Motion Simulation And Transfer Function Analysis Of Lever System For Wing Structure Test

The test of wing structure is usually carried out through lever system,and the method to predict levers displacement and establish geometric model under the condition of large deformation of wing structure are studied,which can be used in the design of loading and test equipment installation.Firstly,the force balance relations and the nonlinear equation satisfying the geometric parameters of a single lever were established by force analysis.Then the equilibrium equations of the whole lever group were obtained according to the connection relation of each lever.After changing the location of the loading point of the wing structure and the position of the actuator suspension point step by step,the spatial positions of the two ends of each lever in the lever system under large deformation of the wing structure and dynamic loading condition were calculated based on the numerical algorithm.Based on this method,the initial position of radial lever system was determined.Using the secondary-development-function of CATIA,the parameterized modeling software was developed and improved to read the position of loading point,space position and assembly relationships of lever system.Thus,the software can automatically generate lever system assembly model in CATIA.It intuitively shows the lever system deformation process,then the CATIA function was used for interference inspection to find out the lever group that may collide during the test,so as to avoid it in the process of design.In addition,the data input and output interfaces for a commercial virtual-assembly-system was developed,and was compiled into dynamic link library files.The experimental equipment of wing panel and loading lever system were built to measure transfer function.Lever groups with different connection modes,mass and lever ratio were chosen,the force signal at the excitation point and the acceleration signal at a special position of the wing panel were recorded to obtain the frequency response function curve.Superposition of the frequency-response-function curves shew that the superposition of frequency response function of single linkage and frequency response function of lever group conformed the prediction in the low frequency range,but with the increase of frequency,the deviation gradually increased,and the deviation can be reduced by reducing the mass of lever group.