Thermal Flexible Coupling Dynamic Analysis Of Flexible Beam Plate System Based On The Absolute Nodal Coordinate Formulation

With the development of space science and technology,multibody systems are gradually developing towards large size,flexibility,lightweight and topology complexity.The linear elastic theory and the first approximation model based on the small deformation model can not reach the accuracy requirements.Therefor,the Absolute Nodal Coordinate Formulation(ANCF)is gradually used to model the multibody systems with the large deformation and overall motion.However,with the increasing scale of flexible multibody systems,both dynamic analysis and kinematic optimization require time-consuming and complex numerical calculations.When directly analyzing the dynamic characteristics of such systems,the calculation cost is quite expensive and the calculation efficiency is low.Therefore,it is necessary to reduced the order of the flexible multibody systems to improve the efficiency of numerical simulation.With the influence of various nonlinear conditions such as geometric nonlinearity,material nonlinearity,multi physical field coupling and other factors,the dynamic equations modeled based on ANCF,generally have the characteristics of nonlinearity.The traditional methods such as Component Mode Synthesis can not be directly applied to reduce those highly nonlinear dynamic equations.In addition,the traditional ANCF three-dimensional beam element is mostly used to model the beam with rectangular cross section,while in aerospace engineering the beam element with circular or ring cross section are widely used in spacecraft structures such as the deployable solar array,satellite antenna ribs,etc.This paper focuses on the beam and plate multibody system described based on ANCF,and researches are carries out as follow:A full parameter three-dimensional ANCF beam element with circular cross-section of multi-layer materials is propoded.Based on the three-dimensional beam element with rectangular section,the unified expression of circle and ring section integrals is given by changing the expression of section integrals.Different elastic force models can be used for different layers.The wire with rubber are used as an example.The internal metal material is described by an isotropic elastic force model,and the external rubber which is incompressible materials is described by Mooney-Rivlin model.The feasibility of the element is verified by static and dynamic numerical examples.In order to solve the problem of computational efficiency of nonlinear dynamic equations of flexible multibody systems,a model order reduction method for flexible multibody systems with large rotation and deformation coupling is proposed.The nonlinear dynamic motion process is divided into multiple linearized regions.In each linearized region,the Taylor expansion is used to expand the dynamic equation,and the the higher-order terms are ignored.The Jacobian matrix of the elastic force is treated as a constant matrix in each linearized region.Then,the free-interface component mode synthesis method is used to reduce the order of the linearized dynamic equation.The degree of freedom of the system is greatly reduced.The generalized-α Solver is used to solve the reduced dynamic equation,and the overall solution flow is given.Without losing accuracy,it can effectively improve the calculation efficiency of flexible multibody system with large rotation and deformation.A model order reduction method of the multi flexible body system based on coupling of the temperature field and displacement field described by ANCF is proposed.The displacement field and temperature field are described by a unified ANCF shape function.At the same time,the dynamic equation and heat transfer equation are linearized by Taylor expansion.Then,the Jacobian matrix of elastic force and the Jacobian matrix of thermal stress are taken as generalized stiffness matrices,which are regarded as constants within the linearization region.The free-interface component mode synthesis method is used to reduce the order of the linearized dynamic equation and heat transfer equation.The degree of freedom of the reduced dynamic equation and heat transfer equation is much less than the full degree of freedom system equation,which can effectively improve the calculation efficiency of the thermal flexible coupling system.Modeling and thermal dynamic coupling analysis of the beam plate system such as solar panel support and large aperture parabolic antenna are carried out.The circular beam element and the thin plate element of ANCF thermal coupling are used to discretize the deployable solar array and the large parabolic antenna.The coupling of temperature field and displacement field is considered.With high accuracy,the dynamic equation and heat transfer equation are solved efficiently by using the reduced order method.Considering the influence of one side solar heat flux,the deployment of solar panel support will be slightly affected.Under the influence of boundary conditions such as solar heat flux,self shielding and radiation heat emission,the parabolic antenna array will have uneven temperature rise,which will affect the electrical performance of the antenna.