Model Establishment And Motion Deformation Analysis Of Flexible Plate Based On The Absolute Nodal Coordinate Formulation

With the continuous emergence of new materials and new technologies,rigidflexible coupling systems with large deformation components are increasingly widely used in robotics,aerospace,machinery and other fields.The traditional rigid-flexible coupling dynamics theory based on the small deformation assumption can not completely solve the deformation motion problem of such systems.The absolute nodal coordinate Formulation(ANCF)fundamentally was realized the modeling of multi-dimensional rigid-flexible systems without decoupling.In this thesis,according to the ANCF method,the large deformation and large rotation of three typical flexible plates are simulated and modeled.The NURBS is used to describe the displacement field,and the rational RANCF thin plate element is obtained.The model with initial configuration is described accurately.The dynamic modeling of flexible plate element without initial configuration is carried out,and the large deformation problem of ANCF plate element is analyzed.Firstly,ANCF-P4443,ANCF-P3433 and ANCF-VT3833 plate elements are established.Based on the traditional elastic mechanics theory,the dynamic equation of ANCF plate is obtained for dynamic modeling and simulation of flexible plate.Then,a simulation example of large deformation and large rotation of ANCF flexible plate model without initial configuration is given.The simulation results are compared with the results of finite element commercial software for kinematics and deformation characteristics.The results show that the ANCF plate element has obvious advantages in describing the large deformation and large rotation of the flexible body.The mapping relationship between ANCF thin plate and non-rational B-spline surface and NURBS surface is deduced.In order to avoid the limitations of the power basis function to describe the displacement field,the mapping relationship between the mixed high-order ANCF thin plate model and the rational bicubic B-spline surface and the non-rational bicubic B-spline surface is derived respectively,and the transformation relationship between the two is clarified.The results show that the non-rational bicubic B-spline surface can be mapped to ANCF-P4453 thin plate,and NURBS surface can be mapped to RANCF thin plate.The dynamic modeling and simulation of ANCF thin plate model with initial configuration are carried out.Firstly,the problem that the ANCF thin plate element lacks the gradient vector in the thickness direction is solved by introducing the middle layer normal vector as the gradient in the thickness direction of the thin plate element,and the complete elastic force expression of the ANCF thin plate element with initial configuration is derived.The results show that the simulation results of RANCF thin plate element,ANCF-P4453 element and ANCF-P3433 element are highly consistent when describing the non-initial configuration and non-rational configuration models.The RANCF thin plate element has higher accuracy and convergence when describing the rational configuration.