C. Ohl, Chris Shorrock, G. Cameron, Holger Zipfel, Sven Harlos
After drought conditions were experienced across New Zealand in 2019, Watercare determined that the 175 million litres per day (MLD) upgrade to the Waikato River to Redoubt Reservoir (R2R) project should be increased in capacity by including a 50MLD Water Treatment Plant (WTP) on the Waikato River at a remote location 60km south of Auckland, New Zealand. Required for urgent drought mitigation, the WTP was designed and commissioned within 12 months, enabling water delivery to Auckland by southern hemisphere Winter 2021. As a conventional pump station could not have been constructed at this remote site within the timeframe, a Floating Pump Station was developed utilising modular Linkflote pontoons to support the equipment, gangways for services and access and tubular piles for restraint. With principal issues of constructability and short programme, the superstructure design incorporated a steel spreader frame to distribute relatively high, concentrated loads over the Linkflote pontoon system.
{"title":"60MLD Floating Pump Station, Waikato River, New Zealand","authors":"C. Ohl, Chris Shorrock, G. Cameron, Holger Zipfel, Sven Harlos","doi":"10.1680/jmaen.2022.012","DOIUrl":"https://doi.org/10.1680/jmaen.2022.012","url":null,"abstract":"After drought conditions were experienced across New Zealand in 2019, Watercare determined that the 175 million litres per day (MLD) upgrade to the Waikato River to Redoubt Reservoir (R2R) project should be increased in capacity by including a 50MLD Water Treatment Plant (WTP) on the Waikato River at a remote location 60km south of Auckland, New Zealand. Required for urgent drought mitigation, the WTP was designed and commissioned within 12 months, enabling water delivery to Auckland by southern hemisphere Winter 2021. As a conventional pump station could not have been constructed at this remote site within the timeframe, a Floating Pump Station was developed utilising modular Linkflote pontoons to support the equipment, gangways for services and access and tubular piles for restraint. With principal issues of constructability and short programme, the superstructure design incorporated a steel spreader frame to distribute relatively high, concentrated loads over the Linkflote pontoon system.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"63 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87139871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohd Ishtiyak, A. Sarkar, T. Fazeres-Ferradosa, P. Rosa-Santos, F. Taveira-Pinto, Rui Figueiredo, X. Romão
Monopiles are the Industry's first choice today to support an Offshore Wind Turbine (OWT) due to the complexities associated with fabrication, transportation, and installation of various foundation solutions. These are, however, considered suitable for water depths up to around 30 to 35 m, beyond which these become massive and complex to handle. Increasing monopiles’ application range without making them too large by adopting some suitable means may significantly impact the rapid growth of OWTs at intermediate water depths (∼50 m), where existing solutions like jackets or concrete gravity foundations involve large capital expenditure. In this paper, a novel approach of utilizing pre-tensioned tethers along with a 6.0 m diameter monopile has been explored for 50 m water depth. Under extreme load case, the stress ratio has been noted to be reduced from 1.17 to 0.44 when the pre-tensioned tethers are used. Similarly, it is found that by adjusting parameters associated with the proposed concept, the fatigue damage can be brought down from a very high value to 0.63 or less. Thus the results show that the proposed approach can open new avenue to bring competitiveness to the cost of offshore wind energy at the intermediate water depths.
