温度对地下结构中声发射源定位精度的影响

通过声发射实验探讨温度对声发射定位精度的影响.采用空心半球形试件模拟常见地下结构.在火焰加热过程中,以恒定频率的脉冲信号作为声发射源,采集各传感器接收到的声发射信号,比较不同温度下的定位精度.结果表明,声发射定位误差在加热初期和加热中期基本相同.在加热后期,由于裂纹的出现,声发射的定位误差急剧增大.这为减少由温度变化引...

Influence of temperature on acoustic emission source location accuracy in underground structure

An acoustic emission (AE) experiment was carried out to explore the AE location accuracy influenced by temperature. A hollow hemispherical specimen was used to simulate common underground structures. In the process of heating with the flame, the pulse signal of constant frequency was stimulated as an AE source. Then AE signals received by each sensor were collected and used for comparing localization accuracy at different temperatures. Results show that location errors of AE keep the same phenomenon in the early and middle heating stages. In the later stage of heating, location errors of AE increase sharply due to the appearance of cracks. This provides some beneficial suggestions on decreasing location errors of structural cracks caused by temperature and improves the ability of underground structure disaster prevention and control.