预应力钢筋混凝土梁破坏过程的声发射特性实验研究

利用全波形声发射技术记录了预应力钢筋混凝土梁在3点弯曲荷载下整个破坏过程的声发射信号,并在研究了声发射累计能量随时间变化关系曲线的基础上,采用谱分析对声发射全波形数据进行了分析和处理。以全波形声发射信号的能量分布特性为依据,通过对时域和频域内信号的振幅、频率特征和构件破坏过程的比较,初步得出了预应力钢筋混凝土梁破坏过程的声发射信号的参数特性,发现全波形声发射信号能够实时反映预应力混凝土梁破坏过程中的特征信息。

Study on the AE Characteristics of Cracking Process in Prestressed Concrete Beams

A series of prestressed concrete beams were loaded at three points subjected to bending until failure. The waveform acoustic emission signals were recorded. Crack initiation and propagation due to bending were monitored and compared with observation. Based on the relationship between the cumulative en- ergy of acoustic emission and time, the waveform acoustic emission signals of different destruction states was picked up and spectral analysis was carried out. According to the value of the energy amplitude of waveform acoustic emission and the comparison of the amplitude and frequency of waveform acoustic emission signals in time domain and frequency domain, different damage stages of the prestressed concrete specimens until failure were divided, and the parameter properties of prestressed concrete specimens were picked up. The research shows that waveform acoustic emission signals can be used to find the characteristics of the different damage stages of prestressed concrete beams under loading in real time.