Volume 2B: Structures, Safety, and Reliability最新文献_第2页

Numerical Simulation of Elastic Deformation Based on Peridynamic Differential Operator 基于周动力微分算子的弹性变形数值模拟

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19015

Yumeng Hu, F. Liu, G. Feng, Dongxu Zhang

{"title":"Numerical Simulation of Elastic Deformation Based on Peridynamic Differential Operator","authors":"Yumeng Hu, F. Liu, G. Feng, Dongxu Zhang","doi":"10.1115/omae2020-19015","DOIUrl":"https://doi.org/10.1115/omae2020-19015","url":null,"abstract":"\u0000 The methodology of Peridynamics has been proposed for years and widely used in various engineering fields. The evolution of this theory is always in process, and two major branches appears, namely bond-based and state-based peridynamic method. Recently, a novel concept, peridynamic differential operator, was proposed and adopted in simulation of Newtonian fluid and analysis of structure strength. Just like the intrinsic idea in peridynamic theory, this new operator could convert the partial differential into its integral form so that it would enable the numerical differentiation through integration and avoid difficulties such as discontinuities or singularities encountered in the simulation. Also, unlike the traditional method that the higher order partial differential items are derived from the lower ones, peridynamic differential operator could easily provide differential items with any desired order thus it makes calculation process more efficient and convenient. In this study, the accuracy of peridynamic differential operator is tested by comparing with a given analytical formula. Then, this operator is embedded into the framework of Galerkin method and adopted for elastic deformation analysis in 2D case. The results are compared with those obtained from finite element method and its efficiency and feasibility are verified.","PeriodicalId":191387,"journal":{"name":"Volume 2B: Structures, Safety, and Reliability","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125586752","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

Load-Carrying Characteristics of Foam Core and Joint Geometry in Sandwich Structures 夹层结构泡沫芯的承载特性与节点几何

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18055

J. Ringsberg

{"title":"Load-Carrying Characteristics of Foam Core and Joint Geometry in Sandwich Structures","authors":"J. Ringsberg","doi":"10.1115/omae2020-18055","DOIUrl":"https://doi.org/10.1115/omae2020-18055","url":null,"abstract":"\u0000 Composite sandwich ships have laminated joints that contribute to a significant part of the ship’s weight. Their construction requires an extensive number of man-hours. There is great potential for weight and production-time-reduction through alternative joint designs. According to class rules, one is not allowed to benefit from the load-carrying capability of the core, i.e. the strength characteristics of the core shall be disregarded and geometry at the joint location is disregarded as well. The objective of the current investigation was to investigate the possibility of constructing a joint where the load-carrying capability of the foam core is accounted for, leading to a reduction in weight and production time. One specific joint in a 23 m composite sandwich catamaran was selected for study — a side wall-wet deck T-joint. This joint is considered to be crucial for the structural integrity of the current vessel. A global finite element (FE) model of the catamaran was designed and analysed in ANSYS. The loads and boundary conditions were applied to the global model according to DNV GL’s HSLC rules. Two local FE models of the joints (2D and 3D) were utilized for a parametric analysis with respect to structure response (stress concentrations and compliance with failure and fracture criteria). Finally, the results and conclusions from the study show the possibilities and advantages of incorporating the foam core material as a load-carrying member in joint design without compromising safety.","PeriodicalId":191387,"journal":{"name":"Volume 2B: Structures, Safety, and Reliability","volume":"301 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131762966","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

Calculation of Fatigue Capacity for a Subsea Wellhead Connector 海底井口接头疲劳承载力计算

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19329

S. H. Hashemizadeh, Venu Sunkavilli, T. Hørte, P. Osen

{"title":"Calculation of Fatigue Capacity for a Subsea Wellhead Connector","authors":"S. H. Hashemizadeh, Venu Sunkavilli, T. Hørte, P. Osen","doi":"10.1115/omae2020-19329","DOIUrl":"https://doi.org/10.1115/omae2020-19329","url":null,"abstract":"\u0000 In the 2019 version of DNVGL-RP-C203 Fatigue Design of Offshore Steel Structures, significantly improved methods have been added on how to establish M-N curves representing the fatigue resistance of preloaded connectors subject to cyclic bending. The M-N curve parameters are typically provided by the manufacturer and used by operators and drilling contractors for calculating the wellhead fatigue life for planned drilling operations.\u0000 DNVGL-RP-C203 provides specific advice on how to establish design M-N curves based on analysis, and the augmentation by possible testing, where testing may grant more favorable M-N curves and thus extended fatigue life for any given case.\u0000 The paper provides background and introduction to the improved analysis methodology and relevant S-N curves for high-strength steels for wellhead systems, given in the 2019 version of the DNVGL-RP-C203. It includes a worked example in order to demonstrate the detailed use of the method, applied on a Baker Hughes preloaded BOP connector, connected to a 27” wellhead mandrel. This example describes the finite element model set up, FE model mesh refinement in hot-spots, the application of cyclic loads, extraction of hot-spot cyclic stresses, and the establishment of the M-N curve for the connector.","PeriodicalId":191387,"journal":{"name":"Volume 2B: Structures, Safety, and Reliability","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134130808","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

