中高应变率下沥青混凝土动力增长系数研究

发布时间：2018-09-05 17:24

【摘要】：为研究沥青混凝土材料在强动载条件下的动态性能,采用液压伺服试验机和霍普金森压杆(SHPB)对沥青混凝土进行了不同应变率下的压缩试验,得出了中高应变率下沥青混凝土材料的动力增长系数(DIF)和材料的动态应力-应变关系曲线.运用考虑应变率效应的弹塑性损伤模型对沥青混凝土的SHPB试验进行模拟,并通过室内试验确定本构模型中的关键参数,如强度面曲线和损伤因子等.结果表明:采用液压伺服仪和SHPB可以有效地得出沥青混凝土在中高应变率下的动力增长系数,沥青混凝土抗压强度随着应变率的提高而增加;采用室内试验可以快速准确地确定弹塑性本构模型中的相关参数,用以表述沥青混凝土的应力-应变关系;当数值模拟中采用SHPB试验中获取的动力增长系数时,将导致惯性效应的重复,故对沥青混凝土材料进行高应变率下数值模拟时,应不考虑SHPB试验中由于环向惯性效应所引起的那部分动力增长系数,即需要对SHPB试验所得的动力增长系数做修正.
[Abstract]:In order to study the dynamic performance of asphalt concrete under the condition of strong dynamic load, the compression tests of asphalt concrete at different strain rates were carried out by using hydraulic servo testing machine and Hopkinson compression bar (SHPB). The dynamic growth coefficient (DIF) and the dynamic stress-strain curves of asphalt concrete materials at medium and high strain rates are obtained. The elastoplastic damage model considering strain rate effect is used to simulate the SHPB test of asphalt concrete. The key parameters of the constitutive model, such as strength surface curve and damage factor, are determined through laboratory tests. The results show that the dynamic growth coefficient of asphalt concrete under medium and high strain rate can be obtained effectively by using hydraulic servo instrument and SHPB. The compressive strength of asphalt concrete increases with the increase of strain rate. The relative parameters in the elastoplastic constitutive model can be determined quickly and accurately by indoor test, and the stress-strain relationship of asphalt concrete can be expressed. When the dynamic growth coefficient is obtained by using SHPB test in numerical simulation, This will lead to the repetition of inertial effect. Therefore, in the numerical simulation of asphalt concrete materials at high strain rate, the partial dynamic growth coefficient caused by the toroidal inertia effect in SHPB test should not be taken into account. That is, the dynamic growth coefficient of SHPB test needs to be modified.
【作者单位】：北京工业大学城市与工程安全减灾教育部重点实验室;上海工程技术大学城市轨道交通学院;
【基金】：国家重点基础研究发展计划(973计划)资助项目(2015CB058003) 北京市自然科学基金资助项目(8172010)~~
【分类号】：U414

【相似文献】