Parameter Optimization Design Of Compliant Mechanisms With Brackets

With the development of the industry, noise pollution has now become a serious environmental problem. The design and optimization of compliant mechanisms become the focus of current research because of its good damping characteristics. In the present study, the effect of compliant mechanisms parameters on the natural frequency was investigated, then the structure parameters were optimized. The specific research contents are as follows:Firstly, a compliant mechanism with brackets was designed, then modal analysis and harmonic response analysis of the mechanism were conducted with ANSYS, thus the relationship between the natural frequency and vibration characteristics with damping case or not was studied. Afterwards, the effect of parameters variations on the natural frequency was investigated by changing the position parameters and geometric parameters. Find the structure parameters of a greater influence on the natural frequency, then conduct a comprehensive experiment on these parameters and use ANSYS to obtain the natural frequency. Fit the data through the method of radial basis function (RBF), and construct the model of the agent. Thus, the RBF agent model was validated through precision analysis. At last, one parameter of the RBF model was fixed to study the effect of the other two parameters on the natural frequencies.Secondly, in order to obtain better sound absorption characteristics in a certain frequency for the mechanism, the standard particle swarm optimization algorithm (PSO) to optimize the multiple parameters based on the agent model was utilized. At First, the agent model was optimized for the minimum natural frequency:The parameter values with the minimum natural frequency for the mechanism were calculated through MATLAB. Then the natural frequency of the mechanism with the obtained parameter values was analyzed with ANSYS. The changes of natural frequency before and after optimization was observed. The result shows that the natural frequency decrease more than 20% relative to the initial frequency. Then the model was optimized for the given natural frequency:The particle swarm optimization algorithm was used to find out the corresponding parameter values of the mechanism with the given natural frequency. Based on the parameter values obtained, a natural frequency analysis was conducted with ANSYS. Compared the frequency of obtained and the frequency calculated in ANSYS which shows that its error is less than 5%. Thus, we get the appropriate parameters for the mechanism of which the natural frequency is close to the given natural frequency.Finally, the particle swarm optimization algorithm was utilized to optimize the 2-dimension position of the bracket in a square compliant mechanism. Firstly, the cubic method in MATLAB was used to describe the relationship between the natural frequency and the bracket location. Then the agent model was optimized to calculate multiple bracket positions with the minimum natural frequency. According to the results of optimization, the natural frequency analysis was conducted with ANSYS. The calculated natural frequency agrees well with the given frequency, with the error less than 5%. Thus, the particle swarm optimization algorithm is valid for the double parameters optimization for the given natural frequency.