Welded Joints Fatigue Cumulative Damage Behavior Based on Magnetic Memory Mechanism
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摘要: 通过20号钢焊接平板试件的拉-拉疲劳试验，研究了在单周期和多周期循环载荷下焊缝疲劳累积损伤的磁记忆信号特征。结果表明，由于试件内部初始状态下各处应力分布不均匀，焊缝原始磁信号表现为起伏较大;随着循环周次的增加，试件内部应力集中重新分布，信号趋于稳定;在周期累积循环试验中，磁记忆信号随着循环周次的增加出现螺旋上升的趋势，呈现出磁弹性效应变化特征;通过建立磁记忆信号与损伤度函数的模型，可根据磁记忆信号的变化准确判断裂纹扩展趋势，用于焊缝剩余寿命的预测。Abstract: In order to get metal magnetic memory(MMM) signal characteristics under single cycle tension loading and multi-cyclic fatigue loading, 20 steel welded plate specimens were tested by experiments. In single cycle tension experiments, the loading is increased from 20 kN to 60kN at 10kN interval space. In multi-cyclic tension fatigue experiments，the static loading is 35kN and the stress ratio is 1/6. The results showed that MMM signals had fluctuations throughout the specimens under the initial state because of the residual stress distributed uniformly on welded joints. With the increment of tension loading, internal stress was redistributed again and MMM signal tended to be stable. In the cycle cumulative experiments, MMM signals show a loop-arising trend along with the increase of cycle numbers, reflecting the magnetic elastic variation effect. By establishing the relational model between the damage degree and the magnetic memory signal, the fatigue residual life of welded joints can be forecasted.
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[1] Doubov A A. Diagnostics of metal and equipment by means of metal magnetic memory［C］. Proceeding of Seventh Conference on NDT and International Research Symposium. Shantou, China,1999:181-187. [2] Doubov A A. Technical diagnostics of equipment and constructions with residual life assessment using the method of metal magnetic memory［C］. 17th World Conference on Nondestructive testing, Shanghai, China,2008:25-28. [3] 林俊明，林春景，林发柄.基于磁记忆效应的一种无损检测新技术［J］.无损检测,2000,22(7):297-299. [4] 李国栋.当代磁学［M］.合肥：中国科学技术大学出版社,1999. [5] 邸新杰.焊接裂纹的金属磁记忆信号定量化特征研究［D］.天津：天津大学,2007. [6] 邢海燕，陈鑫彧，黄保富，等.拉压载荷下焊缝的磁记忆表征及热处理评价［J］.大庆石油学院学报,2011,35(1):100-104. [7] 邸新杰，李午申，白世武.焊接裂纹金属磁记忆信号的特征提取与应用［J］ .焊接学报,2006,27(2):19-22. [8] 邢海燕，樊久铭，王日新，等.早期损伤临界应力状态磁记忆检测技术［J］.哈尔滨工业大学学报,2009,41(5):26-30. [9] 刘红光，张卫民，王朝霞.基于磁记忆法的焊接缺陷检测技术研究［J］.北京理工大学学报,2007,27(9):811. [10] 王文江，戴光.疲劳断裂试件磁记忆检测结果及分析［J］.大庆石油学院学报,2005,29(4):83-85.
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