不同含水率红陶土的SHPB动力学性能实验

为研究动态加载下红陶土的动态力学特性,利用分离式霍普金森压杆(SHPB)动力学试验系统,开展了含水率分别为5%、7%、9%、11%、13%和15%,冲击速度分别为6 (m·s-1)、8 (m·s-1)和10 (m·s-1),共计 18组不同含水率和冲击速度的红陶土试样测试实验,分析了不同含水率和应变率条件下红陶土的动力学特性。结果表明:随着冲击速度的增大,红陶土具有明显应变率效应;在冲击荷载作用下,红陶土的动态应力–应变关系曲线随加载应变率的不同呈现2种曲线类型,分别为脆-塑性破坏和脆性破坏,随着应变率的增加,红陶土破坏过程由塑-脆性破坏逐转变为脆性破坏;在冲击速度单一因素影响下,红陶土的抗压强度、动态弹性模量均随应变率的增大而增加,并随着含水率的增大先减小后增大。

Experimental study on SHPB dynamic properties of red clay with different water content

In order to study the dynamic mechanical properties of red clay under dynamic loading, the separated Hopkinson pressure bar (SHPB) dynamic test system was used to carry out water content of 5%, 7%, 9%, 11%, 13% and 15%, and impact velocities of 6(m·s-1), 8(m·s-1) and 10(m·s-1), respectively. A total of 18 groups of red clay samples with different water content and impact velocity were tested to analyze the dynamic characteristics of red clay under different water content and strain rate conditions. The results show that the clay has an obvious strain rate effect with the increase of impact velocity. Under impact load, the dynamic stress-strain curve of lattice-clay presents two types of curves with different loading strain rates, namely, brittle-plastic failure and brittle failure. With the increase of strain rate, the failure process of lattice-clay gradually changes from plastic-brittle failure to brittle failure. Under the influence of single factor of impact velocity, the compressive strength and dynamic elastic modulus of terracotta increase with the increase of strain rate, and first decrease and then increase with the increase of water content.