{"title":"Performance of a novel concept of a monopile adapted with pre-tensioned tethers for intermediate waters","authors":"Mohd Ishtiyak, A. Sarkar, T. Fazeres-Ferradosa, P. Rosa-Santos, F. Taveira-Pinto, Rui Figueiredo, X. Romão","doi":"10.1680/jmaen.2023.001","DOIUrl":"https://doi.org/10.1680/jmaen.2023.001","url":null,"abstract":"Monopiles are the Industry's first choice today to support an Offshore Wind Turbine (OWT) due to the complexities associated with fabrication, transportation, and installation of various foundation solutions. These are, however, considered suitable for water depths up to around 30 to 35 m, beyond which these become massive and complex to handle. Increasing monopiles’ application range without making them too large by adopting some suitable means may significantly impact the rapid growth of OWTs at intermediate water depths (∼50 m), where existing solutions like jackets or concrete gravity foundations involve large capital expenditure. In this paper, a novel approach of utilizing pre-tensioned tethers along with a 6.0 m diameter monopile has been explored for 50 m water depth. Under extreme load case, the stress ratio has been noted to be reduced from 1.17 to 0.44 when the pre-tensioned tethers are used. Similarly, it is found that by adjusting parameters associated with the proposed concept, the fatigue damage can be brought down from a very high value to 0.63 or less. Thus the results show that the proposed approach can open new avenue to bring competitiveness to the cost of offshore wind energy at the intermediate water depths.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"45 6 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77200247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Offshore Wind Turbines (OWT) are usually constructed on a large diameter monopile. These foundations are subjected to lateral loads and overturning moments due to wind and wave action. The lateral loads from a violent wind and waves are cyclic. In this paper, an attempt has been made to examine the influence of embedded length on monopile behaviour using finite element analysis (Plaxis 3D). The centrifuge test carried out on a monopile embedded in sandy soil was used to validate the constituent model. The numerical studies were performed on a 6m diameter monopile by varying the load amplitude and embedded length ratios (L/D = 4, 5, and 6). The monopile was subjected to both one-way and two-way symmetric lateral cyclic loading with an amplitude of 30%, 40%, and 50% of the monotonic ultimate capacity of the pile. The effect of embedded lengths and the load amplitudes on the accumulated displacements and the cyclic stiffness were studied. From the study, it is found that the rate of accumulated displacement increases by a factor of 0.3 to 0.7 when the load amplitude increased from 30% to 50%. Also, the load amplitude was observed to cause a linear increase in the accumulated displacements. The slope of attenuation value was found to be higher for an increase in the L/D ratio from 4 to 5 as compared to 5 to 6.
{"title":"Finite element analysis of a monopile under one-way and two-way lateral cyclic loading","authors":"D. Nigitha, Deendayal Rathod, K. Krishnanunni","doi":"10.1680/jmaen.2021.027","DOIUrl":"https://doi.org/10.1680/jmaen.2021.027","url":null,"abstract":"Offshore Wind Turbines (OWT) are usually constructed on a large diameter monopile. These foundations are subjected to lateral loads and overturning moments due to wind and wave action. The lateral loads from a violent wind and waves are cyclic. In this paper, an attempt has been made to examine the influence of embedded length on monopile behaviour using finite element analysis (Plaxis 3D). The centrifuge test carried out on a monopile embedded in sandy soil was used to validate the constituent model. The numerical studies were performed on a 6m diameter monopile by varying the load amplitude and embedded length ratios (L/D = 4, 5, and 6). The monopile was subjected to both one-way and two-way symmetric lateral cyclic loading with an amplitude of 30%, 40%, and 50% of the monotonic ultimate capacity of the pile. The effect of embedded lengths and the load amplitudes on the accumulated displacements and the cyclic stiffness were studied. From the study, it is found that the rate of accumulated displacement increases by a factor of 0.3 to 0.7 when the load amplitude increased from 30% to 50%. Also, the load amplitude was observed to cause a linear increase in the accumulated displacements. The slope of attenuation value was found to be higher for an increase in the L/D ratio from 4 to 5 as compared to 5 to 6.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"14 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72396757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.1680/jmaen.2023.176.2.46
T. Fazeres-Ferradosa, D. Pavlou, S. Siriwardane, N. Adasooriya
{"title":"Preface: Offshore Structures and Subsea Technologies","authors":"T. Fazeres-Ferradosa, D. Pavlou, S. Siriwardane, N. Adasooriya","doi":"10.1680/jmaen.2023.176.2.46","DOIUrl":"https://doi.org/10.1680/jmaen.2023.176.2.46","url":null,"abstract":"","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"67 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83256389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Hsu, Yuzhi Wei, Chung-Hong Lee, Long Van Hoang, N. Huynh
This paper aims to carry out the risk assessment of work safety in container dry ports (CDPs) by adopting a continuous risk matrix (CRM) based on a Fuzzy Analytic Hierarchy Process (AHP). The originality of this paper consists of (1) identifying risk factors (RFs) for work safety at CDPs, (2) adopting the fuzzy AHP approach to estimate the likelihood and consequence weights of RFs, (3) developing CRM to evaluate the risk level of work safety in CDPs. For the empirical study, CDPs in Vietnam were surveyed to verify the research model. The proposed continuous risk matrix can contribute as a reference for theoretical methodologies in risk assessment research. At the same time, the empirical study can provide practical information for dry port managers to improve their performance in work safety.
