The elongating of cable-stayed bridge brings a series of aerodynamic problems. First of all,geometric nonlinear effect of extreme long cable is much more significant for cable-stayed bridge spanning over one thousand ...The elongating of cable-stayed bridge brings a series of aerodynamic problems. First of all,geometric nonlinear effect of extreme long cable is much more significant for cable-stayed bridge spanning over one thousand meters. Lateral static wind load will generate additional displacement of long cables,which causes the decrease of supporting rigidity of the whole bridge and the change of dynamic properties. Wind load,being the controlling load in the design of cable-stayed bridge,is a critical problem and needs to be solved. Meanwhile,research on suitable system between pylon and deck indicates fixed-fixed connection system is an effective way for improvement performance of cable-stayed bridges under longitudinal wind load. In order to obtain aerodynamic parameters of cable-stayed bridge spanning over one thousand meters,identification method for flutter derivatives of full bridge aero-elastic model is developed in this paper. Furthermore,vortex induced vibration and Reynolds number effect are detailed discussed.展开更多
For nonlinear coupled system of multilayer dynamics of fluids in porous media, the second order and first order upwind finite difference fractional steps schemes applicable to parallel arithmetic are put forward, trod...For nonlinear coupled system of multilayer dynamics of fluids in porous media, the second order and first order upwind finite difference fractional steps schemes applicable to parallel arithmetic are put forward, trod two-dimensional and three-dimensional schemes are used to form a complete set. Some techniques, such as calculus of variations, multiplicative commutation rule of difference operators, decomposition of high order difference operators and prior estimates, are adopted. Optimal order estimates in L2 norm are derived to determine the error in the second order approximate solution. This method has already been applied to the numerical simulation of migration-accumulation of oil resources.展开更多
文摘The elongating of cable-stayed bridge brings a series of aerodynamic problems. First of all,geometric nonlinear effect of extreme long cable is much more significant for cable-stayed bridge spanning over one thousand meters. Lateral static wind load will generate additional displacement of long cables,which causes the decrease of supporting rigidity of the whole bridge and the change of dynamic properties. Wind load,being the controlling load in the design of cable-stayed bridge,is a critical problem and needs to be solved. Meanwhile,research on suitable system between pylon and deck indicates fixed-fixed connection system is an effective way for improvement performance of cable-stayed bridges under longitudinal wind load. In order to obtain aerodynamic parameters of cable-stayed bridge spanning over one thousand meters,identification method for flutter derivatives of full bridge aero-elastic model is developed in this paper. Furthermore,vortex induced vibration and Reynolds number effect are detailed discussed.
文摘For nonlinear coupled system of multilayer dynamics of fluids in porous media, the second order and first order upwind finite difference fractional steps schemes applicable to parallel arithmetic are put forward, trod two-dimensional and three-dimensional schemes are used to form a complete set. Some techniques, such as calculus of variations, multiplicative commutation rule of difference operators, decomposition of high order difference operators and prior estimates, are adopted. Optimal order estimates in L2 norm are derived to determine the error in the second order approximate solution. This method has already been applied to the numerical simulation of migration-accumulation of oil resources.
