Pub Date : 2024-06-01DOI: 10.17736/ijope.2024.jc907
Ken-ichi Fujita, Harumi Yashiro
To establish a structural risk assessment method for offshore floating wind turbines, this study presents an evaluation method of damage probability of pontoon-type floating offshore wind turbines subjected to random wind and wave loads. The hydroelastic response of the structure to random loads is analyzed using a stationary random vibration theory. The damage probability of the structure is evaluated using a first-order reliability method. Numerical examples show a variety of hydroelastic responses and the damage probability of structures for different wind speeds and directions during operation and shutdown.
{"title":"Damage Probability Evaluation of Pontoon-type Floating Offshore Wind Turbines Subjected to Both Random Wind and Wave Loads","authors":"Ken-ichi Fujita, Harumi Yashiro","doi":"10.17736/ijope.2024.jc907","DOIUrl":"https://doi.org/10.17736/ijope.2024.jc907","url":null,"abstract":"To establish a structural risk assessment method for offshore floating wind turbines, this study presents an evaluation method of damage probability of pontoon-type floating offshore wind turbines subjected to random wind and wave loads. The hydroelastic response of the structure to random loads is analyzed using a stationary random vibration theory. The damage probability of the structure is evaluated using a first-order reliability method. Numerical examples show a variety of hydroelastic responses and the damage probability of structures for different wind speeds and directions during operation and shutdown.","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141404184","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}
Pub Date : 2024-06-01DOI: 10.17736/ijope.2024.su04
R. Suzuki, Michio Ueno
This paper presents a prediction method for the steady wave longitudinal and lateral forces and yaw moment acting on ship maneuvering with a forward speed, lateral drift, and yaw rate in short waves. Specifically, the existing formula that focuses on wave diffraction is modified in terms of the wave amplitude near ships and the finite draught of ships. The effects of each modification are discussed based on predictions for a very large crude carrier and container ship. Moreover, the prediction method with and without each modification is validated by comparing the prediction results with published experimental data.
{"title":"A Prediction Method for Steady Wave Forces and Moment Acting on Ship Maneuvering in Short Waves","authors":"R. Suzuki, Michio Ueno","doi":"10.17736/ijope.2024.su04","DOIUrl":"https://doi.org/10.17736/ijope.2024.su04","url":null,"abstract":"This paper presents a prediction method for the steady wave longitudinal and lateral forces and yaw moment acting on ship maneuvering with a forward speed, lateral drift, and yaw rate in short waves. Specifically, the existing formula that focuses on wave diffraction is modified in terms of the wave amplitude near ships and the finite draught of ships. The effects of each modification are discussed based on predictions for a very large crude carrier and container ship. Moreover, the prediction method with and without each modification is validated by comparing the prediction results with published experimental data.","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141399030","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}
Pub Date : 2024-06-01DOI: 10.17736/ijope.2023.ak60
Naoto Naito, Tatsuya Matsuda, Kinya Miura
Taking into consideration the prevalence of rocking vibrations in structures featuring rectangular cross-sections, we introduced an approach for precise determination of the inherent frequencies of such structures. To validate the effectiveness of our proposed method for identifying natural frequencies, we carried out an extensive experimental campaign using a scaled model of a caisson-type breakwater. The study aimed to assess the feasibility of our method in evaluating the structural integrity of the breakwater under varying degrees of scouring. Our findings underscored the potential of microtremor measurements in detecting the advancement of scouring in the caisson-type breakwater.
{"title":"Assessing Caisson Breakwater Integrity Against Scour Through Ground-Structure System Vibrations","authors":"Naoto Naito, Tatsuya Matsuda, Kinya Miura","doi":"10.17736/ijope.2023.ak60","DOIUrl":"https://doi.org/10.17736/ijope.2023.ak60","url":null,"abstract":"Taking into consideration the prevalence of rocking vibrations in structures featuring rectangular cross-sections, we introduced an approach for precise determination of the inherent frequencies of such structures. To validate the effectiveness of our proposed method for identifying natural frequencies, we carried out an extensive experimental campaign using a scaled model of a caisson-type breakwater. The study aimed to assess the feasibility of our method in evaluating the structural integrity of the breakwater under varying degrees of scouring. Our findings underscored the potential of microtremor measurements in detecting the advancement of scouring in the caisson-type breakwater.","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141408497","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}
Pub Date : 2024-06-01DOI: 10.17736/ijope.2024.ty14
Martin Eriksson, Magnus Nyberg, Michael Andersen, Jesper Tychsen, Jørgen Nielsen
Nonlinear finite element analysis is a powerful tool for the determination of ultimate capacities of steel components. To produce reliable predictions with high confidence of structural strength, it is of fundamental importance that nonlinear finite element analyses are based on a validated methodology. This paper presents a validated methodology with statistically calibrated failure (fracture) criteria providing either a characteristic or mean level of capacity/response for the detailed finite element assessment of strength of typical structural details forming a part of offshore structures. More than 60 large-scale physical tests representing plated details/joints as well as tubular joints form the basis of the developed methodology.
