In this paper,the multi-body coupled dynamic characteristics of a semisubmersible platform and an HYSY 229 barge were investigated.First,coupled hydrodynamic analysis of the HYSY 229 barge and the semisubmersible plat...In this paper,the multi-body coupled dynamic characteristics of a semisubmersible platform and an HYSY 229 barge were investigated.First,coupled hydrodynamic analysis of the HYSY 229 barge and the semisubmersible platform was performed.Relevant hydrodynamic parameters were obtained using the retardation function method of three-dimensional frequency-domain potential flow theory.The results of the hydrodynamic analysis were highly consistent with the test findings,verifying the accuracy of the multifloating hydrodynamic coupling analysis,and key hydrodynamic parameters were solved for different water depths and the coupling effect.According to the obtained results,the hydrodynamic influence was the largest in shallow waters when the coupling effect was considered.Furthermore,the coupled motion equation combined with viscous damping,fender system,and mooring system was established,and the hydrodynamics,floating body motion,and dynamic response of the fender system were analyzed.Motion analysis revealed good agreement among the surge,sway,and yaw motions of the two floating bodies.However,when the wave period reached 10 s,the motion of the two floating bodies showed severe shock,and a relative motion was also observed.Therefore,excessive constraints should be added between the two floating bodies during construction to ensure construction safety.The numerical analysis and model test results of the semisubmersible platform and HYSY 229 barge at a water depth of 42 m and sea conditions of 0°,45°,and 90° were in good agreement,and the error was less than 5%.The maximum movement of the HYSY 229 barge reached 2.61 m in the sway direction,whereas that of the semisubmersible platform was 2.11 m.During construction,excessive constraints should be added between the two floating bodies to limit their relative movement and ensure construction safety.展开更多
Automotive lightweight and safety performance come into play as key technologies to promote competiveness, and average applied amount of automotive plastics has become a significant sign for automotive industrial deve...Automotive lightweight and safety performance come into play as key technologies to promote competiveness, and average applied amount of automotive plastics has become a significant sign for automotive industrial development level of a country.Various performances of a vehicle with plastic automotive fenders are analyzed in the paper.The research is emphasized on sinking-resistance and pedestrian protection performance of the plastic fenders by studying plastics characteristics and simulation analysis.It offers references for engineering design in which both automotive lightweight and safety performance are achieved and well balanced.展开更多
Steel fenders are increasingly used for ship-impact resistance structures in the design of navigable bridges. As an important approach to investigating this anti-impact structure effectiveness to reduce influences of ...Steel fenders are increasingly used for ship-impact resistance structures in the design of navigable bridges. As an important approach to investigating this anti-impact structure effectiveness to reduce influences of vessel impact, simulation analyses are still not perfect yet. So this paper is intended to discuss several issues related to ship collision simulations, including steel constitutive relationship, connections between steel box and pile cap, contacts definition and friction consideration, and the determination of impact waterlines and angles. Consequently based on two examples of ship-steel fender-bridge structure systems, some conclusions about effectiveness and design of fenders to reduce ship impact are drawn.展开更多
Eric Johnson不仅是位出众的吉他手,他还是一名很有品位的艺术鉴赏家,从他指间滑出的音符充满了甜蜜的爱意与美丽的畅想!
提起Eric Johnson,我想大家再熟悉不过了,他毕生都在追求完美的吉他旋律与和声,他那带有魔法般的手指落... Eric Johnson不仅是位出众的吉他手,他还是一名很有品位的艺术鉴赏家,从他指间滑出的音符充满了甜蜜的爱意与美丽的畅想!
提起Eric Johnson,我想大家再熟悉不过了,他毕生都在追求完美的吉他旋律与和声,他那带有魔法般的手指落在他的吉他上简直就像行云流水一样,一切那么的自然、和谐.如此这般的吉他大师怎能缺少一把适合自己的"御用吉他"?……展开更多
In the designing of the flexible fender pile, M-method is usually adopted. But M-method is usable only in the case that the value of the force (moment M and shear force Q) exerted on the pile above the soil is known. ...In the designing of the flexible fender pile, M-method is usually adopted. But M-method is usable only in the case that the value of the force (moment M and shear force Q) exerted on the pile above the soil is known. In practical cases, only the percussive energy of the ship can be found, while the exact value of the percussive force cannot be computed directly. In this paper, a method is introduced which can be used to calculate the inner force of flexible fender piles by a computer in these cases. First, according to the known docking dynamic energy of a ship, the absorbed energy can be found from the deformation of the pile and the rubber fender respectively, at the same time the value of the force acting on the fender piles and the reaction of fenders can be calculated. Then the inner force and displacement of the fender piles can also be calculated further by M-method. The whole computing process is realized by a computer program and the results obtained are reasonable. In this paper, the computation, the iteration method and the computer program are all expounded in detail. This method can be applied to the design of fender piles and type selection of rubber fenders in practical projects.展开更多
基金the National Natural Science Foundation of China(No.U20A20328).
