Liu Kaixuan, Chen Zhenfu, Tao Qiuwang, Wu Dan, Wu Qiongfang, Zou Pinyu, Wang Minghui, Li Yangzi
School of Civil Engineering, University of South China, Hengyang 421001, China.
China Nuclear Industry Key Laboratory of High-Performance Concrete, University of South China, Hengyang 421001, China.
Materials (Basel). 2024 Nov 27;17(23):5804. doi: 10.3390/ma17235804.
To study the dynamic compressive mechanical properties of concrete with different aggregates (limonite and lead-zinc ore), a dynamic mechanical experiment was carried out by the Φ 100 mm SHPB equipment. Based on the coupling of the finite difference method (FDM) and the discrete element method (DEM), a three-dimensional numerical model was constructed. The effects of various strain rates and aggregate types on the dynamic mechanical properties of concrete, the dynamic increase factor (DIF), and the dynamic impact damage process were analyzed and discussed. The results show that both types of concrete have a significant strain rate strengthening effect. The dynamic compressive strength, peak strain, and DIF of the two types of concrete gradually increase with the increasing strain rate. The DIF and dynamic compressive strength growth of lead-zinc ore concrete was greater than that of limonite concrete, and the strain rate sensitivity of lead-zinc ore concrete was stronger than that of limonite concrete. The constructed three-dimensional coupling model can better simulate the experimental process, and the stress-strain curves and damage patterns show good agreement with the experimental results. The relative errors between the calibration results of the microscopic parameters and the experiment values are all within 1%.
为研究不同骨料（褐铁矿和铅锌矿）混凝土的动态抗压力学性能，采用Φ100mm SHPB装置进行了动态力学试验。基于有限差分法（FDM）与离散元法（DEM）的耦合，构建了三维数值模型。分析和讨论了不同应变率和骨料类型对混凝土动态力学性能、动态增长因子（DIF）以及动态冲击损伤过程的影响。结果表明，两种类型的混凝土均具有显著的应变率强化效应。两种混凝土的动态抗压强度、峰值应变和DIF均随应变率的增加而逐渐增大。铅锌矿混凝土的DIF和动态抗压强度增长幅度大于褐铁矿混凝土，且铅锌矿混凝土的应变率敏感性强于褐铁矿混凝土。所构建的三维耦合模型能够较好地模拟试验过程，应力-应变曲线和损伤模式与试验结果吻合良好。微观参数校准结果与试验值之间的相对误差均在1%以内。
