Volume 3: Structures, Safety, and Reliability最新文献

{"title":"Fatigue Tests on Corroded Mooring Chains Retrieved From Various Fields in Offshore West Africa and the North Sea","authors":"Kai-tung Ma, Ø. Gabrielsen, Zhen Li, D. Baker, A. Yao, P. Vargas, Meng Luo, A. Izadparast, A. Arredondo, Linfang Zhu, N. Sverdlova, Ingrid Skutle Hogsaet","doi":"10.1115/omae2019-95618","DOIUrl":"https://doi.org/10.1115/omae2019-95618","url":null,"abstract":"\u0000 When an aged mooring system seeks a life extension, it is necessary to assess the remaining fatigue life of the corroded mooring chain. This paper summarizes the results of fatigue tests performed on mooring chain samples retrieved from six different fields in West Africa and North Sea. The impacts of corrosion on fatigue life on the samples were researched. The tests were managed under a Joint Development Project, “Fatigue of Corroded Chains (FoCCs JDP)”. The objectives of the JDP are (1) to derive a methodology for assessing the remaining fatigue life of corroded chain, (2) to develop guidance for performing reliable FEA of chain links to assess remaining fatigue life, and (3) to provide more rational basis to improve industry guidance on mooring line replacement criteria for life extension. Fatigue test procedure was defined by the fifteen (15) participating members. The procedure specified the testing parameters, including mean tension, tension range, and test frequency. Six sets of fatigue tests have been completed in seawater with the number of cycles to failure recorded. These chain samples were retrieved from floating production and storage units, e.g. FPSOs and FSUs, that were still in service. Fatigue data obtained from the tests were plotted against the design SN curves and results from fatigue testing of new chain. It was found that most of these samples have limited amount of fatigue capacity remained. Most interesting finding is that the sharpness of the surface feature on the corroded chain link has a significant impact on the remaining fatigue life. Another interesting finding is that the surface feature created by corrosion can be quite distinct and unique depending on the geophysical locations where the sample came from. These findings and test results may serve as references for life extension assessment of an aged mooring system.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"10 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":"122113846","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}

{"title":"Assessment of the Reliability of the Moorings of a Floating Structure Against the Extreme Cyclone Hazard","authors":"M. Manzocchi, Vikas Kejriwal, E. Hoo","doi":"10.1115/omae2019-96032","DOIUrl":"https://doi.org/10.1115/omae2019-96032","url":null,"abstract":"\u0000 This paper describes the methodology adopted for an analysis performed to assess the reliability of the moorings of a free weathervaning FPSO against the cyclone hazard. A joint distribution characterizing the long-term cyclone metocean conditions was fitted to a database of environmental conditions at the site of interest. A series of archetype cyclone histories were selected from the cyclone database to capture the evolving relationships between key environmental parameters during a cyclone. A response-surface model for extreme tension in the vessel moorings was developed for the short-term extreme vessel response as a function of environmental conditions by fitting the surface to an extensive series of time-domain vessel response analyses. The reliability of the mooring system was evaluated using Monte Carlo simulation by sampling from the fitted joint distribution of long-term cyclone characteristic and generating simulated cyclone time histories by scaling the archetype cyclones. The response model for short-term exceedance probability is used to develop the probability of exceedance within each simulated cyclone, and the probability of exceeding a given response is derived from the simulation.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"23 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":"117203965","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}

{"title":"A Hybrid Methodology for Maritime Accident Analysis: The Case of Ship Collision","authors":"L. P. Bowo, R. E. Prilana, M. Furusho","doi":"10.1115/omae2019-96663","DOIUrl":"https://doi.org/10.1115/omae2019-96663","url":null,"abstract":"\u0000 Human error is recognized as the most common factor that causes maritime accidents. Human Error Assessment and Reduction Technique (HEART) as a Human Reliability Assessment (HRA) has been widely applied in various industries. However, in the maritime industry, machine, media, and management are also considered as factors that can strongly affect human behavior, judgment, and other human elements. These factors are particularly relevant for bridge resource management that perform the task of maintaining a proper look-out. Therefore, this study considers the effect of those factors integrated with 4M (man, machine, media, management) factors. The study was conducted with 37 collisions accident reports from 2007–2017, using data from the NTSB and TSB-Canada. There are 229 Error Producing Condition (EPC) found in this study. The classification of the EPC to the 4M conducted in this study.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"38 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":"126429692","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}

