Simulation Study Of Wind Tunnel Test Model Support System Based On Parallelogram Mechanism

With the development of science and technology, in the aerospace field, people found that the flight can be controlled, when the aircraft reaches or exceeds the stall angle of attack, which will greatly improve the combat effectiveness of aircraft flying in the air, it has become a very important technology, the general methods to study are including flight experiment, theoretical analysis method, wind tunnel test and so on. The wind tunnel test is in favor of the world powers because of its low cost, short test cycle and other advantages. And model support technology is the key point of wind tunnel based virtual flight testing, because it can make the test get a more accurate and reliable data and reveal the possible problems, define the measures for improvements, so as to reduce the risk of flight test.A wind tunnel testing bed which is based on the parallelogram mechanism was given in this paper, and the design of the key parts stability analysis, the establishment of virtual prototype model, and movements under different working conditions are discussed in detail in this paper, which would lay the foundation for the establishment of compensation algorithm in control system.Firstly, the thesis introduces the research background and analyze some representative model support systems at home and abroad; secondly, the author writes the object of this paper and analyzes its structure and operating principles. Secondly, in view of the defects in the stiffness, bearing capacity as parallel mechanism, the author can use Ansys Workbench software to get the change rule of the maximum deformation under the condition of external load and different gesture. Then according to the main support part, in the rod’s length, thickness under different circumstances, the author uses Ansys Workbench to analyze the entire system to obtain a higher rigidity, good stability system. Thirdly, the author analyzes the modal of the whole system, obtaining the six natural frequencies and mode shapes, which provides a reference to avoid the resonance frequency. Fourthly, the author establish the virtual prototype model and makes the support system flexible to obtain the rigid flexible hybrid model by Adams software.Taking the example of pitching movement,the author analysis the pure rigid body and rigid flexible hybrid model simulation results.A conclusion is obtained that rigid body will not meet the requirements of precision. Finally, author makes the model supporting system flexible and simulate the movement when it is in the wind tunnel, which can obtain the motion characteristics under different wind speed, different frequencies and different amplitudes by using control variable method.