{"title":"Risk assessment model of work safety in container dry ports: The adoption of the continuous risk matrix and Fuzzy AHP","authors":"W. Hsu, Yuzhi Wei, Chung-Hong Lee, Long Van Hoang, N. Huynh","doi":"10.1680/jmaen.2022.006","DOIUrl":"https://doi.org/10.1680/jmaen.2022.006","url":null,"abstract":"This paper aims to carry out the risk assessment of work safety in container dry ports (CDPs) by adopting a continuous risk matrix (CRM) based on a Fuzzy Analytic Hierarchy Process (AHP). The originality of this paper consists of (1) identifying risk factors (RFs) for work safety at CDPs, (2) adopting the fuzzy AHP approach to estimate the likelihood and consequence weights of RFs, (3) developing CRM to evaluate the risk level of work safety in CDPs. For the empirical study, CDPs in Vietnam were surveyed to verify the research model. The proposed continuous risk matrix can contribute as a reference for theoretical methodologies in risk assessment research. At the same time, the empirical study can provide practical information for dry port managers to improve their performance in work safety.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"71 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74823875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical experiments provide the best representation of foundation behaviour in any environmental conditions offshore, however they are very costly, especially since the on-site conditions vary. Hence it is not a cost-effective approach. On the other hand, numerical modelling is relatively cheaper, but requires long computation time and a high level of expertise to perform a successful numerical calculation. The main objective of this paper is to develop a simple and fast response analysis that requires less computational time and expertise. First, an analytical model is developed to study the dynamic behaviour of the pile by extending the beam on an elastic foundation. Second, the analytical results are verified by using the finite element software Abaqus. Finally, a parametric study is performed with the established numerical calculation model to investigate the modal shapes of the pile model, limit states of the OWT and pile capacity for different loading conditions and aspect ratios. The proposed analytical model demonstrated a degree of error less than 10%, indicating great reliability and practical application. The parametric results indicate that the OWT is more likely to fail by yielding than buckling and the soil resistance at the pile periphery is highly affected by the aspect ratio.
{"title":"Dynamic response of offshore wind turbine monopile foundation under wind-wave loads","authors":"Godfred F. Akwaa, Meng Gao","doi":"10.1680/jmaen.2022.023","DOIUrl":"https://doi.org/10.1680/jmaen.2022.023","url":null,"abstract":"Physical experiments provide the best representation of foundation behaviour in any environmental conditions offshore, however they are very costly, especially since the on-site conditions vary. Hence it is not a cost-effective approach. On the other hand, numerical modelling is relatively cheaper, but requires long computation time and a high level of expertise to perform a successful numerical calculation. The main objective of this paper is to develop a simple and fast response analysis that requires less computational time and expertise. First, an analytical model is developed to study the dynamic behaviour of the pile by extending the beam on an elastic foundation. Second, the analytical results are verified by using the finite element software Abaqus. Finally, a parametric study is performed with the established numerical calculation model to investigate the modal shapes of the pile model, limit states of the OWT and pile capacity for different loading conditions and aspect ratios. The proposed analytical model demonstrated a degree of error less than 10%, indicating great reliability and practical application. The parametric results indicate that the OWT is more likely to fail by yielding than buckling and the soil resistance at the pile periphery is highly affected by the aspect ratio.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"26 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73913277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arash Vatani, Jafar Jafari-Asl, Sima Ohadi, N. S. Hamzehkolaei, Sanaz Afzali Ahmadabadi, J. Correia
This study proposes a hybrid random forest-based subset simulation (RFSS) method for probabilistic assessment of the scour around pile groups under waves. In the RFSS, random forest (RF) is employed to replace the true limit state function, and it is updated based on the design samples in the first and last levels of subset simulation (SS) method. In this regard, 127 laboratory datasets collected from the literature were used to modeling. First, an existing equation for predicting the scour depth around piles was modified by using a metaheuristic approach. The performance of the modified equation was compared with four equations and two artificial intelligence (AI) models. The comparisons demonstrated that modified equation more accuracy than existing formulas and previous AI-based models. Then, a probabilistic model based on the RFSS was developed by considering the modified formula as the limit state function of scour depth. Solving two numerical, one hydraulic engineering, and scour of piles group problems, validate the robustness and accuracy of the developed structural reliability method. Results showed that the novel proposed RFSS is a robust and efficient method for solving high-dimensional real-world problems. Furthermore, compared to the Monte Carlo Simulation (MCS), the RFSS enable to estimate the reliability index with fewer computational cost and same accuracy. The function call number of RFSS was obtained 160 at the first example, 100 at the second example, 100 at the hydraulic example, and 150 at the scour of piles example.
