with discretion at early design stages to estimate fatigue damage of risers, umbilicals and mooring lines in general.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"40 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128844816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Numerical Study on the Dynamical Characteristic and Impact Force Between Vessel With Rake Bow and Bridge Pier 前艏船与桥墩间动力特性及冲击力的数值研究

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-95602

M. Xu, Ziwen Zhang, Xiao Qiang Zhang, J. Pan, Y. Huang

引用次数: 0

Fatigue Assessment of “Corroded” Mooring Chain “腐蚀”系泊链的疲劳评价

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-96191

D. Baker, Zhen Li, Sue Wang, Xiying Zhang, Yunliang Shao, Harry Li, X.H. Zhan, Linfang Zhu, Xing Tao

{"title":"Fatigue Assessment of “Corroded” Mooring Chain","authors":"D. Baker, Zhen Li, Sue Wang, Xiying Zhang, Yunliang Shao, Harry Li, X.H. Zhan, Linfang Zhu, Xing Tao","doi":"10.1115/omae2019-96191","DOIUrl":"https://doi.org/10.1115/omae2019-96191","url":null,"abstract":"\u0000 Assessment of corroded mooring chain for continued service is a challenging task faced by industry. Current best practice relies heavily on qualitative inspection information collected during inspection campaign. There has been little investigation into this practice and whether it is an appropriate technique or can be improved. To address this issue, the Fatigue of Corroded Mooring Chains (FoCCs) Joint Industry Project (JIP), initiated in 2016 with fifteen (15) participating organizations, including oil majors, chain manufactures, consulting firms, and classification societies, to examine assessment methods for evaluating remaining fatigue life. JIP teams were formed to progress fatigue testing and finite element objectives. One such team, comprised of ExxonMobil, ABS and Asian Star Anchor Chain, has performed an additional series of fatigue tests beyond the core JIP work effort.\u0000 A fatigue test was conducted to 1) demonstrate the utility of finite element analysis in the assessment of fatigue life and 2) demonstrate performance of simulated damage. This unique fatigue test program was conducted on mooring chain with manufactured “corrosion pits” of different dimensions. All chain surface features were digitally recorded and converted into finite element models. These models were subsequently analyzed to compare with test results — both cycle count and failure location. This paper presents the findings from these fatigue tests and finite element analyses and how they can be utilized for assessment of remaining fatigue life.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131304491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Squall Detection and Analysis From Historical Satellite Data 基于历史卫星数据的飑探测与分析

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-96549

L. Renac, D. Hurdle, F. Enet, J. Vroom

{"title":"Squall Detection and Analysis From Historical Satellite Data","authors":"L. Renac, D. Hurdle, F. Enet, J. Vroom","doi":"10.1115/omae2019-96549","DOIUrl":"https://doi.org/10.1115/omae2019-96549","url":null,"abstract":"\u0000 Thunderstorms and squalls (fronts of contiguous thunderstorms) are associated with short but intense local winds that have a great impact on operability or design conditions for moored ship operations in the coastal zone. The brevity and local scale of such events makes them difficult to capture using standard measurement data and usually requires dedicated long-term measurement campaigns. Because the standard measurements available are usually based on 10-minute averages taken once an hour, such data is often not available. In the absence of conventional measured data, the use of satellite data can provide useful design data if analyzed and applied with caution. We present two case studies (West Africa and Brazil) where squalls have been identified in satellite data and used for extreme value analysis (EVA) to support the design of intermediate water depth mooring systems. The detection of squalls is confirmed with satellite imagery and the handling of this data for the EVA is presented in detail with assumptions made and the sensitivity of the results to these assumptions. The impact on design values is also discussed for both geographic locations.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"307 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114096694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Low-Cycle-Fatigue Crack Closure Effect of Ship Cracked Plate Considering the Accumulative Plastic Damage 考虑累积塑性损伤的舰船裂纹板低周疲劳裂纹闭合效应

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-95230

Yuelin Song, Ping Yang, Ziya Peng, Wei Jiang, K. Hu

引用次数: 0

Airgap Assessment of Semi-Submersible Accounting for Simultaneous Occurrence of Wind Sea and Swell 考虑风海涌浪同时发生的半潜式气隙评估

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-95144

S. Haver, J. Patiño

引用次数: 1

Quantitative Evaluation of Ship Operational Effect in Actually Encountered Sea States 船舶在实际遇到海况时作战效果的定量评价

Volume 3: Structures, Safety, and Reliability Pub Date : 2019-06-09 DOI: 10.1115/omae2019-95121

Rei Miratsu, Tsutomu Fukui, Toshiyuki Matsumoto, T. Zhu

{"title":"Quantitative Evaluation of Ship Operational Effect in Actually Encountered Sea States","authors":"Rei Miratsu, Tsutomu Fukui, Toshiyuki Matsumoto, T. Zhu","doi":"10.1115/omae2019-95121","DOIUrl":"https://doi.org/10.1115/omae2019-95121","url":null,"abstract":"\u0000 Since ships are being operated under consideration of the safety for lives and properties, economical reasons and so on, the sea states in natural phenomena and those actually encountered by ships are thought to be different, the latter has some effects of human operational factors (called as “ship operational effect”). Evaluating the ship operational effect in detail is important to consider rational wave design loads for hull structure strength.\u0000 The purpose of this study is to evaluate the ship operational effect in actually encountered sea states quantitatively. As the first report, comparison was made between IACS Rec.34 (a kind of the observed sea states in natural phenomena) and forecasted sea states corresponding to AIS data of ships (a kind of the sea states data actually encountered by ships) on the North Atlantic. Comparisons among the encountered significant wave heights by merchant ships such as bulk carriers, oil tankers and container ships and those specified in IACS Rec. 34 were carried out. Furthermore, the wave headings regarding the encountered waves were investigated. Finally, the relationships between encountered significant wave heights and ship speeds were derived to confirm the ship operational effect.\u0000 It was confirmed from the results that the actually encountered wave heights were smaller than those in IACS Rec. 34, through comparing the exceedance probability of the significant wave heights for each type of ships and IACS Rec. 34. The exceedance probability in the encountered beam seas is relatively lower compared with those in the encountered head and following seas. The results also show that ship speeds decrease when the encountered wave heights become larger.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126228396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3