北京科技大学学报
北京科技大學學報
북경과기대학학보
JOURNAL OF UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING
2013年
12期
1615-1621
,共7页
材料疲劳%拉伸试验%循环载荷%磁记忆%疲劳损伤
材料疲勞%拉伸試驗%循環載荷%磁記憶%疲勞損傷
재료피로%랍신시험%순배재하%자기억%피로손상
fatigue of materials%tensile testing%cyclic loads%magnetic memory%fatigue damage
设计拉伸疲劳试验,研究了疲劳载荷下磁信号暂时到达的稳定状态的特点以及疲劳过程中磁信号的分布、变化情况,并结合改进的 J-A 理论进行分析和讨论。结果显示:磁信号暂时到达的稳定状态在一个循环周期内沿环线变化,并且环线随循环载荷类型不同而变化,说明用改进的 J-A 理论描述磁记忆现象合理;疲劳过程中磁信号分三个阶段变化,这个特征由改进的J-A模型中描述磁畴壁运动所受阻碍的参数(ξ″)随疲劳损伤发展的变化规律解释;磁信号在缺陷附近呈“⌒”形的分布,这个特征由缺陷附近ξ″的分布规律解释。
設計拉伸疲勞試驗,研究瞭疲勞載荷下磁信號暫時到達的穩定狀態的特點以及疲勞過程中磁信號的分佈、變化情況,併結閤改進的 J-A 理論進行分析和討論。結果顯示:磁信號暫時到達的穩定狀態在一箇循環週期內沿環線變化,併且環線隨循環載荷類型不同而變化,說明用改進的 J-A 理論描述磁記憶現象閤理;疲勞過程中磁信號分三箇階段變化,這箇特徵由改進的J-A模型中描述磁疇壁運動所受阻礙的參數(ξ″)隨疲勞損傷髮展的變化規律解釋;磁信號在缺陷附近呈“⌒”形的分佈,這箇特徵由缺陷附近ξ″的分佈規律解釋。
설계랍신피로시험,연구료피로재하하자신호잠시도체적은정상태적특점이급피로과정중자신호적분포、변화정황,병결합개진적 J-A 이론진행분석화토론。결과현시:자신호잠시도체적은정상태재일개순배주기내연배선변화,병차배선수순배재하류형불동이변화,설명용개진적 J-A 이론묘술자기억현상합리;피로과정중자신호분삼개계단변화,저개특정유개진적J-A모형중묘술자주벽운동소수조애적삼수(ξ″)수피로손상발전적변화규률해석;자신호재결함부근정“⌒”형적분포,저개특정유결함부근ξ″적분포규률해석。
Tensile fatigue experiments were performed to study the characteristic of temporary stable magnetiza-tion states under fatigue loading, as well as the distribution and variation of magnetic memory signal in the process of fatigue. Experimental results were analyzed and discussed using the modified J-A model. It is found that the temporary stable magnetization state of magnetic signal varies along a loop in a stress cycle and the loop changes when the fatigue load type changes, which indicates that it is reasonable using the modified J-A model to describe the magnetic memory phenomenon of metal. The change of magnetic signal is divided into three stages in the process of fatigue, which is explained according to the change law of parameter ξ″(the parameter expresses the obstruction to magnetic domain wall motion) using the modified J-A model. The magnetic signal distributing in a‘⌒’ shape around a defect is explained according to the distribution law ofξ″around the defect.