轻质泡沫混凝土吸能特性及其压溃流动应力方程

轻质泡沫混凝土是一种拦阻冲出跑道飞机的重要阻滞材料，为了揭示其压缩力学性能及变形破坏机制，利用CSS4410电子万能试验机、Instron Dynatup9250落锤试验机以及VHS 8800高应变率系统，对密度为0.21、0.31 g/cm 3的轻质泡沫混凝土，在压缩速度2×10 -5~12 m/s范围内的力学特征、破坏及变形机理等进行了系统研究，用理论模型对不同压头面积下的挤压强度进行预测，并建立挤压压溃流动应力方程。结果表明：此材料变形、压溃碎化到压实过程中，以压溃前驱界面运动为特征，变形具有显著的局部失稳特性；压缩强度依赖密度和冲击速度；所采用的理论模型可以较准确的预测不同压头面积下的挤压强度；所建立的压溃流动应力方程可以很好的描述材料的压缩挤压力学特性。

Energy-absorbing Properties and Crushing Flow Stress Equation of Lightweight Foamed Concrete

Lightweight foamed concrete is a new arresting material for arresting overrun aircraft. To reveal its compression properties and mechanism of deformation and destruction, a study on lightweight foamed concrete with different density, 0.21 and 0.31 g/cm 3 respectively, has been carried out. Experiment system include CSS4410 electronic universal testing machine and Dynatup9250 drop-hammer testing machine and VHS8800 high strain rate system. Then, extrusion strength under different indenter area is predicted with a theoretical model, and a crushing flow stress constitutive equation is proposed. The results show that it is characterized by the movement of crushing driving interface during the process of deformation, crush to compaction of the material, and the deformation is notably in local. The compression strength is relevant to density and impact velocity. Moreover, theoretical model can predict the extrusion strength under different indenter area exactly, and the crushing flow stress equation can describe mechanic properties of compression well.