首页|考虑残余应力影响的典型钢结构对接焊缝缺陷定位研究

考虑残余应力影响的典型钢结构对接焊缝缺陷定位研究

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对接焊缝为典型的钢结构焊缝形式,其位置处的裂纹和气孔型缺陷的准确检测对于钢结构维护有着重要的意义,使用磁记忆检测技术对焊缝裂纹和气孔型缺陷进行定位时,传统的零点极值理论由于焊接残余应力的影响,难以区分残余应力、焊接裂纹和气孔型缺陷所产生的磁信号,从而在实际检测中造成缺陷定位的误判和漏判,因此,从焊接裂纹和气孔型缺陷和残余应力所在区域磁信号产生机理的不同入手,开展考虑残余应力影响下的焊接裂纹和气孔型缺陷定位检测研究.首先对焊接残余应力与裂纹和气孔型缺陷产生磁信号的机理进行分析,提出采用三维磁模量梯度极值判定方式来区分残余应力与裂纹和气孔型缺陷产生的磁信号;其次再进行焊接缺陷有限元COMSOL模拟,将所得磁信号代入梯度极值特征公式中进行表征判断;最后为了验证模拟表征判断的准确性,人工制作焊接钢板,提取三维磁信号进行分析.研究结果表明,理论分析、数值模拟与试验结果相互吻合,三维磁模量梯度极值能定位焊接缺陷并定量表征缺陷的长度,且裂纹和气孔型的三维磁模量梯度值远远高于无缺陷残余应力区域的梯度值.
Defect Locating of Typical Steel Structure Butt Weld Considering the Influence of Residual Stress
Butt weld is a typical weld form in steel structures,and the accurate detection of cracks and porosity defects at their locations are of great significance for the maintenance of steel structure.In the case of using magnetic memory testing technology to locate weld cracks and porosity defects,the traditional zero extreme value theory will be affected by welding residual stress,and it is difficult to distinguish residual stress and magnetic signals generated by welding cracks and porosity defects.Therefore,starting from the difference in the mechanism of magnetic signal generation in the area where welding cracks and porosity defects and residual stress are located,this paper presents a research on the location detection of welding cracks and porosity defects under the influence of residual stress.Firstly,the mechanism of magnetic signals generated by welding residual stress and cracks and porosity defects is analyzed,and the 3D magnetic modulus gradient extreme value judgment method is proposed to distinguish the magnetic signals generated by welding residual stress and cracks and porosity defects.Secondly,a finite element COMSOL simulation of welding defects is carried out,and the magnetic signals obtained are brought into the gradient extreme value characteristic formula for assessment.Finally,in order to verify the accuracy of the simulation characterization assessment,the welded steel plate is artificially made,and the three-dimensional magnetic signal is extracted for analysis.The research results show that the theoretical analysis,numerical simulation and experimental results are consistent.The extreme value of three-dimensional magnetic modulus gradient can locate welding defects and quantitatively characterize the length of defects,and the three-dimensional magnetic modulus gradient value of crack and pore type is far higher than the gradient value of defect free residual stress area.

weld crackporosity defectmetal magnetic memory testingCOMSOL simulationthree-dimensional magnetic modulus gradient

陈悦、潘学豪、邓淋方

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重庆交通大学山区桥梁及隧道工程国家重点实验室,重庆 400074

重庆交通大学土木工程学院,重庆 400074

焊缝裂纹 气孔型缺陷 磁记忆检测 COMSOL模拟 三维磁模量梯度

重庆市自然科学基金

cstc2019jcyj-msxmX0556

2024

建筑钢结构进展
同济大学

建筑钢结构进展

CSTPCD北大核心
影响因子:0.806
ISSN:1671-9379
年,卷(期):2024.26(4)
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