Study On Zero-compensation Load Simulator With Double Springs And Analysis Of The Creeping Mechanism

As an important mechanism of aircraft guidance,the performance of the steering gear directly affects the guidance accuracy of the aircraft.The load simulator of the steering gear mainly provides the loading moment for the steering gear to simulate the moment acting on the wing of the steering gear during the flight.Therefore,the high-precision actuator loading simulator is of great value to accurately test the performance of the actuator and improve the flight guidance accuracy of the aircraft.This project comes from the cooperation project of the Institute of space technology,and develops a servo loading simulator with accurate loading and sensitive response.According to the requirements of design index,this paper proposes a structure of double spring coaxial reverse arrangement.By means of spring pre compression,the nonlinearity of spring reverse loading and the change of stiffness are eliminated,and the zero balance range caused by residual stress,friction,zero hysteresis and other factors is reduced.First of all,according to the requirements of the design index,a variety of load simulator schemes were compared and selected.Two schemes of using the cylindrical helical torsion spring and the plane volute spring as the elastic elements of the load simulator were determined.Through the comparison of single and double spring structure,the structure of double spring coaxial reverse arrangement is determined.At last,two schemes were designed in detail.Secondly,the stress-strain properties of the two springs were calculated accurately.The stress expressions of the torsion spring under the load moment of the cylindrical spiral torsion spring were obtained.Through the solution of stress function,the stress distribution on the section of volute spring and the stress distribution on the helix were obtained.Then calculated the two kinds of spring size parameters.According to the model of spring size parameters,ABAQUS was used to simulate the stress and strain,and the results were compared with the theoretical formula.After that,the creep strain of the two springs was analyzed.Based on the original creep constitutive equation at room temperature,the creep constitutive equation of torsion spring and plane volute could be obtained by macro tensile test and compared with the simulation results of ABAQUS.Then,the stress relaxation characteristics of spring were analyzed,and the stress relaxation constitutive equation of spring was obtained.Finally,in order to verify the correctness of the theoretical formula,this paper designed three experiments: spring performance experiment,spring creep strain experiment and spring stress relaxation experiment.The actual performance of the two springs was obtained through the spring performance experiment and compared with the theoretical calculation results.The advantages of double spring structure and the accuracy of theoretical calculation were verified by the comparison of single and double spring experiments and the fitting results of positive and negative load stiffness curves.The relationship between spring creep angle and time was obtained by spring creep strain experiment,which verifies the theoretical calculation results.Through the spring stress relaxation experiment,the stress relaxation constitutive equation and moment relaxation equation of torsion spring and the moment relaxation equation of plane volute spring were obtained.