基于磁记忆的钢梁弯曲应力表征技术研究.pdf

第 47 卷第 4 期 西安建筑科技大学学报（自然科学版） Vol.47 No.4 2015 年 8 月 J. Xian Univ. of Arch. Tech. (Natural Science Edition) Aug. 2015 DOI ：10.15986/j.1006-7930.2015.04.001 基于磁记忆的钢梁弯曲应力表征技术研究  苏三庆，曾发荣，王 威，易术春 （西安建筑科技大学土木工程学院，陕西 西安 710055 ） 摘要：金属磁记忆检测技术是一种新型的无损检测技术．通过对 Q235B 工字钢梁试件进行四点受弯试验，分析其表面的磁 记忆信号，发现：试件翼缘的磁记忆信号曲线形状与对应的弯矩图相似，均在纯弯段相等，在两端弯剪段近似呈线性分布； 在剪应力突变处，磁记忆信号梯度 K 值“过零点”且出现正负突变现象；试件腹板的磁记忆信号在荷载作用点处呈峰值， 磁记忆信号梯度出现峰-峰值 Kmax 且过零点；不同的变形阶段，磁记忆信号与应力表现出相似的变化趋势． 关键词 ：建筑钢结构；磁记忆；受弯钢梁；应力集中 中图分类号：TU391 文献标志码：A 文章编号：1006-7930(2015)04-0463-6 Research on the bending stress characterization technique of steel beam based on metal magnetic memory SU Sanqing, ZENG Farong, WANG Wei, YI Shuchun (School of Civil Engineering, Xian Univ. of Arch. Tech., Xian 710055, China) Abstract: Metal Magnetic Memory Technology is a new type of non-destructive testing techniques. By the Q235B beam specimens of four-point flexural testing, the surface magnetic memory signals of the beam was analyzed, with some result obtained therein. The bending moment diagram and the flange of magnetic memory signal curve shape is similar, both in pure bending segment is equal, and perform linear distribution approximation at the ends of the bending shear segment. In shear stress mutation, the magnetic gradient memory signal K value pass zero point, and have the mutation phenomenon from positive to negative value. Magnetic memory signal of the web of steel beam has a peak value in loading point, and the gradient of magnetic memory signal have a peak to peak value of Kmax and pass zero point. Magnetic memory signal and stress development showed a similar trend at different deformation stages. Key words: Bu