纵向共振法测量粘弹性材料力学参数

摘要

利用虚拟仪器测试系统,对粘弹性材料力学参数进行纵向共振法测量.用激振器产生多周期正弦信号,激励棒状试样纵向振动,测量激振器输出端和材料自由端的加速度比值.通过共振频率及共振频率处加速度比的幅值,可以计算样本的杨氏模量和损耗因子.采集信号经过多次时域平均,可在最大程度上提高测试的信噪比.系统的测量结果与商用粘弹性仪结果是一致的.%Based on virtual instrument measuring system, mechanical parameters of the viscoelastic material are measured in longitudinal vibration. One end of the bar is excited by a periodic sinusoidal signal with vibrator, while the other end is allowed to move freely. After which, the amount of acceleration of these two ends are measured using the transducer. At resonant frequency, Young's modulus and loss factor can be calculated using the amplitude of acceleration ratio between the driven end and the free end. Besides this, the sampled signals are averaged in several times, which can improve SNR highly. The measuring results agree well with that of commercial viscoelastic instrument.