Light Weight Optimization Design for a Connection Frame Considering Thermal-Structural Coupling Deformation

Abstract

Connection frame, as a key module in macro-micro motion platform, is employed to realize a high acceleration, high speed and ultra-precision positioning motion. In the paper, six working conditions of connection frame are obtained by analyzing its driving processes. The maximum deformation in the different working conditions is calculated by the mechanical analysis which affects ultra-precision positioning. Moreover, the maximum deformation of thermal-structural coupling analysis increases the influence on the positioning. Under the same situation, the change trends of deformation and stress distribution of connection mechanism can be obtained by changing the surface loads. The maximum deformation and stress increase with the loads. However, for ever-increasing market demand, it is not adequate to only consider high acceleration under accuracy requirement. The higher acceleration is needed by light weight of connection frame. Therefore, an optimization model is built and studied, which takes the weight of connection frame as objective and takes the thermal deformation as constraint. Connection frame structure model can be calculated in ANSYS and the optimal solution can be obtained by genetic algorithm (GA) in MATLAB. With MATLAB and ANSYS optimization, the rate of convergence has been improved by 3%. Design variables for optimal solution are obtained. The weight and the maximum thermal-structural coupling displacement have been improved by 24.3% and 27.3% respectively. The first six order vibration modes of connection frame are obtained by the finite element method. And the simulation data can be verified by experiment. At last, an optimization connection frame structure considering thermal-structure coupling deformation is obtained.