Research On Configuration Method For Parallel Compliant Mechanism Via Mixed Constraints

With the rapid development of science and technology,compliant mechanisms have potential applications in the fields of micro-electromechanical systems, robot,aeronautics and astronautics. At present, with the complicated work environment and the high work requirement, the single physical field is only considered, and the optimum of single performance index is pursued. It is difficult to achieve the design requirement of mechanisms. Therefore, the effective design method is needed to solve the above problem. parallel compliant mechanisms comprehensively consider geometric constraint, physical constraint and performance constraint. The synthesis method of mixed constraints is proposed. The thesis is researched from the following aspects.Based on the method of freedom and constraint topology of parallel compliant mechanisms, freedom space, constraint space and sub-constraint space are constructed. The stiffness matrix of compliant element of parallel compliant mechanisms is derived, and the total stiffness matrix of parallel compliant mechanisms is obtained.Force isotropy degree, torque isotropy degree, force sensitivity and torque sensitivity of parallel compliant mechanisms are researched. Compliant mechanisms are influenced by the temperature field, and mechanisms produce thermal deformation. Therefore, the heat balance equation of parallel compliant mechanisms is established. The thermal load of force equivalent nodal and torque equivalent nodal are solved. With the thermal load of equivalent nodal as constraint condition, and sensitivity degree or isotropy degree as objective function. The optimization model of cylindrical compliant element, square compliant element and blade compliant element are established. The design software of parallel compliant mechanisms with multiple degrees of freedom and visualization is developed by the optimization model.The software is applied. With force sensitivity and torque sensitivity as the objective function, the parameters of parallel compliant mechanism are carried out multi-objective optimization. the optimized parameter is applied. parallel compliant mechanism is carried out the finite element simulation. Three orders natural frequencies and main vibration mode are obtained. parallel compliant mechanism with three degrees of freedom is developed. parallel compliant mechanism is researched with the static experiment. The linearity of output displacement is obtained. The linear characteristic is better. Parallel compliant mechanism is carried out modal experiment analysis using hammering method. The amplitude frequency and phase frequency characteristic along the X axis, Y axis and Z axis are obtained.