薄板类木质材料弹性模量的动态测定

Measuring modulus of elasticity for thin wood composites using a dynamic method

传统的材料弹性模量测定方法都是对材料试件进行静态变形试验,测定过程复杂、消耗时间长。本文以快速测量薄板类木质材料弹性模量为目标,探讨了一种基于悬臂梁自由振动原理的动态无损快速测定方法,研制出1台测量装置样机。首先用垂直悬臂夹持薄板木质材料试件上端,然后对其自由端施加1个初始变形,使其自由振动起来。采集试件振动信号,分析计算出振动的第一阶固有频率和振幅对数减缩,进而计算出试件的动态性能。测定效果表明:测量装置样机达到了研发目的,能快速测量试件的动态弹性模量。

Traditional testing for modulus of elasticity（MOE） of materials uses a static test method,which is long and complicated.To provide a rapid and non-destructive evaluation of MOE for small samples of thin wood composites,we discussed the fundamental theories of cantilever-beam vibration for MOE measurements and developed a testing device for cantilever-beam vibration.The equipment applies a known displacement to the free end of a vertical cantilever beam,releases the beam into its natural first mode vibration and records displacement as a function of time.The resonant frequency and amplitude attenuation is then used to calculate the dynamic properties of the samples.The testing results show that the device can measure the dynamic MOE of the samples quickly and efficiently.