Experimental Investigations Of Dynamic Characteristics Based On The High Elastic Coupling Of New Composite Material

High-elastic couplings are playing more and more important part in the power unitof the modern mechanical systems, as not only to assume power and motiontransmission, but also to compensate for shaft misalignment and control devices’vibration and noise. However, the commonly used metal flexible couplings are small-damp, high cost and maintenance difficulties. The rubber elastic element，which non-metallic flexible couplings commonly used，is easy to aging, poor oil resistance andhigh/low temperature resistance. The new engineering composite BTG plastic alloy isvery suitable for coupling manufacture material of high flexibility couplings, while it isnot only easy to process, but also has well shock absorption and cushion, friction andwear properties and resistance to fatigue wear performance.However, this new BTG plastic alloy material as the elastic component materials ofthe coupling is the first case. It has not being known its dynamic characteristics andproperty parameters of the coupling. By the dynamic experiments, this paper studied thedynamic characteristics of the coupling in the different vibration frequency andvibration amplitude of the radial, axial and torsional vibration, and its system model.This study includes the following aspects:①Discussed the four mathematical models of hysteretic nonlinear system used inthe project, and the scope of these models’ characteristics were analyzed. Thepolynomial hysteresis model was selected, because expression of its physical meaningis very clear, simple, good adaptability to the experimental data, and well systemidentification.②Then this paper introduced the dynamic characteristics of experimental subjects,the structure of the experimental apparatus, experimental programs, observation of theoriginal signal measurement and analysis of the pretreatment process.③Numerical problems were solved in the analysis of experimental data in theMATLAB software, such as smooth the noise, the area calculation of nonlinearhysteretic curve, the differential transformation of the time-domain sampling signal andcalculation methods of curves and surfaces fitting.④Dynamic experimental results and system macro trends were understood byanalysis of hysteresis curve drawn with signal processing results. The experimental curve-fitting results show that the polynomial hysteresis model is excellent to identifyfor this high-flexible coupling dynamic experiments.⑤Parameter-fitting values of each parameter in the polynomial model werecalculated for each condition in each test group. Each parameter’s characteristics ofchanges with amplitude and frequency were analyzed. Then, their mathematicalexpressions were submitted, and the undetermined coefficients of mathematicalexpression were identified.Dynamic modeling to the coupling was completed. The mathematical expression ofthe stiffness components and damping components reflect not only the stiffness anddamping’s characteristics of the system, but also characteristics they change with thedisplacement amplitude and frequency. As the system vibration amplitude andfrequency known, the model can also be a good description of nonlinear hysteresiscurve to the system.