文摘In this paper,the multi-body coupled dynamic characteristics of a semisubmersible platform and an HYSY 229 barge were investigated.First,coupled hydrodynamic analysis of the HYSY 229 barge and the semisubmersible platform was performed.Relevant hydrodynamic parameters were obtained using the retardation function method of three-dimensional frequency-domain potential flow theory.The results of the hydrodynamic analysis were highly consistent with the test findings,verifying the accuracy of the multifloating hydrodynamic coupling analysis,and key hydrodynamic parameters were solved for different water depths and the coupling effect.According to the obtained results,the hydrodynamic influence was the largest in shallow waters when the coupling effect was considered.Furthermore,the coupled motion equation combined with viscous damping,fender system,and mooring system was established,and the hydrodynamics,floating body motion,and dynamic response of the fender system were analyzed.Motion analysis revealed good agreement among the surge,sway,and yaw motions of the two floating bodies.However,when the wave period reached 10 s,the motion of the two floating bodies showed severe shock,and a relative motion was also observed.Therefore,excessive constraints should be added between the two floating bodies during construction to ensure construction safety.The numerical analysis and model test results of the semisubmersible platform and HYSY 229 barge at a water depth of 42 m and sea conditions of 0°,45°,and 90° were in good agreement,and the error was less than 5%.The maximum movement of the HYSY 229 barge reached 2.61 m in the sway direction,whereas that of the semisubmersible platform was 2.11 m.During construction,excessive constraints should be added between the two floating bodies to limit their relative movement and ensure construction safety.
基金Supporting Program of the"Twelfth Five-year Plan"for Sci & Tech Research of China(No. 2011BAG03B02No.2011BAG03B06)
文摘Automotive lightweight and safety performance come into play as key technologies to promote competiveness, and average applied amount of automotive plastics has become a significant sign for automotive industrial development level of a country.Various performances of a vehicle with plastic automotive fenders are analyzed in the paper.The research is emphasized on sinking-resistance and pedestrian protection performance of the plastic fenders by studying plastics characteristics and simulation analysis.It offers references for engineering design in which both automotive lightweight and safety performance are achieved and well balanced.
文摘Steel fenders are increasingly used for ship-impact resistance structures in the design of navigable bridges. As an important approach to investigating this anti-impact structure effectiveness to reduce influences of vessel impact, simulation analyses are still not perfect yet. So this paper is intended to discuss several issues related to ship collision simulations, including steel constitutive relationship, connections between steel box and pile cap, contacts definition and friction consideration, and the determination of impact waterlines and angles. Consequently based on two examples of ship-steel fender-bridge structure systems, some conclusions about effectiveness and design of fenders to reduce ship impact are drawn.
文摘 Eric Johnson不仅是位出众的吉他手,他还是一名很有品位的艺术鉴赏家,从他指间滑出的音符充满了甜蜜的爱意与美丽的畅想!
提起Eric Johnson,我想大家再熟悉不过了,他毕生都在追求完美的吉他旋律与和声,他那带有魔法般的手指落在他的吉他上简直就像行云流水一样,一切那么的自然、和谐.如此这般的吉他大师怎能缺少一把适合自己的"御用吉他"?……
文摘In the designing of the flexible fender pile, M-method is usually adopted. But M-method is usable only in the case that the value of the force (moment M and shear force Q) exerted on the pile above the soil is known. In practical cases, only the percussive energy of the ship can be found, while the exact value of the percussive force cannot be computed directly. In this paper, a method is introduced which can be used to calculate the inner force of flexible fender piles by a computer in these cases. First, according to the known docking dynamic energy of a ship, the absorbed energy can be found from the deformation of the pile and the rubber fender respectively, at the same time the value of the force acting on the fender piles and the reaction of fenders can be calculated. Then the inner force and displacement of the fender piles can also be calculated further by M-method. The whole computing process is realized by a computer program and the results obtained are reasonable. In this paper, the computation, the iteration method and the computer program are all expounded in detail. This method can be applied to the design of fender piles and type selection of rubber fenders in practical projects.
