Free-form Planar Curved Beam Configuration Library Based On Static Performance Indices

The compliant curved beam mechanism relies on its own deformation to transfer motion.which has the advantages of saving mechanism space,achieving integrated processing,avoiding mechanical tear,and high transmission accuracy and has received widespread attention from designers.In the design process of compliant curved beam mechanism,in addition to satisfying the requirement of degree of freedom,the structure should also have excellent static properties.Based on the isogeometric analysis,this paper constructs the configuration library of plane compliant curved beams with static performance indices,which provides designers with plane compliant curved beams to meet the requirements of freedom and performance.It improves the structural performance and optimizes the design process at the early stage of design.Based on the NURBS modeling method,the model with geometric parameterization is established,and the shape function in the finite element analysis method is constructed by NURBS basis function.The general stiffness matrix of the plane compliant curved beam is deduced according to the principle of minimum potential energy.On the basis of linear analysis,the tangent stiffness matrix is obtained considering the non-linear relationship between stress and strain,and than solve the non-linear equation.Combined with examples,the static linear analysis and geometric non-linear analysis of general plane compliant curved beams are carried out by using isogeometric analysis and finite element method.The analysis results of the two methods are compared to verify the feasibility and accuracy of the medium geometric method in this paper.Combined with isogeometric analysis,the mapping relationship between the geometric parameters of curved beams and static performance indices including stiffness ratio,decoupling and accompanying displacement is revealed,so that each kind of curved beam has its desired performance.The configuration library with static and mechanical properties is established,which is classified according to the degree of freedom,and the curved beam element is optimized based on genetic algorithm,and the plane is designed.The software of the compliant curved beam configuration library generation system is developed helping facilitates users to select suitable plane compliant curved beams according to the design requirements of curved beams.In order to verify the accuracy and practicability of the configuration library,a planar compliant curved beam mechanism with negative Poisson's ratio is designed and manufactured by combining the configuration library with the FACT method.The mechanism is analyzed by geometric theory and simulated by finite element method.Compared with the results measured by the experiment,it is found that there is an agreement among the theoretical value,simulated value and the experimental values,which confirms the practicability and reliability of the planet curved beam configuration library proposed in this paper.The static configuration library proposed can be widely used in structural design in various fields,such as compliant micro-displacement platform design,compliant bionic structure design,compliant medical device design and so on.