{"title":"An efficient random forest-based subset simulation method for reliability analysis of the marine structure piles subject to scour","authors":"Arash Vatani, Jafar Jafari-Asl, Sima Ohadi, N. S. Hamzehkolaei, Sanaz Afzali Ahmadabadi, J. Correia","doi":"10.1680/jmaen.2022.020","DOIUrl":"https://doi.org/10.1680/jmaen.2022.020","url":null,"abstract":"This study proposes a hybrid random forest-based subset simulation (RFSS) method for probabilistic assessment of the scour around pile groups under waves. In the RFSS, random forest (RF) is employed to replace the true limit state function, and it is updated based on the design samples in the first and last levels of subset simulation (SS) method. In this regard, 127 laboratory datasets collected from the literature were used to modeling. First, an existing equation for predicting the scour depth around piles was modified by using a metaheuristic approach. The performance of the modified equation was compared with four equations and two artificial intelligence (AI) models. The comparisons demonstrated that modified equation more accuracy than existing formulas and previous AI-based models. Then, a probabilistic model based on the RFSS was developed by considering the modified formula as the limit state function of scour depth. Solving two numerical, one hydraulic engineering, and scour of piles group problems, validate the robustness and accuracy of the developed structural reliability method. Results showed that the novel proposed RFSS is a robust and efficient method for solving high-dimensional real-world problems. Furthermore, compared to the Monte Carlo Simulation (MCS), the RFSS enable to estimate the reliability index with fewer computational cost and same accuracy. The function call number of RFSS was obtained 160 at the first example, 100 at the second example, 100 at the hydraulic example, and 150 at the scour of piles example.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"10 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72709018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present paper deals with state of the art in Structural Health Monitoring (SHM) methods in offshore and marine structures. Most of the SHM methods have been developed for onshore infrastructures. Few works are available to implement SHM technologies in offshore and marine structures. This paper aims to fill this gap and highlight the challenges in implementing SHM methods in offshore and marine structures. The present work categorizes the available techniques for establishing SHM models in oil rigs, offshore wind turbine structures, subsea systems, vessels, pipelines etc. Besides, the capabilities of the proposed ideas in the recent publications are classified into three main categories: a) the Model-Based, b) the Vibration-Based, and c) the Digital Twin methods. Recently developed novel signal processing and machine learning algorithms have been reviewed, and their abilities have been discussed. Developed methods in Vision-Based and Population-Based approaches have also been presented and discussed. The present paper aims to provide a guideline for selecting and establishing SHM in offshore and marine structures.
