大直径SHPB实验中的高温加载技术及其应用

为研究材料的高温动态力学行为，提出一套由自主设计的温控系统和100 mm SHPB装置组成的高温SHPB实验系统，采用ANSYS软件对界面热传导及其对实验结果的影响进行了计算分析，论证了该实验技术的可靠性，并对混凝土的高温动态力学性能进行了研究。结果表明:在大直径合金钢材质SHPB装置上对混凝土等热惰性材料进行高温冲击实验，冷接触时间临界值为1.00 s，本文中提出的高温加载技术可将冷接触时间控制在0.50 s以内，实验技术可靠；同一加载速率下，随着温度从常温升到1 000 ℃，高温混凝土的动态应力应变曲线呈现出塑性变化趋势，动态抗压强度先提高后降低，动态峰值应变则不断增大。

High-temperature loading techniques in large-diameter SHPB experiment and its application

To study the dynamic mechanical properties of material at high temperatures, a new high-temperature split Hopkinson pressure bar (SHPB) system was proposed by combining a self-developed temperature-controlling system and an ordinary 100-mm-diameter SHPB system. The ANSYS software was used to analyze the interface heat transfer phenomenon and its influences on the experimental results. The reliability of the experimental technique proposed was demonstrated. And the experimental technique proposed was utilized to investigate the dynamic mechanical properties of concrete at high temperatures. The results show that for the high temperature impact tests on heat-inertia materials such as concrete using the large-diameter SHPB made of alloy steels, the critical value of cold contact time (CCT) is 1.00 s, and the CCT for the experimental technique proposed does not exceed 0.50 s, the experimental technique proposed is credible; and that at invariable loading rate with temperature increasing gradually from normal temperature to 1 000 ℃, the dynamic stress-strain curves of concrete exhibit gradually plasticity properties, the dynamic compressive strength first rises, then falls, and the dynamic peak strain rises constantly.