Research For Energy Flow Path In Sheet Structure

The vibration problem of the thin plate is one of the significant problems in the vibration field.The structural intensity method has been developed rapidly in recent years.It is a method to study the vibration mechanism by investigating the energy distribution in an elastic structure.In the previous research,the structural intensity method is mainly used to study the vibration energy distribution when the thin plate is static and there are a few related studies on the moving thin plate.When the thin plate occurs the nonlinear dynamic behavior,such as the doubling periodic motion,quasi-periodic motion,chaos et al,the vibration energy distribution in the thin plate has not been reported.In this thesis,the vibration of the elastic cantilever thin plate is analyzed,and the structural intensity technology combined with the energy visualization method is used to study the evolution process of the vibration energy distribution when the impact occurs.The mainly works include:(1)Mathematical modeling of cantilever thin plate was carried out by using finite element theory considering the external force and impact.and numerical simulation of the model was carried out and the penalty function is employed to deal with the impact problem;(2)Based on the structural intensity formula,the value and direction of the vibration energy of every element in the thin plate can be obtained,and using the streamline diagram,the distribution of vibration energy can be displayed visually;(3)The distribution of vibration energy is exhibited of the impacted cantilever plate,suffering the impulsive force and the harmonic force respectively.Especially,the nonlinear dynamic behaviors such as 1-period motion,multiple-period motion,quasi-periodic motion and chaos are observed in the impacted cantilever plate,suffering the harmonic force,and at that time the distribution diagrams of vibration energy are obtained.The conclusions obtained have certain theoretical significant and application value for studying of the vibration char.