碱式硫酸镁水泥混凝土的冲击压缩性能

Impact Compressive Properties of Basic Magnesium Sulfate Cement Concrete

关键词:  碱式硫酸镁水泥混凝土  分离式霍普金森压杆  应变率效应  动态增强因子  数值模拟

Key words:  basic magnesium sulfate cement concrete（BMSCC）  split Hopkinson pressure bar  strain rate effect  dynamic increase factor  simulation

摘要:

采用75mm分离式霍普金森压杆测试了碱式硫酸镁水泥混凝土（BMSCC）的力学性能，并借助Ls Dyna软件和Holmquist Johnson Cook（HJC）模型，模拟了BMSCC的动态冲击力学响应.结果表明：BMSCC是典型的率相关性材料，具有明显的应变率增强效应，其冲击压缩强度随着应变率的提高而增大，动态增强因子与应变率的对数呈线性关系.通过数值模拟确定了HJC模型的21个参数，其中冲击压缩强度和峰值应变的模拟相对误差分别为-39%～09%和-100%～32%，模拟效果较好.

Abstract:

The mechanical properties of basic magnesium sulfate cement concrete(BMSCC) was tested using the 75mm diameter split Hopkinson pressure bar. The finite element software Ls Dyna and Holmquist Johnson Cook（HJC） model were used to simulate the mechanical response of BMSCC under impact loading. The results show that BMSCC is a typical rate dependent material with the pronounced strain rate hardening effect and its impact compressive strength increases with increasing strain rate. As a parameter characterizing the dynamic characteristics of brittle materials, dynamic increase factor is linearly related to the logarithm of strain rate. By using Ls Dyna software to simulate the impact compression process, 21 parameters of the HJC model are determined. The relative errors of impact compressive strength and peak strain are -39%09% and -100%32%, respectively. The simulation effect is quite satisfactory.