钢纤维增强混凝土动态力学性能及HJC本构模型参数标定

Dynamic mechanical properties of steel fiber reinforced concrete and parameter calibration of HJC constitutive model

探讨了不同体积掺量钢纤维和镀铜钢纤维对混凝土动态力学性能的影响,以及标定本构模型参数对钢纤维混凝土和镀铜钢纤维混凝土的适用性。在高强混凝土中掺加0.5%、1%、1.5%体积掺量的钢纤维制备7组试件,分别进行静态力学性能试验和分离式霍普金森压杆试验(SHPB),基于静态、动态力学结果修正Holmquist-JohnsonCook(HJC)本构模型参数,并利用有限元分析软件验证HJC模型参数的有效性。结果表明,在0.5%、1%、1.5%体积掺量下,混凝土动态峰值抗压强度随纤维掺量的增加而提高。标定的HJC模型对钢纤维混凝土的动态峰值抗压强度预测效果良好,模拟得到的应力-应变曲线与SHPB试验结果大致吻合。以侵蚀准则模拟得到动态冲击试验试件破坏过程,为钢纤维混凝土的抗冲击设计提供参考。

The effects of different volumes of steel fibers and copper-plated steel fibers on the dynamic mechanical properties of concrete are explored,and the applicability of calibrated constitutive model parameters to steel fiber reinforced concrete and copper-plated steel fiber reinforced concrete is discussed.In this paper,seven groups of specimens are prepared by adding steel fibers of 0.5%,1% and 1.5% volume fraction to high-strength concrete.The static mechanical properties test and the split Hopkinson pressure bar test(SHPB) are carried out respectively.Based on the static and dynamic mechanical experimental results,the parameters of Holmquist-Johnson-Cook(HJC) constitutive model are modified,and the effectiveness of the HJC model parameters is verified by numerical simulation of the finite element analysis software.The results show that the dynamic peak compressive strength of concrete increases with the increase of fiber content at 0.5%,1% and 1.5% volume fraction.The calibrated HJC model has a good effect on predicting the dynamic peak compressive strength of steel fiber reinforced concrete,and the simulated stress-strain curve is roughly consistent with the SHPB test results.The failure process of the specimen in the dynamic impact experiment simulated by the erosion criterion provides a reference for the impact design of steel fiber reinforced concrete.