Dynamic Analysis Of Composite Rotational Shell Moving Axially In High Speed

The structure of rotational shell is simple,aerodynamic shape is better,and strength is high.Specially,the shell made of composite materials are widely used in missile structure for its designing of strength and less heavy.The velocity,aerodynamic load,thermal load and other factors affect the vibration characteristics of missile body structure during the flight,which will lead to the instability and damage of missile body structure.Therefore,the research on the moving composite rotating shell has theoretical significance and engineering application value.The axially moving composite rotating shell is established as a mechanical model,and the effects of various parameters on it are studied.The research contents are as follows:(1)Based on the classical thin shell theory and composite laminate theory,the constraint spring is introduced to simulate the boundary conditions,and the expressions of strain energy,kinetic energy and boundary spring potential energy are given.Jacobian polynomials and Fourier series are used as the displacement functions of the shell along the generatrix direction and the circumferential direction respectively.The Rayleigh Ritz method is used to establish the dynamic governing equations of the rotating shell.The natural frequency and mode shape of the rotational shell with different size parameters,boundary conditions and layering angles are numerically calculated,and compared with the literature and finite element simulation results.(2)Based on Hamiltonian principle,the dynamic equations of axially moving composite spherical and cylindrical shells are established.The Galerkin method is used to discretize the dynamic equations.The effect of rigid body motion on the vibration stability of elastic body is studied based on the state space method.The effects of motion speed,shell size and boundary conditions on the stability of high-speed moving composite rotating shells are analyzed.(3)The connecting spring is introduced to simulate the displacement and force continuity conditions at the joint of spherical shell and cylindrical shell.Considering aerodynamic force and axial thrust,the potential energy,aerodynamic force and virtual work of axial thrust are calculated respectively.Based on Hamiltonian principle,the dynamic equation of composite hemispherical shell-cylindrical composite shell is established.The equations are discretized by Galerkin method,and the effects of velocity,dimension parameters,axial thrust and ply angle on the dynamic characteristics of high-speed composite shells are analyzed.(4)Considering the temperature load,the dynamic equation of composite shell is established.The influence of temperature on the natural vibration characteristics of the moving composite shell is studied;the influence of temperature on the dynamic characteristics of the composite shell under different speeds is studied;the influence of temperature on the vibration characteristics of the composite shell under different angle-ply is studied.