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采用锤击法,对梯形轨道系统(简称梯轨)进行动力特性试验。利用变时基传递函数细化分析方法,解决力信号时域波形精度与加速度信号频率分辨率之间的矛盾,提高低频脉冲频响分析精度。根据锤头材料的锤击特性和试验研究的频率范围,分别选择尼龙和钢制锤头进行梯轨模态和减振特性试验研究。结果表明:梯轨的低阶模态分布比较密集,基频为48.6Hz,前3阶模态的阻尼比较高,1阶阻尼比最大,达到6.64%;梯轨的工作频率约为50Hz,在梯轨工作频率之上1/3倍频程中心频率处,传递损失不随锤击力的大小而变化,梯轨的振动衰减系数为常数;梯轨具有较高的减振作用,在0～1000Hz频段传递损失在45dB左右。
Using hammering method, the trapezoidal rail system (referred to as ladder rail) for dynamic test. The time-base transfer function refinement analysis method is used to solve the contradiction between the waveform accuracy of the force signal and the frequency resolution of the acceleration signal and improve the accuracy of the analysis of the frequency response of the low-frequency pulse. According to the hammering characteristics of the hammerhead material and the frequency range of the experimental research, nylon and steel hammerheads were respectively selected to study the modal and damping characteristics of the ladderway. The results show that the low-order modal distribution of the ladder track is relatively dense, the fundamental frequency is 48.6Hz, the damping ratio of the first three modes is high, the damping ratio of the first order is 6.64%, and the operating frequency of the ladder track is about 50Hz. At the center frequency of 1/3 octave above the operating frequency of the ladder rail, the transmission loss does not change with the magnitude of the hammering force, and the attenuation coefficient of the ladder rail is constant. The ladder rail has a high damping effect. At 0-1000 Hz Band transmission loss around 45dB.