| Aviation products will inevitably encounter various enviro nmental tests during transportation and use.Among them,the damage caused by vibration is the most extensive and the results are even worse.With the development of environmental vibration test techno logy and the increasing requirements of products in actual use,the assessment of products after prod uction has become particularly important.Vibration test fixture is used as a transition piece for fixing the test p iece and transmitting vibration.Its structural design,production and installation level are directly related to whether the test piece is under the specified test conditions,and it also plays an impo rtant role in the reliability of the results.It is difficult to design the vibration fixture based on experience to reach the vibration environment specified in the product specification.This article focuses on how to reasona bly determine the structure size value of an airborne actuator vibration fixture du ring the design process,and the following research is carried out:(1)The design standards o f fixtures and the the structure and selection of several typical general-purpose vibration fixtures are explored;for the boundary conditions and test requirements of a certain type of linear actuator,the modeling and construction of fixtures under two different structural forms are completed under the guidance of influencing factors in the design process.The simulation analysis shows that the first-order natura l frequency value of the cas ting type fixture is higher than that of the screw connection type,and the error of the root mean square value of t he response point is smaller than that of the screw connection type.(2)By comparing the simulation results,the overall casting structure was selected,and the vib ration test of the actuating mechanism w as completed.Taking the Y-axis test data as an example to analyze,the maximum errors of the fr ont function test,endurance test and post function test were 0.40%,0.24% and 0.76%,the amplification effect of the vibration magnitude is within ±2σ,the fix ture meets the requirements of use,and it also verifies that the simulation result is feasible as a performance evaluation standard.(3)An optimization scheme with quality a nd natural frequency as the objective was proposed.The multi-objective genetic algorithm was introduced under the co-simulation of Creo and ANSYS Workbench to complete the optimization process.The results showed that the optimized fixture model still met the fixture design specification standards,and the quality was reduced by 17.59%.At the same time,the first-order natural f requency value has increased by 30.13%.(4)Combining the relationship between the four design parameters selected in the optimization process and the output target,the parametric design method of the vibration fixture of the linear actuator is determined.A finite element simulation was carried out for a vibration fixture with poor transfer performance.The results are no differen t from the actual measurement.The fixtur e improvement is completed based on the parametric design method.The simulation results show that the i mproved fixture first-order natural frequency value is compared with The original fixture has increased by 114.92 Hz,and the mass has been reduced by 7.739 kg.Although the response spectrum at point A of the improved fixture in the Y direction still has an amplification of the excitation spectrum,the peak value is significantly smaller than that of the original fixture,and the response acceleration ro ot mean square is also Compared with the previous decrease of 0.34%,it shows that the improved fixture can have more excellent performance during the test.Through the design of the vibration fixture of a certain t ype of linear actuator and the optimization of key parameters,the parameter design method of the vibration fixture of the actuator is obtained,which can provide a reference for the design of the vibration fixture of similar structures. |
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