Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal...Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal with BHOR, and then its global strength in manifold cases was analyzed, along with the use of a three-dimensional nonlinear time domain finite element program. So the max bending stress, max circumferential stress, and max axial stress in the BHOR bundle main section (BMS) were obtained, and the values of these three stresses in each riser were obtained through the "stress distribution method". Finally, the Max Von Mises stress in each riser was given and a check was made whether or not they met the demand. This paper provides a reference for strength analysis of the bundled hybrid offset riser and some other bundled pipelines.展开更多
Global strength is a significant item for floating production storage and offloading(FPSO) design, and steel weight plays an important role in the building costs of FPSO. It is the main task to consider and combine th...Global strength is a significant item for floating production storage and offloading(FPSO) design, and steel weight plays an important role in the building costs of FPSO. It is the main task to consider and combine these two aspects by optimizing hull dimensions. There are many optional methods for the global strength analysis. A common method is to use the ABS FPSO Eagle software to analyze the global strength including the rule check and direct strength analysis. And the same method can be adopted for the FPSO hull optimization by changing the depth. After calculation and optimization, the results are compared and analyzed. The results can be used as a reference for the future design or quotation purpose.展开更多
Distinguished Guests Ladies and Gentlemen,Friends,It’s a great pleasure to meet all of you in the autumn of the beautiful city of Chongqing to open a window of dialogue and to have an exchange of ideas.First,on behal...Distinguished Guests Ladies and Gentlemen,Friends,It’s a great pleasure to meet all of you in the autumn of the beautiful city of Chongqing to open a window of dialogue and to have an exchange of ideas.First,on behalf of the Communist Party of China(CPC)and the Chinese government,I would like to extend my warm welcome to you and my congratulations on the opening of'The CPC in Dialogue with the World 2016'.Not long ago,the G20展开更多
The Paraconsistent Many-Valued Similarity (PMVS) method for multi-attribute decision making will be incomplete as a decision model if it is not extended to the realm of group decision-making. Therefore, in this articl...The Paraconsistent Many-Valued Similarity (PMVS) method for multi-attribute decision making will be incomplete as a decision model if it is not extended to the realm of group decision-making. Therefore, in this article, our primary objective is to show how the paraconsistent many-valued similarity method can be used to solve group decision-making problems involving choice making or ranking of a finite set of decision alternatives. Moreover, since weights are very important parameters in multi-attribute decision-making, we have introduced the Borda rule to calculate the weights of experts and that of every criterion under consideration. To demonstrate how the proposed method works, a numerical example on energy sources of an economy from the points of view of a group of experts is investigated. Further, we compare the results of this new approach with that of fuzzy TOPSIS group decision-making method to illustrate the robustness and effectiveness of the former.展开更多
Offshore steel structures are a common investment in oil and gas industries operating in shallow to medium depth seas.These structures have become increasingly popular since the mid-19th century,with a typical design ...Offshore steel structures are a common investment in oil and gas industries operating in shallow to medium depth seas.These structures have become increasingly popular since the mid-19th century,with a typical design life of 30-50 years.Despite their popularity,the structural integrity of existing offshore structures remains a controversial topic.Environmental loads and material degradation have been identified as significant factors that can compromise the