{"title":"State of the art in structural health monitoring of offshore and marine structures","authors":"H. Pezeshki, H. Adeli, D. Pavlou, S. Siriwardane","doi":"10.1680/jmaen.2022.027","DOIUrl":"https://doi.org/10.1680/jmaen.2022.027","url":null,"abstract":"The present paper deals with state of the art in Structural Health Monitoring (SHM) methods in offshore and marine structures. Most of the SHM methods have been developed for onshore infrastructures. Few works are available to implement SHM technologies in offshore and marine structures. This paper aims to fill this gap and highlight the challenges in implementing SHM methods in offshore and marine structures. The present work categorizes the available techniques for establishing SHM models in oil rigs, offshore wind turbine structures, subsea systems, vessels, pipelines etc. Besides, the capabilities of the proposed ideas in the recent publications are classified into three main categories: a) the Model-Based, b) the Vibration-Based, and c) the Digital Twin methods. Recently developed novel signal processing and machine learning algorithms have been reviewed, and their abilities have been discussed. Developed methods in Vision-Based and Population-Based approaches have also been presented and discussed. The present paper aims to provide a guideline for selecting and establishing SHM in offshore and marine structures.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"85 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86679177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It is well known that the installation loads during offshore pipeline installation are usually higher than the operation ones. FRP materials for offshore pipeline applications seems to be very promising due to their high strength, light weight, and excellent corrosion and fatigue resistance. However, during S-lay installation high bending stresses that may cause material failure or buckling take place. Due to the anisotropic nature of the multi-layered FRP pipelines, the permissible bending curvature is difficult to be estimated. Few published works have proposed the framework for bending stress calculations and have provided complex equations that is not convenient to be used. In the present work, an open numerical code in Mathematica® is offered for the first time. Numerical results for S-lay installation of representative pipelines are provided and commended.
{"title":"Computer-aided design of offshore S-lay FRP pipeline installation: An open code Part I: Bending stresses","authors":"D. Pavlou","doi":"10.1680/jmaen.2022.025","DOIUrl":"https://doi.org/10.1680/jmaen.2022.025","url":null,"abstract":"It is well known that the installation loads during offshore pipeline installation are usually higher than the operation ones. FRP materials for offshore pipeline applications seems to be very promising due to their high strength, light weight, and excellent corrosion and fatigue resistance. However, during S-lay installation high bending stresses that may cause material failure or buckling take place. Due to the anisotropic nature of the multi-layered FRP pipelines, the permissible bending curvature is difficult to be estimated. Few published works have proposed the framework for bending stress calculations and have provided complex equations that is not convenient to be used. In the present work, an open numerical code in Mathematica® is offered for the first time. Numerical results for S-lay installation of representative pipelines are provided and commended.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"9 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75380067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dynamic response of offshore pipelines and risers under cross flow (e.g., ocean currents, vessel motion, etc) has successfully been analysed. Although the pipelines are used for fluid transportation, no sufficient attention has been paid in the dynamic instability under axial flow. In the present work, axial flow-induced instability mechanisms of offshore pipelines and risers are investigated. To this end, the interaction of the axial flow forces of a fluid element with the forces of the corresponding pipe element during pipeline flexural motion is analysed. Interpretation of the terms of the motion equation is provided and analogies with the model of dynamic buckling of a Euler beam are detected. Transfer Matrices are originally developed for the dynamic control of pipelines under axial flow. The critical values of the flow velocity causing dynamic instability and the corresponding axial flow-induced buckling modes are determined. Implementation of the method to a representative case study is provided and discussed.
{"title":"Dynamic instability mechanisms of offshore pipelines and risers","authors":"D. Pavlou","doi":"10.1680/jmaen.2022.026","DOIUrl":"https://doi.org/10.1680/jmaen.2022.026","url":null,"abstract":"Dynamic response of offshore pipelines and risers under cross flow (e.g., ocean currents, vessel motion, etc) has successfully been analysed. Although the pipelines are used for fluid transportation, no sufficient attention has been paid in the dynamic instability under axial flow. In the present work, axial flow-induced instability mechanisms of offshore pipelines and risers are investigated. To this end, the interaction of the axial flow forces of a fluid element with the forces of the corresponding pipe element during pipeline flexural motion is analysed. Interpretation of the terms of the motion equation is provided and analogies with the model of dynamic buckling of a Euler beam are detected. Transfer Matrices are originally developed for the dynamic control of pipelines under axial flow. The critical values of the flow velocity causing dynamic instability and the corresponding axial flow-induced buckling modes are determined. Implementation of the method to a representative case study is provided and discussed.","PeriodicalId":54575,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Maritime Engineering","volume":"01 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85958981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","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：