基于声发射技术的混凝土梁破坏损伤过程的试验研究

Experimental Study of Acoustic-Emission-Technique-Based Detection of Damage in Concrete Beams

对不同特征混凝土简支梁进行了加载破坏的声发射试验,通过有限元计算确定荷载范围以及不同梁的加载应力与应变变化规律。试验加载过程中测试梁上控制点处的应变及声发射信号,通过应力变化及外观观察,记录梁的受力状态和裂纹产生的条件,通过分析试验全过程中的声发射信号能量时程图,得到简支梁破坏过程中的能量变化特征、频率分布范围及特点,以及不同特征简支梁破坏过程中声发射能量参数的变化规律。试验表明,声发射技术监测混凝土梁的状态及损伤破坏有一定的优势。

The acoustic emission tests for loading damage of simple-supported concrete beams with different characteristics are conducted,upon the basis of which the load range and the change laws of the loading stress and the strain of different beams are determined by means of the finite element method.The strain and acoustic emission signals in the control points of the beam are collected during the loading process.By the stress changes and the appearance observation,the forced state and the conditions of cracks are recorded.The characteristics of energy change and the frequency range distribution during the beam damage are concluded by energy-time graphs,and the change laws of the energy parameters are revealed,too.The experimental results show that the acoustic emission technique has some advantages in monitoring the state and the damage of concrete beams.