Offshore Drilling: Extending the Weather Window for Operations by Optimal Use of Simulations and Probabilistic Machine Learning 海上钻井:通过优化使用模拟和概率机器学习来延长作业的天气窗口

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19119

S. Eldevik, Stian Sætre, E. Katla, A. Aardal

{"title":"Offshore Drilling: Extending the Weather Window for Operations by Optimal Use of Simulations and Probabilistic Machine Learning","authors":"S. Eldevik, Stian Sætre, E. Katla, A. Aardal","doi":"10.1115/omae2020-19119","DOIUrl":"https://doi.org/10.1115/omae2020-19119","url":null,"abstract":"\u0000 Operators of offshore floating drilling units have limited time to decide on whether a drilling operation can continue as planned or if it needs to be postponed or aborted due to oncoming bad weather. With day-rates of several hundred thousand USD, small delays in the original schedule might amass to considerable costs. On the other hand, pushing the limits of the load capacity of the riser-stack and wellhead may compromise the integrity of the well itself, and such a failure is not an option.\u0000 Advanced simulation techniques may reduce uncertainty about how different weather scenarios influence the system’s integrity, and thus increase the acceptable weather window considerably. However, real-time simulations are often not feasible and the stochastic behavior of wave-loads make it difficult to simulate all relevant weather scenarios prior to the operation.\u0000 This paper outlines and demonstrates an approach which utilizes probabilistic machine learning techniques to effectively reduce uncertainty. More specifically we use Gaussian process regression to enable fast approximation of the relevant structural response from complex simulations. The probabilistic nature of the method adds the benefit of an estimated uncertainty in the prediction which can be utilized to optimize how the initial set of relevant simulation scenarios should be selected, and to predict real-time estimates of the utilization and its uncertainty when combined with current weather forecasts.\u0000 This enables operators to have an up-to-date forecast of the system’s utilization, as well as sufficient time to trigger additional scenario-specific simulation(s) to reduce the uncertainty of the current situation. As a result, it reduces unnecessary conservatism and gives clear decision support for critical situations.","PeriodicalId":191387,"journal":{"name":"Volume 2B: Structures, Safety, and Reliability","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123916107","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

Collapse Analysis of Ship Hull Girder Using Hydro-Elastoplastic Beam Model: Part 2 基于水弹塑性梁模型的船体梁倒塌分析:第2部分

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19201

Han Htoo Htoo Ko, Akira Tatsumi, K. Iijima, M. Fujikubo

引用次数: 0

Model Experimental Research of Ship Section on Structural Ultimate Strength 船舶截面结构极限强度模型试验研究

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18397

Chen Xianyin, Zeng Wenyuan, Li Cong, Wang Wei

引用次数: 0

Ultimate Strength and Collapse Behavior of Ring-Stiffened Cylindrical Shells Under External Pressure With Shell Buckling or Stiffener Torsional Buckling 外压下环加筋圆柱壳屈曲或加筋扭转屈曲的极限强度和破坏行为

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-19295

Daisuke Shiomitsu, D. Yanagihara

{"title":"Ultimate Strength and Collapse Behavior of Ring-Stiffened Cylindrical Shells Under External Pressure With Shell Buckling or Stiffener Torsional Buckling","authors":"Daisuke Shiomitsu, D. Yanagihara","doi":"10.1115/omae2020-19295","DOIUrl":"https://doi.org/10.1115/omae2020-19295","url":null,"abstract":"\u0000 A series of ultimate strength analyses of ring-stiffened cylindrical shells with various dimensions and scantlings is carried out applying the nonlinear finite element method. The detailed buckling/plastic collapse behavior including the influence of initial deflection applied in the ultimate strength analyses is investigated. In most past studies, detailed classification of collapse modes and investigation of the influence of the initial deflection mode have not been sufficiently conducted. In this study, firstly the ultimate strength analyses of 288 cases varying the dimensions of the ring-stiffened cylindrical shell and the attachment direction of the stiffeners, inside or outside, are performed. From the results, the collapse modes are classified into five modes, which are stiffener-torsional buckling collapse (localized deformation mode and mode to keep strength after the ultimate strength), shell buckling collapse (localized deformation mode and mode with kinking lines), and combined collapse of the buckling modes. A slenderness ratio is proposed using elastic buckling strength and pressure when the circumferential stress reaches the yield stress, and the possibility of estimating the ultimate strength is indicated.","PeriodicalId":191387,"journal":{"name":"Volume 2B: Structures, Safety, and Reliability","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129846272","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

