混凝土结构受载损伤破裂过程伴随着声发射(AE)现象,其损伤的积累会影响AE信号能量的衰减效应。为进一步探究材料损伤和AE信号能量衰减之间的关联模式,进而利用能量衰减规律对混凝土损伤程度进行量化表征,对钢筋混凝土梁三点弯曲破坏的全过程进行了AE监测,并根据损伤定位结果实时计算了能量衰减系数,通过衰减系数的时程变化确定了混凝土损伤发展的三个阶段,提出了基于AE能量衰减系数的混凝土损伤评估方法。试验结果表明,该方法可实时量化评估混凝土试件的损伤状态,并对试件宏观裂纹出现后承载模式的转变进行预警。

Acoustic emission (AE) phenomenon occurs with damage process of loaded concrete structures, and the accumulation of damage affects the energy attenuation effect of AE signal. To furtherly explore the correlation mode between material damage and AE signal energy attenuation, and then use the energy attenuation law to quantitatively characterize the degree of concrete damage, AE monitoring was carried out for the entire failure process of reinforced concrete beams under three-point bending loads, and the energy attenuation coefficient was calculated in real time with the help of the damage location results. The development of concrete damage can be divided into three stages according to the time-history change of the attenuation coefficient and a method based on AE energy attenuation coefficient was proposed to assess concrete damage. The test result showed that the method can quantitatively evaluate the damage of the concrete specimens in real time, and give an early warning to the transition of the bearing mode after the macroscopic cracking of the specimen occurs.