摘要
目前的力磁耦合J-A模型未考虑钉扎场的畴壁厚度与多周期动态循环应力的影响,导致J-A模型的应力磁化数值偏大,不能准确描述早期疲劳损伤。为此,基于畴壁理论和Burgers位错理论,引入畴壁厚度因子,改进J-A模型的钉扎场方程,进一步考虑循环载荷的应力幅、循环周次N等因素,建立了多周期动态循环应力下的J-A-N力磁耦合机理模型。获得了不同动态循环的应力幅值σa与平均应力σm下的磁化规律:相同循环周次下,σa主要影响应力磁化率,σm主要影响应力饱和磁化大小;σm相同时,随着σa的增大,达到应力饱和状态的速度升高;σa相同时,随着σm的增大,应力饱和磁化强度逐渐减小。为验证J-A-N模型有效性,对45钢三点弯曲试件进行了多周期动态循环应力下的磁场信号检测实验,实验结果与模型结果一致。
At present,force magnetic coupling J-A model did not consider the influences of domain wall thickness and multi cycle dynamic cyclic stresses in pinning fields,which resulted in an overestimation of stress magnetization values in the J-A model that could not accurately describe early fatigue damages.Therefore,based on domain wall theory and Burgers dislocation theory,the domain wall thickness factor was introduced to improve the pinning field equation of the J-A model.Furthermore,factors such as stress amplitude and cycle number of cyclic loads were considered,and a J-A-N force magnetic coupling mechanism model under multi cycle dynamic cyclic stress was established.Magnetization laws were obtained under different dynamic cyclic stress amplitudesσa and mean stressσm.With the same cycle times,theσa mainly affects the stress magnetization rate,while the static mean stressσm mainly affects the stress saturation magnetization size.When the sameσm is constant,with the increase ofσa,the speed of reaching stress saturation state increases.When the sameσa is constant,the stress saturation magnetization decreases with the increase ofσm.To verify the effectiveness of the J-A-N model,magnetic field signal detection experiments were conducted on 45 steel three-point bending specimens under multi cycle dynamic cyclic stress,and the experimental results are consistent with the model ones.
作者
邢海燕
刘伟男
陈龙
徐成
弋鸣
颜俊杰
XING Haiyan;LIU Weinan;CHEN Long;XU Cheng;YI Ming;YAN Junjie(School of Mechanical Science and Engineering,Northeast Petroleum University,Daqing,Heilongjiang,163318)
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2024年第9期1542-1547,共6页
China Mechanical Engineering
基金
国家自然科学基金(11272084)
黑龙江省自然科学基金(LH2019A004)。
关键词
J-A模型
力磁耦合
磁记忆检测
早期疲劳损伤
Jiles-Atherton(J-A)model
magneto-mechanical effect
magnetic memory detection
early fatigue damage
