A novel symplectic superposition method has been proposed and developed for plate and shell problems in recent years.The method has yielded many new analytic solutions due to its rigorousness.In this study,the first e...A novel symplectic superposition method has been proposed and developed for plate and shell problems in recent years.The method has yielded many new analytic solutions due to its rigorousness.In this study,the first endeavor is made to further developed the symplectic superposition method for the free vibration of rectangular thin plates with mixed boundary constraints on an edge.The Hamiltonian system-based governing equation is first introduced such that the mathematical techniques in the symplectic space are applied.The solution procedure incorporates separation of variables,symplectic eigen solution and superposition.The analytic solution of an original problem is finally obtained by a set of equations via the equivalence to the superposition of some elaborated subproblems.The natural frequency and mode shape results for representative plates with both clamped and simply supported boundary constraints imposed on the same edge are reported for benchmark use.The present method can be extended to more challenging problems that cannot be solved by conventional analytic methods.展开更多
This paper is devoted to the problem of partial asymptotic null-controllability of control sys-tems governed by ordinary differential equations,subjected to possibly mixed state-input con-straints.Using Lyapunov funct...This paper is devoted to the problem of partial asymptotic null-controllability of control sys-tems governed by ordinary differential equations,subjected to possibly mixed state-input con-straints.Using Lyapunov functions within the framework of viability theory,feedback controls are designed in such a way a part of system’s state can be driven to the origin asymptotically,taking into account the mixed constraints.By using Michael selection theorem,the existence of such controls is proved,in the case of convex constraints,and their expressions are given as continu-ous selections of an appropriate constructed multifunction.Finally,two examples are processed numerically in order to illustrate the theoretical results.展开更多
基金the support from the National Natural Science Foundation of China(Grants 12022209,11972103,and 11825202)the Liaoning Revitalization Talents Program of China(Grant XLYC1807126)the Fundamental Research Funds for the Central Universities(Grant DUT21LAB124).
文摘A novel symplectic superposition method has been proposed and developed for plate and shell problems in recent years.The method has yielded many new analytic solutions due to its rigorousness.In this study,the first endeavor is made to further developed the symplectic superposition method for the free vibration of rectangular thin plates with mixed boundary constraints on an edge.The Hamiltonian system-based governing equation is first introduced such that the mathematical techniques in the symplectic space are applied.The solution procedure incorporates separation of variables,symplectic eigen solution and superposition.The analytic solution of an original problem is finally obtained by a set of equations via the equivalence to the superposition of some elaborated subproblems.The natural frequency and mode shape results for representative plates with both clamped and simply supported boundary constraints imposed on the same edge are reported for benchmark use.The present method can be extended to more challenging problems that cannot be solved by conventional analytic methods.
文摘This paper is devoted to the problem of partial asymptotic null-controllability of control sys-tems governed by ordinary differential equations,subjected to possibly mixed state-input con-straints.Using Lyapunov functions within the framework of viability theory,feedback controls are designed in such a way a part of system’s state can be driven to the origin asymptotically,taking into account the mixed constraints.By using Michael selection theorem,the existence of such controls is proved,in the case of convex constraints,and their expressions are given as continu-ous selections of an appropriate constructed multifunction.Finally,two examples are processed numerically in order to illustrate the theoretical results.
