The Dynamic Characteristics Of The Excitation System Optimization Design

This thesis intends to extend the frequency range of a shaker, minimize the impact of the additional mass and stiffness on the assessment results and make the frequency property of a shaker flat.Firstly, a calculating model of exciter with zero load is built. The analysis of the model leads to the findings that the frequency range of a shaker is mainly determined by its skeleton and supporting spring plate, of which the former has an impact on the upper bound of the frequency width and the latter sets its lower limit; that the supporting spring plate also influences the flatness of the frequency property. Secondly, a calculating model of exciter with load is built. The impact of the additional mass and stiffness on the assessment results is analyzed. Thirdly, based on two typical shaker, HEV-200(single-moving-coil-structured) and HEV-500(double-moving-coil-structured), using the model test with a combination of the finite element analysis, this thesis establishes a finite element dynamical model as a sound model for further dynamic optimization. Through analysis the causes of the peak-trough of the frequency curve of the HEV-500 shaker is found, and a shaker of single-skeleton, double-coil structure style is proposed. Consequently using the optimizing mode of MSC/Nastran, the thesis optimizes the shape design of a skeleton with the aim to get the frequency width of 5kHz and discusses the problems encountered; it also optimizes the design of the supporting spring plate using carbon fiber/resin matrix T300/QY8911 composites with laminated structure; it adopts the viscoelastic damping materials to counteract the vibration of the spring plate itself and effecting eliminates the peaks in the frequency range.