腐蚀钢管损伤特性的声发射试验研究

Experimental study on damage characteristics of corroded steel pipes by acoustic emission

钢管腐蚀损伤的主要表现为萌生裂纹、钢管产生局部皱曲。对钢管的损伤程度进行有效评估的方法之一是找出裂纹萌生的规律。本试验的研究对象为直径700 mm、壁厚5 mm、高260 mm的Q235钢管试件,采用声发射技术对腐蚀后的钢管试件进行轴压实时检测。通过建立声学参数(累计振铃数和幅度值)与钢管试件损伤程度的关系,得到钢管腐蚀损伤后产生的裂纹扩展规律和起裂荷载值。通过分析加载点位移与声学参数的关系曲线呈现出不同变化特征,检测出钢管损伤的一般位置和测定起裂荷载的确切数值p。试验结果为进一步研究钢管试件损伤机理提供了一定依据。

The corrosion damage of steel pipe is mainly manifested as crack initiation and local wrinkles.One of the effective methods to evaluate the damage degree of steel pipe is to find out the law of crack initiation.The research object of this experiment is Q235 steel tube specimen with diameter of 700 mm,wall thickness of 5 mm and height of 260 mm.Acoustic emission technology is used to detect the axial compaction of corroded steel tube specimen.Establishing the relationship between acoustic parameters(cumulative ringing number and amplitude value)and the damage degree of steel pipe specimens,the crack propagation law and crack initiation load value of steel pipe after corrosion damage are obtained.Analyzing the different change characteristics of the relationship curve between the displacement of the loading point and the acoustic parameters,the general location of the steel pipe damage and the exact value p of the crack initiation load are detected.The test results provide a basis for further study on the damage mechanism of steel tube specimens.