单轴压缩作用下CFST柱的声发射特征

通过对不同配筋率和不同壁厚钢管混凝土(CFST)柱进行单轴压缩声发射试验，对比分析了各试件破坏全过程的声发射信号特征.试验结果表明:试件的整个破坏过程可分为弹性段、弹塑性段、强化段和失效段四个阶段，声发射特征参数变化与试件破坏过程表现出较好的对应关系.声发射累积能量和累积撞击数均随荷载的增加而稳步增加;b值经历了缓慢上升、平稳波动、迅速下降的变化，反映了试件内部裂纹的逐步扩展情况;通过对声发射RA值、AF值分析可知，钢管混凝土柱的破坏过程既产生拉伸型裂纹又产生剪切型裂纹，随着荷载的增大，破坏中剪切型裂纹所占比例逐渐增多.研究表明声发射技术可以有效监测轴压下钢管混凝土柱的损伤状态.

Acoustic Emission Characteristics of CFST Columns Under Uniaxial Compression

Based on the uniaxial compression acoustic emission (AE) test of concrete-filled steel tube (CFST) columns with different reinforcement ratio and wall thickness， the AE signal characteristics of each specimen in the whole failure process were analyzed. The test results show that the entire failure process of the specimen can be divided into four stages: elastic section， elastoplastic section， strengthening section and failure section. The change of AE characteristic parameters shows a good corresponding relationship with the failure process of the specimen. The AE cumulative energy and AE cumulative impact number rise with the load increases. The b value has experienced a slow rise， steady fluctuation， and rapid decline， reflecting the gradual expansion of the internal cracks of the specimen; through the analysis of the RA value and AF value of AE， it can be seen that the failure process of the CFST column generates both tensile and shear cracks. With the increase of load， the proportion of shear crack in failure increases gradually. The results show that the AE method can effectively monitor the damage status of CFST columns under uniaxial compression.