Structural Reliability Analysis Method for Assessing the Fatigue Capacity of Subsea Wellhead Connectors 海底井口连接件疲劳能力评估的结构可靠性分析方法

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18498

T. Hørte, L. Reinås, A. Wormsen, A. Aardal, P. Gustafsson

{"title":"Structural Reliability Analysis Method for Assessing the Fatigue Capacity of Subsea Wellhead Connectors","authors":"T. Hørte, L. Reinås, A. Wormsen, A. Aardal, P. Gustafsson","doi":"10.1115/omae2020-18498","DOIUrl":"https://doi.org/10.1115/omae2020-18498","url":null,"abstract":"\u0000 Subsea Wellheads are the male part of an 18 3/4” bore connector used for connecting subsea components such as drilling BOP, XT or Workover systems equipped with a female counterpart — a wellhead connector. Subsea wellheads have an external locking profile for engaging a preloaded wellhead connector with matching internal profile. As such connection is made subsea, a metal-to-metal sealing is obtained, and a structural conduit is formed. The details of the subsea wellhead profile are specified by the wellhead user and the standardized H4 hub has a widespread use.\u0000 In terms of well integrity, the wellhead connector is a barrier element during both well construction (drilling) activities and life of field (production). Due to the nature of subsea drilling operations, a wellhead connector will be subjected to external loads. Fatigue and plastic collapse due to overload are therefore two potential failure modes. These two failure modes are due to the cyclic nature of the loads and the potential for accidental and extreme single loads respectively. The safe load the wellhead connector can sustain without failure can be established by deterministic structural capacity methods.\u0000 This paper outlines how a generic and probabilistic engineering method; Structural Reliability Analysis, can be applied to a subsea wellhead connector to estimate the probability of fatigue failure (PoF). As the wellhead connector is a mechanism consisting of a plurality of parts the load effect from cyclic external loads is influenced by uncertainty in friction, geometry and pre-load. Further, there is a inter dependence between these parameters that complicates the problem. In addition to these uncertainties, uncertainties in the fatigue loading itself (from rig and riser) is also accounted for.\u0000 This paper presents results from applications of Structural Reliability Analysis (SRA) to a wellhead connector and provides experiences and learnings from this case work.","PeriodicalId":191387,"journal":{"name":"Volume 2B: Structures, Safety, and Reliability","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128329202","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

Numerical and Experimental Study on Ultimate Strength of Stiffened Column Under Axial Compression 轴压下加筋柱极限强度的数值与试验研究

Volume 2B: Structures, Safety, and Reliability Pub Date : 2020-08-03 DOI: 10.1115/omae2020-18340

H. Mei, De-yu Wang, Qi Wan

{"title":"Numerical and Experimental Study on Ultimate Strength of Stiffened Column Under Axial Compression","authors":"H. Mei, De-yu Wang, Qi Wan","doi":"10.1115/omae2020-18340","DOIUrl":"https://doi.org/10.1115/omae2020-18340","url":null,"abstract":"\u0000 Six specimens with one Tee-bar stiffener and its attached plating were tested under axial compression to investigate the ultimate strength. The specimens have one longitudinal span and the simply supported boundary conditions at the end edge of loading were produced based on a horizontal test fixture. The initial geometrical imperfections were measured and tensile tests of high tensile steel used in the specimens with different thickness were conducted. The results calculated by FE analysis with true stress-strain curves, average measured thickness and measured initial geometrical deformation could reach a good agreement with experimental results. The ultimate strength calculated with elastic/perfectly plastic curve is approximately 10% larger than that with true stress-strain curve. The reason is that the proportional limit stress of material is significantly lower than 0.2% proof stress for the high strength steel used in specimens. And the occurrence of buckling is earlier than the time that the material enters into plastic stage. As a result, the ultimate strength assessed with elastic/perfectly plastic curve doesn’t always the lowest result and it should be adopted carefully.","PeriodicalId":191387,"journal":{"name":"Volume 2B: Structures, Safety, and Reliability","volume":"320 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133510527","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