{"title":"Explosion Response of Cold Bond Corrosion Repairs Applied to Offshore Living Quarters","authors":"Trey N. Turner, Abhimanyu Kumar","doi":"10.1115/omae2019-95810","DOIUrl":"https://doi.org/10.1115/omae2019-95810","url":null,"abstract":"\u0000 Maintaining the integrity of an aging offshore facility often requires the repair of corrosion. With advances in adhesive technology, epoxy adhesives (cold bond repairs) are increasingly being adopted to repair corrosion damage on offshore structures. Structural elements, protection barriers, and occupied buildings, for example a platform living quarters, designated as safety critical often must comply with project or facility performance standards that specify minimum design accidental loading (e.g., from fire, explosions, or impact). In addition to satisfying conventional structural design criteria, a corrosion repaired structure must also perform within acceptable limits when subjected to accidental loads. The present study outlines approaches to assess the performance of cold bond repairs subjected to accidental explosion loads. The living quarters considered in this study featured approximately 50 individual cold bond repairs; each arbitrarily located over the building’s external surfaces. Under accidental blast conditions, failure of a cold bond repair was deemed unacceptable due to the threat of pressure leakage into the building’s interior. As such, the study demanded an analysis capable of considering both the global response of the living quarters as well as the local response of cold bond repairs. There have been several studies conducted by researchers around the globe to evaluate the response characteristics of adhesive bonds. However, these studies are largely focused on experimental, local, and micromechanical analysis of adhesively bonded materials. Numerical analysis of adhesive bonds, for purposes of global structural system response assessments, especially in the case of accidental loading, appear to be nonexistent in available literature. Inspired by this gap, we present a case study involving an assessment of global structural performance of a living quarters building repaired with cold bond adhesives subject to loading due to accidental and rare events. In this study, the local behavior of cold bond adhesives was calibrated using numerical simulations of the ASTM tests specified by the adhesive vendor. The calibrated properties were implemented in finite element analyses used to validate cold bond seal plate repairs at various locations on the living quarters building. The study includes a discussion about the methods and approaches used to model cold bond repairs in a practical and efficient manner. The approach outlined herein provides a useful framework that can be adapted to similar assessments by a practicing engineer responsible for blast analysis of marine structures.","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":"133906917","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}

{"title":"Wellhead Fatigue: Benefits of Structural Reliability Analysis Applied to Groups of Wells","authors":"T. Hørte, M. Macke, A. Aardal, L. Reinås, P. Bjønnes, Erik Kristian Thon Frimanslund","doi":"10.1115/omae2019-96214","DOIUrl":"https://doi.org/10.1115/omae2019-96214","url":null,"abstract":"\u0000 This paper outlines the methodology when performing structural reliability analysis (SRA) for wellhead fatigue of a complete field compared to individual wells. The field consist of several well and template systems from different suppliers. Further this paper will emphasize on added knowledge that can arise from the field vs. well analysis approach. Finally, some advice and guiding on necessary prerequisites for launching a field SRA will be shared.\u0000 The methodology followed previous advices, with the added element that all wells were categorized depending on similarities in well design. Furthermore, a number of local finite element analyses for a specified systematic set of variations in input parameters have been performed by relevant equipment manufacturers to calculate the fatigue stress at critical hot spots (load-to-stress curves).\u0000 Similar actions on loads had to be performed. A comprehensive set of global load analyses for each of the different rigs that have been operating on the field where needed to assess the cyclic fatigue loads from historical operations on each well. Finally, global and local analysis results were then gathered, and used as input to the SRA combined with a response surface technique.\u0000 The additional effort for making the underlying global and local analyses covering all wells, and not only a single well, is limited for a given type of wellhead system. The field results now provide the operator with an improved basis for planning of future operations on the field, and enables optimization of the drilling plan and utilization of rigs throughout the varying environmental conditions for different seasons of the year and different operations, while managing the associated risk.","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":"130453291","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}

{"title":"Fatigue Performance of High Strength and Large Diameter Mooring Chain in Seawater","authors":"Yan-Hui Zhang, P. Smedley","doi":"10.1115/omae2019-95984","DOIUrl":"https://doi.org/10.1115/omae2019-95984","url":null,"abstract":"\u0000 Fatigue design recommendations provided by API RP 2SK, ISO 19901-7 and DNVGL-OS-E301 for studless chain links are based on data of steel grades R3 and R4 and mainly of link diameter of 76mm. Mooring systems utilising larger diameter links and higher strength steels (e.g. grade R5) are now in operation. Consequently, industry expressed a need for fatigue test data in seawater of higher steel grade and larger diameter chain to confirm whether the existing fatigue design guidance is applicable. A joint industry project (JIP) was launched by TWI to investigate fatigue performance of high strength and large diameter mooring chain in free corrosion seawater. A test rig was designed and manufactured which was capable of testing studless mooring chain links up to 127mm link diameter under tension-tension loading. Twenty-three full-scale fatigue tests were conducted on high strength steel grades (R4 and R5) and larger diameter chains (76mm and 127mm) generating 72 link failures. Magnetic particle inspections (MPI) were carried out to characterise the location of cracking, crack size and crack growth rate. This paper describes the results obtained in the JIP.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"8 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":"122100107","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}

