A numerical model was developed by using the dual boundary element method to investigate the dynamic behavior of a moored floating structure with a pair of vertical and flexible skirts attached at its bottom in the li...A numerical model was developed by using the dual boundary element method to investigate the dynamic behavior of a moored floating structure with a pair of vertical and flexible skirts attached at its bottom in the linear wave field. Theoretical conception is based on potential theory with linear external forces. The motions of the structure were assumed to be small and linear. The flexible skirts mounted beneath the structure were assumed uniform flexural rigidity and the thickness of the skirts was negligible. Comparison between the present model and Gesraha＇s solution was made to verify the results for a moored floating structure with or without rigid skirts. The influence of the skirt rigidity on the moored floating structure, moored lines and waves is investigated in this study. The results show that, the natural frequencies of structure＇s oscillation, moored force, wave reflection and transmission tend to the region of short-period waves when the flexible rigidity gradually decreases. Positive correlation exists between the aft mooring force and the pitch motion of the floating structure.展开更多
Based on the theory of nonlocal elasticity,a nonlocal shell model accounting for the small scale effect is developed for the bending characteristics of CNTs subjected to the concentrated load.With this nonlocal shell ...Based on the theory of nonlocal elasticity,a nonlocal shell model accounting for the small scale effect is developed for the bending characteristics of CNTs subjected to the concentrated load.With this nonlocal shell model,explicit expressions are derived for the bending solutions.To extract the proper values of nonlocal scale parameter,we have made molecular dynamics(MD) simulations for various radii and lengths of armchair and zigzag CNTs,the results of which are matched with those of nonlocal continuum model.It is found that the present nonlocal elastic shell model with its appropriate values of nonlocal scale parameter has the capability to predict the bending behavior of CNTs,which is comparable with the results of MD simulations.Moreover,exact closed form solutions for the nonlocal scale parameter for zigzag and armchair CNTs are obtained.The results show that nonlocal scale parameter is independent of the length of CNTs,and dependent on the radius of CNTs.展开更多
文摘A numerical model was developed by using the dual boundary element method to investigate the dynamic behavior of a moored floating structure with a pair of vertical and flexible skirts attached at its bottom in the linear wave field. Theoretical conception is based on potential theory with linear external forces. The motions of the structure were assumed to be small and linear. The flexible skirts mounted beneath the structure were assumed uniform flexural rigidity and the thickness of the skirts was negligible. Comparison between the present model and Gesraha＇s solution was made to verify the results for a moored floating structure with or without rigid skirts. The influence of the skirt rigidity on the moored floating structure, moored lines and waves is investigated in this study. The results show that, the natural frequencies of structure＇s oscillation, moored force, wave reflection and transmission tend to the region of short-period waves when the flexible rigidity gradually decreases. Positive correlation exists between the aft mooring force and the pitch motion of the floating structure.
基金supported by the National Natural Science Foundation of China (Grant No. 11132002)Guangdong Province (Grant No.10151064101000062)the Ph.D. Programs Foundation of Ministry of Education of China (Grant No. 20110172110031)
文摘Based on the theory of nonlocal elasticity,a nonlocal shell model accounting for the small scale effect is developed for the bending characteristics of CNTs subjected to the concentrated load.With this nonlocal shell model,explicit expressions are derived for the bending solutions.To extract the proper values of nonlocal scale parameter,we have made molecular dynamics(MD) simulations for various radii and lengths of armchair and zigzag CNTs,the results of which are matched with those of nonlocal continuum model.It is found that the present nonlocal elastic shell model with its appropriate values of nonlocal scale parameter has the capability to predict the bending behavior of CNTs,which is comparable with the results of MD simulations.Moreover,exact closed form solutions for the nonlocal scale parameter for zigzag and armchair CNTs are obtained.The results show that nonlocal scale parameter is independent of the length of CNTs,and dependent on the radius of CNTs.
