| The eight-link mechanism is the main drive mechanism commonly used by press machine,and its geometric dimension affects the kinematics and dynamics of the press machine.Press with insufficient exercise can cause problems such as pulling,molding,and wrinkles such as metal sheets during stamping.At the same time,the dynamic performance of press machine can cause low drive efficiency,high failure rate,and decrease in service life.Therefore,it is necessary to optimize its dimensional optimization during the design process of the eight-link mechanism.The traditional design methods to optimize inefficient,optimized,usually optimized on the basis of sacrificing other aspects.This paper studies the geometric dimension optimization of the eight-link mechanism for motion and kinetic performance,based on vector parse mechanism for kinematics and dynamics,using penalties genetic algorithm based on vector resolution method.The geometry of the eight-link mechanism optimizes,and introduces the static dynamic performance of the eight-link mechanism of the press machine,and develops the geometric dimension optimization and simulation system of eight-link mechanism for press machine,realized the high efficiency and high reliability of the press machine.The main research contents include:(1)Propose a construction method of kinematics and dynamics parameterization model of eight-link mechanism for press machine based on vector resolution method.Constructs an eight-link mechanism motion equation based on the eight-link mechanism of the topology characteristics.Based on the kinetic analysis of the eightlink mechanism,proposed the rotational inertia of the eight-link mechanism and the calculation method of the centroid position.According to the above analysis and established equations,designed the eight-link mechanism of the press machine parametrically,and simulated the eight-link mechanism of the press machine.Compared with the results of theoretical calculation and simulation analysis,the correctness of the eight-link mechanism parametric model of the press machine is verified.(2)Propose a multi-objective optimization method for eight-link mechanism of press machine based on penalty function genetic algorithm.The kinematics and dynamics characteristics of the eight-link mechanism of press machine are studied in depth,extract constraints and build target function.Based on non-dominant generation algorithms with elite strategy and combined with penalty function,the geometric size of the eight-link mechanism is optimized,and the optimization experiment of the mechanism was carried out with the improved multi-objective optimization algorithm,and the institution has been optimized.The multi-objective optimization design of the eight-link mechanism of press machine is realized.(3)Propose a method of performance simulation method of eight-link mechanism of press machine based on rigid-flexible coupling.The finite element model of eightlink mechanism of press machine is established by using finite element method.The stress and deformation of the mechanism in the working stage are analyzed,and the stiffness and strength of the mechanism are checked.The six-order solid frequency of eight-link mechanism of press machine is extracted with the modal superposition method,and each step-shaped cloud map is analyzed.Establish method of kinematics and dynamics simulation analysis of eight-link mechanism of press machine for motion and kinetics based on flexible aerodynamic is proposed,and the necessity of rigidly coupled model is demonstrated by comparative experiment.(4)Develop geometric dimension optimization and simulation system for eightlink mechanisms of press machine.A graphical interface with good interaction and convenient use is designed,The geometric dimension optimization,motion performance simulation and pressure machine production line stamping simulation are achieved.The reliability of optimization and simulation system is verified by an example application. |
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