A system designed for a rigid and flexible pipe laying purposes is presented in the paper.Mathematical and numerical models are developed by using the rigid finite element method（RFEM）.The RFEM is an efficient solut...A system designed for a rigid and flexible pipe laying purposes is presented in the paper.Mathematical and numerical models are developed by using the rigid finite element method（RFEM）.The RFEM is an efficient solution in the time domain.Static and dynamic problems related to pipe installation are solved by taking the advantage of simple interpretation and implementation of the method.Large deformations of the pipe during spooling and when it is reeled out at sea are considered.A material model implemented is used to take into consideration nonlinear material properties.In particular,the full elasto-plastic material characteristics with hardening and Bauschinger effect are included.Dynamic analyses are performed and the results attached in this work demonstrates how the sea conditions influence the machinery and pipeline,assuming a passive reel drive system. The influence of several other operational parameters on dynamic loads is verified.An active system,implemented as a part of the mathematical model,improves the system performance.Some results are presented as well.展开更多
In the present study, we simulated the reel-lay installation process of deepwater steel catenary risers（SCRs） using the finite element method and proposed multiaxial fatigue analysis for reeled SCRs. The reel-lay me...In the present study, we simulated the reel-lay installation process of deepwater steel catenary risers（SCRs） using the finite element method and proposed multiaxial fatigue analysis for reeled SCRs. The reel-lay method is one of the most efficient and economical pipeline installation methods. However, material properties of reeled risers may change, especially in the weld zone, which can affect the fatigue performance. Applying finite element analysis（FEA）, we simulated an installation load history through the reel, aligner, and straightener and analyzed the property variations. The impact of weld defects during the installation process, lack of penetration and lack of fusion, was also discussed. Based on the FEA results, we used the Brown-Miller criterion combined with the critical plane approach to predict the fatigue life of reeled and non-reeled models. The results indicated that a weld defect has a significant influence on the material properties of a riser, and the reel-lay method can significantly reduce the fatigue life of SCRs. The analysis conclusion can help designers understand the mechanical performance of welds during reel-lay installation.展开更多
Currently, there are various reels on the market regarding the type of mechanism, which achieves the winding and unwinding of the line. The designers have the purpose of obtaining a linear transmission function, by me...Currently, there are various reels on the market regarding the type of mechanism, which achieves the winding and unwinding of the line. The designers have the purpose of obtaining a linear transmission function, by means of a simple and small-sized mechanism. However, the present solutions are not satisfactory because of large deviations from linearity of the transmission function and complexity of mechanical schema. A novel solution for the reel spool mechanism is proposed. Its kinematic schema and synthesis method are described. The kinematic schema of the chosen mechanism is based on a noncircular gear in series with a scotch-yoke mechanism. The yoke is driven by a stud fixed on the driving noncircular gear. The drawbacks of other models regarding the effects occurring at the ends of the spool are eliminated through achieving an appropriate transmission function of the spool. The linear function approximation with curved end-arches appropriately computed to ensure mathematical continuity is very good. The experimental results on the mechanism model validate the theoretical approach. The developed mechanism solution is recorded under a reel spool mechanism patent.展开更多
This paper discusses how to achieve good quality high-speed reeling, pointing out that for high-speed reeling, in the first place, miss feeding time should be shortened considerably, and that the supplyof correct end ...This paper discusses how to achieve good quality high-speed reeling, pointing out that for high-speed reeling, in the first place, miss feeding time should be shortened considerably, and that the supplyof correct end cocoons and the end feeding capacity should also meet certain requirements. The miss feed-ing time of most domestic and foreign models of high-speed reeling machines is about 5 seconds. In theSFD- 507 High-Speed Automatic Reeling Machine. the mechanoelectrical size control device (PatentNO. 8620786) can reduce miss feeding time down to 2. 5 seconds, thus ensuring satisfactory raw silkevenness in high-speed reeling. Furthermore, effective measures are taken to raise the end feeding ca-pacity and the supply of correct end cocoons. Therefore, this machine is able to meet in all respects thedemands of good quality high-speed reeling. Wider adoption of it will bring chinese reeling industry intoa new stage of high-speed reeling.展开更多
