In this paper, the large deflection theory is adopted to analyse the geometrical nonlinear stability of a sandwich shallow cylindrical panel with orthoiropic surfaces. The critical point is determined and the postbitc...In this paper, the large deflection theory is adopted to analyse the geometrical nonlinear stability of a sandwich shallow cylindrical panel with orthoiropic surfaces. The critical point is determined and the postbitckling behaviour of the panel is studied.展开更多
Based on the hydrodynamic stability theory of distorted laminar flow and the kind of distortion profiles on the mean velocity in parallel shear flow given in paper [1], this paper investigates the nonlinear stability ...Based on the hydrodynamic stability theory of distorted laminar flow and the kind of distortion profiles on the mean velocity in parallel shear flow given in paper [1], this paper investigates the nonlinear stability behaviour of parallel shear flow, carries on stability calculation taking account of the perturbations of background turbulence noise under certain assumption, and obtains some results in accordance qualitatively with those of experiment for plane Poiseuille flow and pipe Poiseuille flow.展开更多
In this paper, a set of variational formulas of solving nonlinear instability critical loads are established from the viewpoint of variational principle. The paper shows that it is very convenient to solve nonlinear i...In this paper, a set of variational formulas of solving nonlinear instability critical loads are established from the viewpoint of variational principle. The paper shows that it is very convenient to solve nonlinear instability critical load by using the variational formulas suggested in this paper.展开更多
The nonlinear finite element method is used to analyze the geometrical nonlinear stability of cable truss domes with different cable distributions. The results indicate that the critical load increases evidently when...The nonlinear finite element method is used to analyze the geometrical nonlinear stability of cable truss domes with different cable distributions. The results indicate that the critical load increases evidently when cables, especially diagonal cables, are distributed in the structure. The critical loads of the structure at different rise span ratios are also discussed in this paper. It was shown that the effect of the tensional cable is more evident at small rise span ratio. The buckling of the structure is characterized by a global collapse at small rise span ratio; that the torsional buckling of the radial truss occurs at big rise span ratio; and that at proper rise span ratio, the global collapse and the lateral buckling of the truss occur nearly simultaneously.展开更多
The study of pedestrian evacuation in channels with different structures is important among optimizing through efficiency,avoiding accidents and designing passageway.It is of significant reference to set up a specific...The study of pedestrian evacuation in channels with different structures is important among optimizing through efficiency,avoiding accidents and designing passageway.It is of significant reference to set up a specific model on account of the real traffic system and design an appropriate controller to apply on it.This paper establishes a macroscopic model for T-shaped channel with a number of controlled entrances basing on the law of mass conservation.Then,with the method of cascade,a kind of sliding mode controller is designed to achieve the control target of avoiding the blocking and maximizing the pedestrian flow of the whole model,the stability of the system is proved by the Lyapunov stability theory,and the boundary layer method is applied to restrain the chattering of the controller.Finally,simulation results show the efficiency of the sliding mode controller and the improvement brought by the boundary layer method.展开更多
文摘In this paper, the large deflection theory is adopted to analyse the geometrical nonlinear stability of a sandwich shallow cylindrical panel with orthoiropic surfaces. The critical point is determined and the postbitckling behaviour of the panel is studied.
文摘Based on the hydrodynamic stability theory of distorted laminar flow and the kind of distortion profiles on the mean velocity in parallel shear flow given in paper [1], this paper investigates the nonlinear stability behaviour of parallel shear flow, carries on stability calculation taking account of the perturbations of background turbulence noise under certain assumption, and obtains some results in accordance qualitatively with those of experiment for plane Poiseuille flow and pipe Poiseuille flow.
文摘In this paper, a set of variational formulas of solving nonlinear instability critical loads are established from the viewpoint of variational principle. The paper shows that it is very convenient to solve nonlinear instability critical load by using the variational formulas suggested in this paper.
文摘The nonlinear finite element method is used to analyze the geometrical nonlinear stability of cable truss domes with different cable distributions. The results indicate that the critical load increases evidently when cables, especially diagonal cables, are distributed in the structure. The critical loads of the structure at different rise span ratios are also discussed in this paper. It was shown that the effect of the tensional cable is more evident at small rise span ratio. The buckling of the structure is characterized by a global collapse at small rise span ratio; that the torsional buckling of the radial truss occurs at big rise span ratio; and that at proper rise span ratio, the global collapse and the lateral buckling of the truss occur nearly simultaneously.
基金the National Natural Science Founda-tion of China(No.61374133)the Natural Science Foun-dation of Jiangsu Province(No.BK20191286)the Fundamental Research Funds for the Central Universi-ties(No.30920021139)。
文摘The study of pedestrian evacuation in channels with different structures is important among optimizing through efficiency,avoiding accidents and designing passageway.It is of significant reference to set up a specific model on account of the real traffic system and design an appropriate controller to apply on it.This paper establishes a macroscopic model for T-shaped channel with a number of controlled entrances basing on the law of mass conservation.Then,with the method of cascade,a kind of sliding mode controller is designed to achieve the control target of avoiding the blocking and maximizing the pedestrian flow of the whole model,the stability of the system is proved by the Lyapunov stability theory,and the boundary layer method is applied to restrain the chattering of the controller.Finally,simulation results show the efficiency of the sliding mode controller and the improvement brought by the boundary layer method.
