外载荷作用下水泥砂浆复合材料中的弹性波波速分析

为研究水泥基复合材料中弹性波频散特性,应用主频分别为50kHz、300kHz和1MHz三种声波探头,对钢纤维体积含量分别为0.5%、1.0%和3.0%的三种钢纤维增强水泥砂浆试件进行了单轴压缩下的弹性波测试实验。结果表明:在加载初始阶段,P波波速随着载荷增大而明显增大,但这种增大趋势逐渐减弱,并达到一个较稳定的值。随着钢纤维体积含量增加,波速有增大趋势。S波具有类似趋势,但其增幅比P波小得多。三种材料均表现出一定的频散效应。为消除材料在初始加载过程的非线性特性影响,采用了相对波速的方法,并讨论了相对波速的频散效应。结合多组份未胶结模型和Hashin-Shtrikman上限模型,应用一种无量纲理论模型,对比分析了弹性波波速频散规律。

Analysis of Elastic Wave Velocity in Steel Fiber Reinforced Cement Mortar Composite Subjected to External Compression Loading

In order to study the frequency dispersion characteristics of elastic wave in cement matrix composite,adopting three kinds of acoustic probe with main frequency of 50kHz,300kHz and 1MHz respectively,elastic wave measurement was carried out for steel fiber reinforced cement mortar specimens with three different steel fiber volume contents of 0.5％,1.0％ and 3％ and subjected to uniaxial compression.Results show that on the initial stage of loading,with the increase of loading,P wave velocity increases obviously.But this trend is gradually weakening and finally P wave velocity achieves a relatively stable value.With the increase of steel fiber volume content,wave velocity presents increasing trend.S wave has similar trend,but its increase amplitude is much smaller than that of P wave.All three kinds of material present certain frequency dispersion.In order to eliminate material nonlinear effect in the initial loading process,the relative velocity was adopted,and the frequency dispersion effect of relative velocity was discussed.Combining with multi component unconsolidated model and Hashin-Shtrikman upper bound model and adopting a theoretical dimensionless model,elastic wave velocity frequency dispersion was comparatively analyzed.