In terms of reel-lay installation in deep water, studies on the pipeline during the process of tensioning have been completed based on theories of risk and reliability analysis and Ergonomics. Qualitative risk results...In terms of reel-lay installation in deep water, studies on the pipeline during the process of tensioning have been completed based on theories of risk and reliability analysis and Ergonomics. Qualitative risk results, including minimum cut sets, structural importance and probability expression of system failure, are obtained from fault tree analysis. Also, quantitative risk results, mainly consisting of failure probability and reliability index of pipeline plastic deformation, are worked out through Monte Carlo simulation. Simultaneously, scientific suggestions based on Ergonomics are provided. Conclusions drawn from this paper can, to some extent, provide certain references for reel-lay installation in deep water.展开更多
Crops are prone to lodging with the decline of stem moisture and the intervention of other factors in the mature harvest period,such as garlic,which is difficult to harvest mechanically.To solve this problem,the plant...Crops are prone to lodging with the decline of stem moisture and the intervention of other factors in the mature harvest period,such as garlic,which is difficult to harvest mechanically.To solve this problem,the plant-correcting reel for harvesting lodging garlic plants,bumped and deformed with plants many times to pull and lift them into a conveyor,is proposed in this study.We analyzed the motion trajectory equation and key influencing factors of the reel and defined the lifting and plant-correcting stages as three processes of contact,stirring and release.For example,the contact deformation model and system energy equations were established in the contact process.Besides,in the stirring process,the garlic plant-correcting conditions were established through the dynamic simulation test analysis of garlic seedling trajectories and the deflection model of garlic stem was constructed.Furthermore,in the release process,the expressions of rubber bars rotation and garlic plant offset bending curvature were constructed and the optimal number and distribution form of bars were determined.Meanwhile,the mechanism and key operating parameters of the auxiliary lifting mechanism of the divider were established.Through the single-factor test,the influence of reel speed,forward speed and reel height on the success feeding rate was analyzed under different bars distribution forms;Through multi-factor experiments,the interaction contour map of various factors was constructed.When reel speed,forward speed and reel height were 3 rad/s,3.5 m/s,and 540 mm,the feeding success rate was 98.73%.The optimization factors were tested and verified,which met the operational requirements of a high feeding success rate and low loss rate of garlic harvest.This study combines laboratory virtual as well as field experiments and analyzes of trajectory of bars,contact deformation and deflection model of garlic plant,and reel rotation and garlic plant offset bending curvature to solve the problem of garlic lodging mechanized harvest and yield reduction.展开更多
基金supported by the Polish Ministry of Science and Higher Education(N N502 464934)
文摘A system designed for a rigid and flexible pipe laying purposes is presented in the paper.Mathematical and numerical models are developed by using the rigid finite element method（RFEM）.The RFEM is an efficient solution in the time domain.Static and dynamic problems related to pipe installation are solved by taking the advantage of simple interpretation and implementation of the method.Large deformations of the pipe during spooling and when it is reeled out at sea are considered.A material model implemented is used to take into consideration nonlinear material properties.In particular,the full elasto-plastic material characteristics with hardening and Bauschinger effect are included.Dynamic analyses are performed and the results attached in this work demonstrates how the sea conditions influence the machinery and pipeline,assuming a passive reel drive system. The influence of several other operational parameters on dynamic loads is verified.An active system,implemented as a part of the mathematical model,improves the system performance.Some results are presented as well.
基金supported by the National Key Natural Science Foundation of China(Grant No.50739004)the National Natural Science Foundation of China(Grant Nos.51009093 and 51379005)
文摘In the present study, we simulated the reel-lay installation process of deepwater steel catenary risers（SCRs） using the finite element method and proposed multiaxial fatigue analysis for reeled SCRs. The reel-lay method is one of the most efficient and economical pipeline installation methods. However, material properties of reeled risers may change, especially in the weld zone, which can affect the fatigue performance. Applying finite element analysis（FEA）, we simulated an installation load history through the reel, aligner, and straightener and analyzed the property variations. The impact of weld defects during the installation process, lack of penetration and lack of fusion, was also discussed. Based on the FEA results, we used the Brown-Miller criterion combined with the critical plane approach to predict the fatigue life of reeled and non-reeled models. The results indicated that a weld defect has a significant influence on the material properties of a riser, and the reel-lay method can significantly reduce the fatigue life of SCRs. The analysis conclusion can help designers understand the mechanical performance of welds during reel-lay installation.
