钢筋混凝土在冲击载荷下的动态力学性能

Dynamic Mechanical Properties of Reinforced Concrete Subjected to Shock Loading

利用一级轻气炮加载,对钢筋混凝土圆柱形靶板进行冲击压缩实验,飞片与靶板同质,由预埋的锰铜压阻传感器测量出压力-时间信号曲线。实验数据采用拉氏分析方法中的路径线法自编程序进行处理,反算出粒子速度、应变等力学参量。实验结果表明:钢筋混凝土材料的应力应变总体呈滞回特性,并具有明显的应变率相关性和波形弥散效应等动态力学性能。同时基于复合材料细观力学的方法,认为理想情况下钢筋混凝土本构关系可由混凝土材料粘弹性本构关系与一个依赖于增强钢筋材料特性的常量G的乘积确定,并假定损伤只发生在混凝土内部,给出了钢筋混凝土的损伤型动态本构关系,理论预测曲线与试验结果吻合良好。

One-stage light gas gun is used to study the dynamic mechanical properties of reinforced concrete subjected to shock loading. The material of projectile is the same as of the target. The stress- time curves are recorded by three manganin pressure transducers embedded in the target in advance. The experimental data are analyzed by self-designed program using the path line principle of Lagrangian analysis method. With the stress records, complete histories of particle velocity and strain can be obtained at any point within the gauged regions of the reinforce concrete. The result of experiment indicates that the stress-strain curves of reinforced concrete present stagnant-return properties. And some other dynamic properties can be gained, such as rate dependent, waveform dissipation and so on. Furthermore, Based on the analytical micromechanical method, the dynamic constitutive relation of reinforced is declared to multiply the viscoelastic constitutive relationship of concrete by a constant G on the assumption that the damage occurred only in the concrete. The prediction agrees with the experimental data.