{"title":"Validated Methodology for Assessment of Welded Steel Structures by Nonlinear Finite Element Analysis","authors":"Martin Eriksson, Magnus Nyberg, Michael Andersen, Jesper Tychsen, Jørgen Nielsen","doi":"10.17736/ijope.2024.ty14","DOIUrl":"https://doi.org/10.17736/ijope.2024.ty14","url":null,"abstract":"Nonlinear finite element analysis is a powerful tool for the determination of ultimate capacities of steel components. To produce reliable predictions with high confidence of structural strength, it is of fundamental importance that nonlinear finite element analyses are based on a validated methodology. This paper presents a validated methodology with statistically calibrated failure (fracture) criteria providing either a characteristic or mean level of capacity/response for the detailed finite element assessment of strength of typical structural details forming a part of offshore structures. More than 60 large-scale physical tests representing plated details/joints as well as tubular joints form the basis of the developed methodology.","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141403140","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}
Pub Date : 2024-06-01DOI: 10.17736/ijope.2024.jc928
R. Glienke, F. Kalkowsky, A. Hobbacher, A. Holch, Benjamin Ripsch, Hans-Peter Günther, R. Kersten, Knuth-Michael Henkel
Butt welds are one of the most common structural details in wind turbine steel towers. In this paper, results from fatigue tests on butt welds in the as-welded and grit-blasted conditions are presented. In addition, finite element analyses were performed using the effective notch stress and the crack propagation approaches. By using macroscopic measurements and three-dimensional scan, the notch effect of the weld seam was considered. These results were compared with results from fatigue tests. On the basis of a successful alignment between simulation and experiment, the possibility to discuss the fatigue resistance influencing variables from the seam geometry is presented.
{"title":"Improving the Fatigue Strength of Butt Welds in the As-Welded and Grit-Blasted Condition for Steel Towers of Wind Turbines","authors":"R. Glienke, F. Kalkowsky, A. Hobbacher, A. Holch, Benjamin Ripsch, Hans-Peter Günther, R. Kersten, Knuth-Michael Henkel","doi":"10.17736/ijope.2024.jc928","DOIUrl":"https://doi.org/10.17736/ijope.2024.jc928","url":null,"abstract":"Butt welds are one of the most common structural details in wind turbine steel towers. In this paper, results from fatigue tests on butt welds in the as-welded and grit-blasted conditions are presented. In addition, finite element analyses were performed using the effective notch stress and the crack propagation approaches. By using macroscopic measurements and three-dimensional scan, the notch effect of the weld seam was considered. These results were compared with results from fatigue tests. On the basis of a successful alignment between simulation and experiment, the possibility to discuss the fatigue resistance influencing variables from the seam geometry is presented.","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141398922","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}
Pub Date : 2024-06-01DOI: 10.17736/ijope.2024.jc929
Toshifumi Fujiwara
The navigation situation and its results from National Maritime Research Institute cruising autonomous underwater vehicles (AUVs) with formation control are presented in this paper. The AUV navigation is assumed by a control on leader-follower formation applicable to various underwater measurements. The navigation order as dynamic waypoints for AUV communication is modeled by a graph theory while being easily modified to suit the purpose. In this paper, the effectiveness and impact of the waypoint indication intervals from a leader AUV to a follower AUV are clarified in assuming to conduct undersea exploration based on the navigational performance of an actual AUV.
{"title":"Leader-Follower Formation Control Characteristics with Dynamic Way Point on Cruising AUVs","authors":"Toshifumi Fujiwara","doi":"10.17736/ijope.2024.jc929","DOIUrl":"https://doi.org/10.17736/ijope.2024.jc929","url":null,"abstract":"The navigation situation and its results from National Maritime Research Institute cruising autonomous underwater vehicles (AUVs) with formation control are presented in this paper. The AUV navigation is assumed by a control on leader-follower formation applicable to various underwater measurements. The navigation order as dynamic waypoints for AUV communication is modeled by a graph theory while being easily modified to suit the purpose. In this paper, the effectiveness and impact of the waypoint indication intervals from a leader AUV to a follower AUV are clarified in assuming to conduct undersea exploration based on the navigational performance of an actual AUV.","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141389896","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}
Pub Date : 2024-06-01DOI: 10.17736/ijope.2024.sv11
Jaehak Lee, Yonghwan Kim, Jaehak Lee, Yangjun Ahn
.
.
