分层介质动态力学性能的实验研究

采用Φ75mm分离式霍普金森压杆实验装置,对由普通混凝土与泡沫混凝土组合的分层介质的动态力学性能进行了研究。结果表明,应力波通过普通混凝土时的衰减仅为其原来峰值的5%~10%,应力波通过泡沫混凝土时其峰值衰减为原来的1/5。由此说明在含泡沫混凝土与普通混凝土的分层介质中,泡沫混凝土提供削波与延缓应力波作用时间的作用,普通混凝土则为其提供较高强度。通过对分层介质应力衰减和动量变化的分析表明,分层介质在动态力学行为上表现为较大的塑性和应变率相关性,其应力衰减主要取决于泡沫混凝土材料。

EXPERIMENTAL RESEARCH ON DYNAMIC PROPERTIES OF LAYERED MEDIUM

The dynamic properties of layered medium prepared by common concrete and foam concrete were researched with Split Hopkinson Pressure Bar(SHPB) of 75mm in diameter.The results showed that stress attenuated only by 5%～10% of its peak value when stress wave penetrated common concrete,but by 80% of its peak value when penetrated foam concrete.Regarding the layered medium containing common concrete and foam concrete,the results suggested that foam concrete could weaken stress wave and delay the time that stress wave affected the layered medium,but common concrete could strengthen the medium.Stress attenuation and momentum variance of layered medium were measured with PVDF sensors,which gave the facts that layered medium was sensitive to strain rate with large plastic deformation,and stress attenuation of layered medium mainly affected by foam concrete.