基金Supported by an industrial commission developed at TU Dresden and think MOTION project,under the Information and Communication Technologies Policy Support ProgrammeArea:CIP-ICT-PSP.2009.2.3–Digital Libraries:European Digital Library Digitizing Content for Europeana(01.06.2010–31.05.2013)
文摘Currently, there are various reels on the market regarding the type of mechanism, which achieves the winding and unwinding of the line. The designers have the purpose of obtaining a linear transmission function, by means of a simple and small-sized mechanism. However, the present solutions are not satisfactory because of large deviations from linearity of the transmission function and complexity of mechanical schema. A novel solution for the reel spool mechanism is proposed. Its kinematic schema and synthesis method are described. The kinematic schema of the chosen mechanism is based on a noncircular gear in series with a scotch-yoke mechanism. The yoke is driven by a stud fixed on the driving noncircular gear. The drawbacks of other models regarding the effects occurring at the ends of the spool are eliminated through achieving an appropriate transmission function of the spool. The linear function approximation with curved end-arches appropriately computed to ensure mathematical continuity is very good. The experimental results on the mechanism model validate the theoretical approach. The developed mechanism solution is recorded under a reel spool mechanism patent.
文摘This paper discusses how to achieve good quality high-speed reeling, pointing out that for high-speed reeling, in the first place, miss feeding time should be shortened considerably, and that the supplyof correct end cocoons and the end feeding capacity should also meet certain requirements. The miss feed-ing time of most domestic and foreign models of high-speed reeling machines is about 5 seconds. In theSFD- 507 High-Speed Automatic Reeling Machine. the mechanoelectrical size control device (PatentNO. 8620786) can reduce miss feeding time down to 2. 5 seconds, thus ensuring satisfactory raw silkevenness in high-speed reeling. Furthermore, effective measures are taken to raise the end feeding ca-pacity and the supply of correct end cocoons. Therefore, this machine is able to meet in all respects thedemands of good quality high-speed reeling. Wider adoption of it will bring chinese reeling industry intoa new stage of high-speed reeling.
文摘In terms of reel-lay installation in deep water, studies on the pipeline during the process of tensioning have been completed based on theories of risk and reliability analysis and Ergonomics. Qualitative risk results, including minimum cut sets, structural importance and probability expression of system failure, are obtained from fault tree analysis. Also, quantitative risk results, mainly consisting of failure probability and reliability index of pipeline plastic deformation, are worked out through Monte Carlo simulation. Simultaneously, scientific suggestions based on Ergonomics are provided. Conclusions drawn from this paper can, to some extent, provide certain references for reel-lay installation in deep water.
基金China Agriculture Research System of MOF and MARA(CARS-24-D-01)National Key R&D Program of China(Grant No.2023YFD2001200)Shandong Province focuses on supporting the introduction of urgently needed and scarce talent projects in the region.
文摘Crops are prone to lodging with the decline of stem moisture and the intervention of other factors in the mature harvest period,such as garlic,which is difficult to harvest mechanically.To solve this problem,the plant-correcting reel for harvesting lodging garlic plants,bumped and deformed with plants many times to pull and lift them into a conveyor,is proposed in this study.We analyzed the motion trajectory equation and key influencing factors of the reel and defined the lifting and plant-correcting stages as three processes of contact,stirring and release.For example,the contact deformation model and system energy equations were established in the contact process.Besides,in the stirring process,the garlic plant-correcting conditions were established through the dynamic simulation test analysis of garlic seedling trajectories and the deflection model of garlic stem was constructed.Furthermore,in the release process,the expressions of rubber bars rotation and garlic plant offset bending curvature were constructed and the optimal number and distribution form of bars were determined.Meanwhile,the mechanism and key operating parameters of the auxiliary lifting mechanism of the divider were established.Through the single-factor test,the influence of reel speed,forward speed and reel height on the success feeding rate was analyzed under different bars distribution forms;Through multi-factor experiments,the interaction contour map of various factors was constructed.When reel speed,forward speed and reel height were 3 rad/s,3.5 m/s,and 540 mm,the feeding success rate was 98.73%.The optimization factors were tested and verified,which met the operational requirements of a high feeding success rate and low loss rate of garlic harvest.This study combines laboratory virtual as well as field experiments and analyzes of trajectory of bars,contact deformation and deflection model of garlic plant,and reel rotation and garlic plant offset bending curvature to solve the problem of garlic lodging mechanized harvest and yield reduction.
