Stiffness Optimization And Lightweight Design Of Wind Tunnel Model Supporting Mechanism

In the wind tunnel test,the function of the model support mechanism is to support the aircraft model in the test section and drive it to move.The model supporting mechanism is the core equipment and the key link in wind tunnel test.For the model supporting mechanism,it is necessary to choose a reasonable spatial layout and use reliable and effective modern design method to optimize,this will greatly improve the rationality and advancement of the mechanism,thus improving the overall ability of wind tunnel test.This paper investigates the development and research status of model supporting mechanism at home and abroad.Based on the technical indicators,three different forms of space layout are proposed,and their advantages and disadvantages are compared.According to the actual situation,the “five-degree-of-freedom external + rolling internal” series mechanism scheme is selected.Lastly,the design principle and each sub-mechanism of the mechanism are introduced.The model supporting mechanism is layered in space and has six degrees of freedom,so the mechanism can be divided into six sub-mechanisms.The pitching mechanism is identified as the weakest sub-mechanism of the mechanism through modal analysis,harmonic response analysis and rigidization of each sub-mechanism.After that,Ansys static analysis and ADAMS simulation of the pitching mechanism are done.The results show that the mechanism satisfies the design requirements.Secondary identification of the weak links of the pitching mechanism by the same method shows that the main supporting plate is the weakest link of the pitching mechanism.The stiffness of the main support plate is optimized by sensitivity analysis method,and the harmonic response of the pitching mechanism before and after optimization is analyzed.It is concluded that the maximum resonance point amplitude of the pitching mechanism in the X and Y directions decreases,and the corresponding resonance frequency increases accordingly.The model of main supporting plate is imported into Ansys Workbench.And the topology optimization weight reduction design is carried out by using Topology Optimization module.According to the pseudo-density cloud of the output results,the material in some areas is removed,and the goal of weight reduction has been achieved.Response Surface Optimization module is used to optimize the main supporting plate,the size and relative position of the weight-reducing holes are optimized.Finally,the main supporting plate achieves the weight-reducing effect while maintaining the maximum stiffness.