一种准零刚度车载隔振系统的设计与试验研究

针对车辆行驶工况环境以及振动频率,研制了一种空间占比小、安装方便的准零刚度(quasi-zero-stiffness,QZS)车载隔振系统。将垂向弹簧与两个对称的负刚度结构并联,负刚度机构用于刚度校正,通过静力学特性分析,初步确定了系统在平衡位置具有准零刚度的参数条件,在推导中引入了加工误差系数,分析了加工误差系数对系统准零刚度的影响机理。建立了系统非线性动力学方程,采用平均法求解了系统在车体简谐位移激励下的动力学响应,分析了系统参数和激励幅值对位移传递率的影响。在此基础上,设计制作了准零刚度隔振系统,进行了不同激励幅值、激励频率下的测试,得到了实测的位移传递率幅频响应曲线,并与理论计算结果进行了比较。另外,还通过TruckSim/Simulink联合仿真进行了车载随机激励工况仿真分析。研究表明,试验与理论结果吻合较好,验证了准零刚度隔振系统理论建模和分析方法的正确性。准零刚度的起始隔振频率在1.4 Hz左右,优于线性系统的起始隔振频率2.9 Hz。与车体相应相比,隔振后的位移响应均方根值降低80%以上,加速度均方根值降低90%左右,且稳态时准零刚度隔振系统的稳定性较好,具有良好的隔振性能。

Design and test of a quasi-zero-stiffness vehicle vibration isolation system

Considering the harmfulness of driving environment and the vibration frequency of vehicle-borne precision instruments,a quasi-zero-stiffness(QZS)vehicle vibration isolation system with small space proportion and convenient installation was designed and manufactured.A vertical spring was connected in parallel with two symmetrical negative stiffness structures which were used for stiffness calibration.Based on a static analysis,the parameter conditions for the system with QZS in equilibrium position were preliminarily determined.In the derivation,a machining error coefficient was introduced,and its influence on the QZS of the system was analyzed.The nonlinear dynamic equation of the system was established and the average method was used to get the dynamic response of the system under harmonic displacement excitations of the vehicle body.The influences of the system parameters and the excitation amplitude on the displacement transfer rate were analysed.On this basis,a QZS vibration isolation system was designed and manufactured,and tests were carried out under different excitation amplitude and frequency.The measured amplitude frequency response curve of the displacement transfer rate was compared with the theoretical calculation results.In addition,a co-simulation by Trucksim/Simulink was carried out under vehicle random excitation condition.The research shows that the experimental results are in good agreement with the theoretical results,which verifies the correctness of the theoretical modeling and analysis method for the QZS vibration isolation system.The initial vibration isolation frequency of QZS is about 1.4 Hz,which is better than that of a corresponding linear system by 2.9 Hz.The RMS value of displacement response of the vehicle body with the vibration isolation unit is reduced by more than 80%,and the acceleration is reduced by about 90%.The stability of the quasi-zero stiffness vibration isolation system in steady state is rather good,which shows it has good vibration isolation performance.