钢管钢纤维高强混凝土抗冲击压缩性能的试验研究与数值模拟

遮弹层的建成及优化对防护工程的发展尤为重要。钢管钢纤维高强混凝土蜂窝遮弹层是一种具有高强抗力的新型遮弹层,文章对其组成构件钢管钢纤维高强混凝土进行霍普金森压杆(SHPB)动态力学性能试验,并借助动力有限元分析软件LSDYNA进行数值模拟。冲击压缩试验中,试件的钢纤维掺量分别为0%、0.5%、1.0%、1.5%,钢管壁厚分别为2mm、3mm。结果表明钢管钢纤维高强混凝土具有应变率强化效应,应变率越高,试件的动态抗压强度越大。当气压为1.0 MPa时,壁厚3mm、钢纤维掺量1.5%的试件强度达258.3 MPa。与钢纤维高强混凝土相比,钢管钢纤维高强混凝土的抗冲击压缩性能更好,动态抗压强度最大增幅达35.4%,且具备承受多次冲击压缩作用的能力。数值模拟与试验结果吻合度高,表明数值模拟方法具有可行性。

Experimental Study and Numerical Simulation on the Impact Compression Performance of Steel Fiber Reinforced High Strength Concrete-filled Steel Tube

The construction and optimization of bursting layer plays a significant role in the development of defensive fortifications. The honeycomb bursting layer made of steel fiber reinforced high strength concrete-filled steel tube is a new type of bursting layer with high impact resistance. In this paper, a dynamic mechanical test and a numerical simulation for a lab-prepared steel fiber reinforced high strength concrete-filled steel tube were conducted by using a split Hopkinson pressure bar (SHPB) set-up and the kinetic finite element analysis software LS-DYNA, respectively. The steel fiber content and tube thickness of the high strength concrete filled steel tubes for impact compression test were set at 0%, 0.5%, 1.0%, 1.5% and 2 mm, 3 mm, respectively. The results showed that steel fiber reinforced high strength concrete-filled steel tube exhibits strain rate strengthening effect, as higher strain rates corresponded to greater dynamic compressive strengths. When the air pressure was 1.0 MPa, the specimen with 3 mm tube thickness and 1.5% steel fiber content achieved a dynamic compressive strength of 258.3 MPa. Compared with steel fiber reinforced high strength concrete, the steel fiber reinforced high strength concrete filled-steel tube possesses better impact compression perfor-mance, as the maximum relative increase of dynamic compressive strength reached 35.4%, also the ability to withstand repeated impact compressions. The numerical simulation coincided well with the experimental results, which confirmed the feasibility of the numerical simulation method.