{"title":"Prediction of Wave-Induced Nonlinear Ship Motions Based on an IRF-LSTM Hybrid Approach","authors":"Jaehak Lee, Yonghwan Kim, Jaehak Lee, Yangjun Ahn","doi":"10.17736/ijope.2024.sv11","DOIUrl":"https://doi.org/10.17736/ijope.2024.sv11","url":null,"abstract":".","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141399865","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}
Pub Date : 2024-06-01DOI: 10.17736/ijope.2023.cl24
Christian Windt, Nils Goseberg, Stefan Schimmels, M. Kudella, Ranjith khumar Shanmugasundaram, Henrik Rusche, V. Vanjakula, F. Adam, Dawid Majewski, Krystyna Kazimierowicz-Frankowska, Michal Pietrzkiewicz, VS Ozgür Kirca, B. Sumer
Wave-induced liquefaction results in significant seabed dynamics and can lead to a complete loss of the bearing capacity of the soil. With the increasing use of marine space for energy harnessing, geotechnical challenges move into focus during the development and planning of such installations. To date, a lack of comprehensive modelling tools for wave-induced liquefaction around marine structures has been observed. This paper documents the efforts in the framework of the NuLI-MAS project to provide such a modelling tool. In particular, this paper presents a numerical implementation of the hydro-geotechnical processes together with a detailed overview of the calibration and validation strategy employing small-and large-scale experimental data, respectively.
{"title":"Liquefaction Around Marine Structures: Development of a Numerical Modelling Framework in OpenFOAM®","authors":"Christian Windt, Nils Goseberg, Stefan Schimmels, M. Kudella, Ranjith khumar Shanmugasundaram, Henrik Rusche, V. Vanjakula, F. Adam, Dawid Majewski, Krystyna Kazimierowicz-Frankowska, Michal Pietrzkiewicz, VS Ozgür Kirca, B. Sumer","doi":"10.17736/ijope.2023.cl24","DOIUrl":"https://doi.org/10.17736/ijope.2023.cl24","url":null,"abstract":"Wave-induced liquefaction results in significant seabed dynamics and can lead to a complete loss of the bearing capacity of the soil. With the increasing use of marine space for energy harnessing, geotechnical challenges move into focus during the development and planning of such installations. To date, a lack of comprehensive modelling tools for wave-induced liquefaction around marine structures has been observed. This paper documents the efforts in the framework of the NuLI-MAS project to provide such a modelling tool. In particular, this paper presents a numerical implementation of the hydro-geotechnical processes together with a detailed overview of the calibration and validation strategy employing small-and large-scale experimental data, respectively.","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141402477","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}
Pub Date : 2024-06-01DOI: 10.17736/ijope.2024.jc923
Han-bing Luo, Liya Zhang, Fupeng Liu, Licheng Qin, Xiaodong Bai
.
.
{"title":"Numerical Analysis on Coupling Dynamic Response of Twin Barge-Topside Floatover During Load Transfer Stage in Beam Waves","authors":"Han-bing Luo, Liya Zhang, Fupeng Liu, Licheng Qin, Xiaodong Bai","doi":"10.17736/ijope.2024.jc923","DOIUrl":"https://doi.org/10.17736/ijope.2024.jc923","url":null,"abstract":".","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141392928","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}
The rapid sampling technology for marine gas hydrate (RSTGH) is proposed to improve the efficiency of hydrate resource evaluation. RSTGH mainly consists of a hydraulic reverse circulation sampling (HRCS) apparatus and mud cooling sys-tem. It can be verified from lab tests that 800 L/min of mud circulation at 24 (cid:158) C could be cooled to − 6 (cid:48) 1 (cid:158) C within 45 min. Furthermore, the experiment of HRCS was carried out offshore, and the average core recovery rate was 86% in unconsoli-dated formation. Through simulation, the temperature of the mud outlet was stable at − 1 (cid:48) 21 (cid:158) C after circulating for 9 h in a 1,200 m well, with the temperature of the mud inlet at − 5 (cid:158) C and a flow rate of 800 L/min. It provides a new method for the rapid evaluation of marine hydrate resources.
{"title":"The Theoretical and Experimental Research on Rapid Sampling Technology for Marine Gas Hydrate","authors":"Xiaoyang Li, Yingying Tian, Shiyu Zhang, Ming Zhao, Kuan Li, Xin Zhang","doi":"10.17736/ijope.2024.jc909","DOIUrl":"https://doi.org/10.17736/ijope.2024.jc909","url":null,"abstract":"The rapid sampling technology for marine gas hydrate (RSTGH) is proposed to improve the efficiency of hydrate resource evaluation. RSTGH mainly consists of a hydraulic reverse circulation sampling (HRCS) apparatus and mud cooling sys-tem. It can be verified from lab tests that 800 L/min of mud circulation at 24 (cid:158) C could be cooled to − 6 (cid:48) 1 (cid:158) C within 45 min. Furthermore, the experiment of HRCS was carried out offshore, and the average core recovery rate was 86% in unconsoli-dated formation. Through simulation, the temperature of the mud outlet was stable at − 1 (cid:48) 21 (cid:158) C after circulating for 9 h in a 1,200 m well, with the temperature of the mud inlet at − 5 (cid:158) C and a flow rate of 800 L/min. It provides a new method for the rapid evaluation of marine hydrate resources.","PeriodicalId":503139,"journal":{"name":"International Journal of Offshore and Polar Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141392480","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：