structural integrity of offshore structures.To address this issue,this study aims to investigate the reserved strength capacity of a selected offshore structure located in the Malaysian Seas.The study will explore the effect of oceanographic data,variations in vertical load,and corrosion on the structure’s main members.To determine the impact of each variable on the reserved strength ratio(RSR)of the structure,several pushover analyses were conducted with different variables.Previous literature has shown little or no relationship between seawater wave height,gravity loads,and corrosion allowance on submerged steel members and the RSR of offshore structures.However,this study aims tofill this gap in knowledge by examining these variables’effects on the RSR of offshore structures.The study’sfindings indicate that even a slight increase in wave height can significantly impact the structure’s RSR due to the increase in lateral loading,potentially leading to severe damage to structural components and the foundation model.Additionally,gravity loads had an adverse effect on the RSR of the structure when more than double the vertical load was added.Corrosion allowance was also found to impact the RSR,particularly when assuming significant wall thickness corrosion in primary members.Overall,thefindings of this study have important implications for the design and maintenance of offshore structures.The results suggest that engineers and operators should pay close attention to the potential impacts of environmental loads,such as wave height and gravity loads,and material degradation,such as corrosion allowance,on the structural integrity of offshore structures.This information can be used to optimize the design and maintenance of offshore structures,leading to safer and more efficient operations.展开更多
为掌握桁架平台的连续与间断对全船总纵强度的影响,采用MSC_Patran软件,通过全船有限元分析(Finite Element Analysis,FEA)方法,分别对桁架平台整体性连续布置和将桁架平台间断为多个独立桁架平台布置2种情况下船体的总纵强度进行计算,...为掌握桁架平台的连续与间断对全船总纵强度的影响,采用MSC_Patran软件,通过全船有限元分析(Finite Element Analysis,FEA)方法,分别对桁架平台整体性连续布置和将桁架平台间断为多个独立桁架平台布置2种情况下船体的总纵强度进行计算,得出船体主要纵向连续构件的应力分布情况,以及该桁架平台对船体挠度的影响程度,并进行分析对比。结果发现,平台整体性连续布置相比间断布置对船体及桁架平台本身的总纵强度有更好的加强作用。展开更多
超大型海上浮式结构物(very large floating structures,VLFS)由多个模块组成,单模块结构强度是研究超大型海上浮式结构物强度的基础,因此,有必要对超大型浮体单模块在典型波浪载荷下进行强度分析.首先根据挪威船级社(DNV)海上浮式结构...超大型海上浮式结构物(very large floating structures,VLFS)由多个模块组成,单模块结构强度是研究超大型海上浮式结构物强度的基础,因此,有必要对超大型浮体单模块在典型波浪载荷下进行强度分析.首先根据挪威船级社(DNV)海上浮式结构物强度分析的相关规范,考虑该超大型海上浮式结构物单模块下浮体横向设置的特点,选取了纵向分离、纵向扭转、横向剪切和垂向弯曲4种典型波浪载荷工况;然后采用SESAM有限元分析软件,对波浪载荷进行长期预报;最后基于有限元直接计算方法对超大型海上浮式结构物单模块在4种典型工况下的强度进行计算,分析得到结构整体应力水平分布均匀,但存在上箱体和立柱连接处部位、下浮体和立柱连接处、撑杆几何尺寸变化3处高应力区的相关结论,为超大型海上浮式结构物的结构设计提供了相关理论依据.展开更多
基金Supported by the National Natural Science Foundation of China (Grant No.51009033)
文摘Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal with BHOR, and then its global strength in manifold cases was analyzed, along with the use of a three-dimensional nonlinear time domain finite element program. So the max bending stress, max circumferential stress, and max axial stress in the BHOR bundle main section (BMS) were obtained, and the values of these three stresses in each riser were obtained through the "stress distribution method". Finally, the Max Von Mises stress in each riser was given and a check was made whether or not they met the demand. This paper provides a reference for strength analysis of the bundled hybrid offset riser and some other bundled pipelines.
基金the sponsors of this project: American Bureau of Shipping
文摘Global strength is a significant item for floating production storage and offloading(FPSO) design, and steel weight plays an important role in the building costs of FPSO. It is the main task to consider and combine these two aspects by optimizing hull dimensions. There are many optional methods for the global strength analysis. A common method is to use the ABS FPSO Eagle software to analyze the global strength including the rule check and direct strength analysis. And the same method can be adopted for the FPSO hull optimization by changing the depth. After calculation and optimization, the results are compared and analyzed. The results can be used as a reference for the future design or quotation purpose.
