多周期动态循环应力下的J-A-N力磁耦合机理模型
J-A-N Force Magnetic Coupling Mechanism Model under Multi Cycle Dynamic Cyclic Stresses
邢海燕 1刘伟男 1陈龙 1徐成 1弋鸣 1颜俊杰1
作者信息
- 1. 东北石油大学机械科学与工程学院,大庆,163318
- 折叠
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,am主要影响应力饱和磁化大小;am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.
Abstract
At present,force magnetic coupling J-A model did not consider the influences of do-main 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.Further-more,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 amplitudes σa and mean stressσm.With the same cycle times,the σa mainly affects the stress magnetization rate,while the static mean stress σm mainly affects the stress saturation magnetization size.When the same σm is constant,with the increase of σa,the speed of reaching stress saturation state increases.When the same σa is constant,the stress saturation magnetization decreases with the increase of σm.To verify the effective-ness 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.
关键词
J-A模型/力磁耦合/磁记忆检测/早期疲劳损伤Key words
Jiles-Atherton(J-A)model/magneto-mechanical effect/magnetic memory detection/early fatigue damage引用本文复制引用
基金项目
国家自然科学基金(11272084)
黑龙江省自然科学基金(LH2019A004)
出版年
2024
国家科技期刊平台
NSTL
万方数据