橡胶混凝土冲击压缩性能的试验研究和数值模拟

Experimental study and numerical simulation of shock compression performance of rubberized concrete

采用分离式霍普金森压杆装置对橡胶掺量分别为5%、10%、15%、20%,橡胶粒径为0.18 mm、1.29 mm、2 mm的12组橡胶混凝土试件进行4种应变率下的冲击压缩试验研究,得到了每一组试件在4种应变率下的应力-应变曲线.试验结果表明:随着应变率的增加,橡胶混凝土的峰值应力、动力增长因子也随之增大,橡胶掺量对橡胶混凝土的峰值应力和动力影响因子的影响与应变率一致,掺入的橡胶粒径越大,橡胶混凝土的峰值应力越大但是动力增长因子却呈减小趋势;橡胶掺量在10%左右时,橡胶混凝土能够取得较好的韧性和变形能力.参考试验结果,在经典H-J-C混凝土本构模型的基础上,利用有限元软件ANSYS/LS-DYNA进行数值模拟,得到了橡胶混凝土H-J-C本构模型的材料参数.

Twelve groups of rubberized concrete samples with different rubber content of 5 %,10 %,15 %,and 20 %,rubber particle size of 0.18 mm,1.29 mm and 2 mm were tested in the shock compression experiment under four kinds of strain rates by using Split-Hopkinson Pressure Bar,and four stress-strain curves of every set of specimen were obtained.The experimental results show that with the increase of strain rate,the peak stress of rubberized concrete and dynamic growth factor also increase;the influence of rubber content on the peak stress and dynamic growth factor is in accordance with strain rate;the larger the particle size of the rubber,the greater the peak stress of the rubber concrete,but the dynamic growth factor is actually decreasing.When the rubber content is about 10 %,rubberized concrete can achieve good toughness and deformation.Based on the classical H-J-C concrete constitutive model,taking the finite element software ANSYS/LS-DYNA for numerical simulation,material parameters of rubberized concrete H-J-C constitutive model are obtained.