文摘Distinguished Guests Ladies and Gentlemen,Friends,It’s a great pleasure to meet all of you in the autumn of the beautiful city of Chongqing to open a window of dialogue and to have an exchange of ideas.First,on behalf of the Communist Party of China(CPC)and the Chinese government,I would like to extend my warm welcome to you and my congratulations on the opening of'The CPC in Dialogue with the World 2016'.Not long ago,the G20
文摘The Paraconsistent Many-Valued Similarity (PMVS) method for multi-attribute decision making will be incomplete as a decision model if it is not extended to the realm of group decision-making. Therefore, in this article, our primary objective is to show how the paraconsistent many-valued similarity method can be used to solve group decision-making problems involving choice making or ranking of a finite set of decision alternatives. Moreover, since weights are very important parameters in multi-attribute decision-making, we have introduced the Borda rule to calculate the weights of experts and that of every criterion under consideration. To demonstrate how the proposed method works, a numerical example on energy sources of an economy from the points of view of a group of experts is investigated. Further, we compare the results of this new approach with that of fuzzy TOPSIS group decision-making method to illustrate the robustness and effectiveness of the former.
文摘Offshore steel structures are a common investment in oil and gas industries operating in shallow to medium depth seas.These structures have become increasingly popular since the mid-19th century,with a typical design life of 30-50 years.Despite their popularity,the structural integrity of existing offshore structures remains a controversial topic.Environmental loads and material degradation have been identified as significant factors that can compromise the structural integrity of offshore structures.To address this issue,this study aims to investigate the reserved strength capacity of a selected offshore structure located in the Malaysian Seas.The study will explore the effect of oceanographic data,variations in vertical load,and corrosion on the structure’s main members.To determine the impact of each variable on the reserved strength ratio(RSR)of the structure,several pushover analyses were conducted with different variables.Previous literature has shown little or no relationship between seawater wave height,gravity loads,and corrosion allowance on submerged steel members and the RSR of offshore structures.However,this study aims tofill this gap in knowledge by examining these variables’effects on the RSR of offshore structures.The study’sfindings indicate that even a slight increase in wave height can significantly impact the structure’s RSR due to the increase in lateral loading,potentially leading to severe damage to structural components and the foundation model.Additionally,gravity loads had an adverse effect on the RSR of the structure when more than double the vertical load was added.Corrosion allowance was also found to impact the RSR,particularly when assuming significant wall thickness corrosion in primary members.Overall,thefindings of this study have important implications for the design and maintenance of offshore structures.The results suggest that engineers and operators should pay close attention to the potential impacts of environmental loads,such as wave height and gravity loads,and material degradation,such as corrosion allowance,on the structural integrity of offshore structures.This information can be used to optimize the design and maintenance of offshore structures,leading to safer and more efficient operations.
文摘为掌握桁架平台的连续与间断对全船总纵强度的影响,采用MSC_Patran软件,通过全船有限元分析(Finite Element Analysis,FEA)方法,分别对桁架平台整体性连续布置和将桁架平台间断为多个独立桁架平台布置2种情况下船体的总纵强度进行计算,得出船体主要纵向连续构件的应力分布情况,以及该桁架平台对船体挠度的影响程度,并进行分析对比。结果发现,平台整体性连续布置相比间断布置对船体及桁架平台本身的总纵强度有更好的加强作用。
文摘超大型海上浮式结构物(very large floating structures,VLFS)由多个模块组成,单模块结构强度是研究超大型海上浮式结构物强度的基础,因此,有必要对超大型浮体单模块在典型波浪载荷下进行强度分析.首先根据挪威船级社(DNV)海上浮式结构物强度分析的相关规范,考虑该超大型海上浮式结构物单模块下浮体横向设置的特点,选取了纵向分离、纵向扭转、横向剪切和垂向弯曲4种典型波浪载荷工况;然后采用SESAM有限元分析软件,对波浪载荷进行长期预报;最后基于有限元直接计算方法对超大型海上浮式结构物单模块在4种典型工况下的强度进行计算,分析得到结构整体应力水平分布均匀,但存在上箱体和立柱连接处部位、下浮体和立柱连接处、撑杆几何尺寸变化3处高应力区的相关结论,为超大型海上浮式结构物的结构设计提供了相关理论依据.
