"S" Shape Test Specimen CNC Side Milling Vibration Analysis And Machining Surface Quality Research

At present, the thin wall parts have been widely used in the aerospace field in orderto reduce the total weight of aircraft. Because its characteristics such as complicatedshape, large amount of material removed and the weak relative stiffness, there are someproblems appeared in the processing, include deformation and vibration, etc, can easilycause difficult process and poor processing quality. So, the research ofthe problemsabout aviation thin-wall parts’ processing surface qualityis very necessary."S" shape test specimen is used to test the processing performance of five-axisCNC machine tool, which put forward by AVIC Cheng Du Aircraft Industrial (GROUP)CO. LTD. It ownedcharacteristics with thin wall, variable curvature and open and closeangle conversion. This paper using the finite element analysis and set up processingsystem dynamics model to research the problems appeared in the processing.Includedeformation, system vibration and surface quality, etc.The main content as follows:1."S" shape test specimen normal deformation, normal stiffness and modalparameters calculated. Using the finite element software ANSYS. Get its normalstiffness, normal deformation and modal parameters and verification the result’saccuracy by Modal knock experiment.2.The machine tool comprehensive stiffness and vibration analysis under differentmotion. By using multi-body dynamics theory, etc, calculation the machine tool’scomprehensive stiffness along "S" shape test specimen’s surface norm under differentprocessing attitude when machining "S" shape test specimen. Obtain the functionrelationship about vibration displacement respectively with workpiece stiffness andmachine tool’s comprehensive stiffness through establish vibration model.3.Workpiece surface waviness analysis. Through the analysis of the self excitedvibration of machining system, research the vibration frequency components and theinfluence mechanism between vibration frequency and surface waviness.4.Workpiece surface quality experimental validation. Carry out surface wavinessmeasurement experiment, surface micro display experiment and profile errormeasurement experiment. To verify the theory research by contrast the experimental results and the theoretical analysis results.Through the aboveresearch content, this paper got the vibration characteristic of "S"shape test specimenand machine tool system. And through the experiment, has beenclear about the influence mechanism between important factors and surface wavinessand puts forward the waviness measurement condition of "S" shape test specimen.Provide reference frame for thin wall parts machining deformation and surface wavinesscontrol and evaluation of machining performance of different machine tool.