{"title":"Structural Safety Assessment of Marine Operations From a Long-Term Perspective: A Case Study of Offshore Wind Turbine Blade Installation","authors":"A. Verma, Z. Gao, Zhiyu Jiang, Z. Ren, N. P. Vedvik","doi":"10.1115/omae2019-96686","DOIUrl":"https://doi.org/10.1115/omae2019-96686","url":null,"abstract":"\u0000 A marine operation is a complex non-routine activity of limited duration carried out in offshore environment. Due to safety reasons, these operations are normally performed within specific sea state limits, which are derived from numerical modelling and analysis of hazardous events. In view of the uncertainties in the assessment of structural responses under stochastic environmental conditions, these limiting curves correspond to a target structural failure probability recommended in offshore standards (for example, 10−4 per operation as specified by DNV-GL). However, one of the main limitations is that these curves do not reflect site-specific safety assessment. The current paper presents a novel methodology for assessing the structural safety level of marine operations from a long-term perspective. The methodology includes estimation of extreme response distribution under all possible operational sea states (i.e. the operational domain under the limiting sea states) for a given offshore site and is compared to the response limit to obtain an average failure probability. A case study is also presented for a blade root mating process onto preassembled hub using a jack-up crane vessel and risk of impact between root and hub is considered critical. Global time-domain simulations are performed using multibody dynamics, and extreme value distributions for impact velocities are derived for different wind-wave conditions. The allowable impact velocity between the blade root and the hub is determined by an explicit finite element analysis of the damage at the blade root. Finally, the average failure probabilities considering the operational domain are obtained for four different European offshore sites and are compared to the target level of structural failure probability considered for the limiting sea states.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"134 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":"123903659","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}

{"title":"A Sensitivity Study for Operational Availability of Offshore Wind Energy Assets","authors":"J. Chiachío-Ruano, Mahé Hermile, A. Kolios","doi":"10.1115/omae2019-96323","DOIUrl":"https://doi.org/10.1115/omae2019-96323","url":null,"abstract":"\u0000 The rampant growth of offshore wind energy in Europe and overseas is calling for advanced operation and maintenance simulation tools for optimal infrastructure asset management. The operational downtimes due to random failures, repair times or adverse weather conditions, greatly reduce the availability of the wind farm and therefore increase the Levelised Cost of Energy of this important source of renewable energy. This paper presents a sensitivity analysis to explore the factors influencing the most the operational availability of an offshore wind farm over a particular geographical area. The analysis is carried out using a newly developed open-access tool for operation and maintenance simulation named as “OpenO&M”. The failure rates of wind turbine components and the weather safety allowable limits for maintenance vessels emerge as critical parameters for wind farm availability, specially in remote areas.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"42 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":"117283397","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}

{"title":"Study on Residual Strength of Egg-Shaped Pressure Shell With Local Damage","authors":"S. Yuan, He Gao","doi":"10.1115/omae2019-95456","DOIUrl":"https://doi.org/10.1115/omae2019-95456","url":null,"abstract":"\u0000 The eggshell is a multifocal, rotary thin-walled structure that satisfies the positive Gaussian curve. The eggshell meets the dome principle and requires no additional rib support to achieve sufficient strength and stability with minimal material. Some scholars have applied this bionic prototype to the pressure-resistant shell, which proves that it has good comprehensive performance. However, there is less in-depth discussion of the buckling characteristics of this new pressure-resistant shell yet. In this paper, the dangerous situation of collision, reefing and other accidents during the use of deep submersibles is considered, the residual strength of the shell with partial damage is studied, which is of practical engineering significance. Firstly, the ABUQUS finite element software is used to calculate the buckling of the egg-shaped pressure shell with local deformation, and the influence of local deformation on the buckling mode and ultimate bearing capacity of the pressure shell is analyzed. Secondly, by designing the pressure-resistant shells with different concave amplitudes and recessed positions, the influence of the pressure-resistant shell on the stability of the pressure-resistant shell is analyzed. Finally, according to the calculation results, the sensitivity law of different concave positions to the concave amplitude is summarized, and the beneficial engineering opinions are given.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"7 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":"127486940","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}

{"title":"Fatigue Behavior of Large, Rolled-After Heat-Treatment and Hot-Dip Galvanized HT Bolts","authors":"J. Unglaub, K. Thiele","doi":"10.1115/omae2019-96808","DOIUrl":"https://doi.org/10.1115/omae2019-96808","url":null,"abstract":"\u0000 As a subproject in the framework of the DFG Research Training Group “Graduiertenkolleg 2075 - Modelling the constitutive evolution of building materials and structures with respect to aging” (GRK 2075), the fatigue behavior of rolled-after heat-treatment and hot-dipped galvanized HT-bolts is examined. Results of fatigue tests of M48x255 10.9 and M36x235 10.9 HT-bolts from different states of manufacturing processes (rolled-after heat-treatment, rolled-after heat-treatment and hot-dip galvanized) will be presented and discussed. If rolled-after heat-treatment HT-bolts are hot-dip galvanized, the fatigue life is significantly reduced. However, it is beyond the fatigue life of rolled-before heat-treatment HT-bolts and hot-dip galvanized HT-bolts.","PeriodicalId":314553,"journal":{"name":"Volume 3: Structures, Safety, and Reliability","volume":"98 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":"126052012","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}