金属磁记忆—磁巴克豪森噪声融合检测应力系统的研究及应用

发布时间：2019-02-11 17:00

【摘要】：铁磁构件内部因其焊接、铸造、长期服役会存在内部应力。这些内应力对铁磁构件在使役中的物理性能产生很大的影响。例如焊接过程中产生的焊接应力；爆炸冲击过程中产生的冲击应力；热胀冷缩产生的温度应力。典型的工程问题如无缝线路在使役中纵向温度应力,船用钢板焊接结构应力等等。因此铁磁构件内部应力检测十分必要。论文基于金属磁记忆(MMM)方法和磁巴克豪森噪声(MBN)方法的检测原理,融合两种检测方法的优点,对铁磁材料构件进行在线、无损、快速的应力检测和稳定性分析。主要的研究内容如下：1、利用铁磁构件在交变磁场作用下磁畴壁不可逆位移释放的磁巴克豪森跳跃的平均体积(AVMBJ),以及不可逆磁化率和铁磁构件所受应力之间的关系,推导了磁巴克豪森跳跃平均体积与应力和激励磁场之间的数学关系；分析了应力和磁场作用下的单晶体磁畴壁位移过程；诠释了激励磁场和应力对磁巴克豪森跳跃平均体积的影响。根据铁磁体磁巴克豪森跳跃曲线在受到拉压应力时的饱和速度不相同,引入磁畴壁位移的临界磁场理念,解决了磁巴克豪森跳跃信号随应力变化标定曲线的过饱和标定的问题。2、根据金属磁记忆和磁巴克豪森噪声原理,设计并制作铁磁构件应力检测专用传感器,以及一次信号处理电路：激励电路、放大电路和二次信号处理电路：数据采集电路等。利用高性能的处理器实现丰富的人机交互界面。采用自动控制技术切换金属磁记忆和磁巴克豪森噪声工作系统,实现自动检测。3、研究金属磁记忆和磁巴克豪森噪声检测原理和实现方法,并融合两种方法的优点,针对某些特殊铁磁构件内应力检测区域大、耗时长、实时性的要求,提出了一种金属磁记忆——磁巴克豪森噪声融合的快速应力检测方法,并完成了以下研究：(1)对E36和CCSB级船用钢板焊接应力分布进行分析；对E36级钢板实验船舱爆破冲击前后的焊接应力进行分析；对CCSB级钢板抗冲击实验台焊接应力进行分析。(2)研究无缝线路温度应力的变化规律,根据静力平衡的虚功原理,以及线路的强度和稳定条件,建立了无缝线路稳定性的水坝模型和能量计算公式。利用此公式计算无缝线路当前存储能量,从能量角度说明线路稳定性。(3)基于离散短时傅里叶变换方法,提出一种新的无缝线路整体和局部稳定性检测评估方法,建立了稳定性评估数学计算公式。(4)根据在线检测无缝线路温度应力及现场轨温,建立了无缝线路实际锁定轨温数值计算关系,确定实际锁定轨温检测的在线实施方法。
[Abstract]:Because of welding, casting and long-term service of ferromagnetic components, there will be internal stresses. These internal stresses have a great influence on the physical properties of ferromagnetic components. For example, welding stress in welding process; impact stress in explosion impact process; thermal stress caused by thermal expansion and cold contraction. Typical engineering problems such as longitudinal temperature stress of CWR, stress of welded steel plate structure and so on. Therefore, it is necessary to detect the internal stress of ferromagnetic components. Based on the detection principle of metal magnetic memory (MMM) method and magnetic Barkhausen noise (MBN) method, this paper combines the advantages of the two detection methods to perform on-line, nondestructive, fast stress detection and stability analysis for ferromagnetic materials. The main research contents are as follows: 1. Using the average volume (AVMBJ), of the magnetic Barkhausen jump released by the irreversible displacement of the magnetic domain wall and the relationship between the irreversible susceptibility and the stress of the ferromagnetic member under the action of the alternating magnetic field. The mathematical relationship between the mean volume of magnetic Barkhausen jump and the stress and excitation magnetic field is deduced. The displacement process of single crystal domain wall under the action of stress and magnetic field is analyzed, and the effect of excitation magnetic field and stress on the average volume of magnetic Barkhausen jump is explained. According to the different saturation velocity of magnetic Barkhausen jump curve of ferromagnet under tension and compression stress, the critical magnetic field concept of magnetic domain wall displacement is introduced. The problem of supersaturated calibration of magnetic Barkhausen jump signal with the change of stress is solved. 2. According to the principle of metal magnetic memory and magnetic Barkhausen noise, a special sensor for ferromagnetic component stress detection is designed and fabricated. And the primary signal processing circuit: excitation circuit, amplifier circuit and secondary signal processing circuit: data acquisition circuit. The high performance processor is used to realize rich man-machine interface. Automatic control technology is used to switch metal magnetic memory and magnetic Barkhausen noise working system to realize automatic detection. 3. The principle and realization method of metal magnetic memory and magnetic Barkhausen noise detection are studied, and the advantages of the two methods are combined. In order to meet the requirements of large area, long time consuming and real time of stress detection in some special ferromagnetic components, a fast stress detection method based on magnetic memory, magnetic Barkhausen noise fusion, is proposed. The following studies have been completed: (1) the welding stress distribution of E36 and CCSB grade marine steel plates is analyzed; The welding stress of E36 steel plate experimental cabin before and after blasting impact was analyzed. The welding stress of CCSB steel plate impact test bench is analyzed. (2) the variation law of temperature stress of seamless track is studied, according to the principle of virtual work of static balance, the strength and stability condition of the line, The dam model and energy calculation formula for the stability of CWR are established. Using this formula to calculate the current storage energy of CWR, the stability of the track is explained from the point of view of energy. (3) based on the discrete short time Fourier transform (DSTFT) method, a new method for detecting and evaluating the global and local stability of CWR is proposed. The mathematical formula of stability evaluation is established. (4) based on the on-line measurement of the temperature stress of the seamless track and the field rail temperature, the numerical calculation relationship of the actual lock-in rail temperature of the seamless track is established, and the on-line implementation method of the actual lock-in rail temperature detection is determined.
【学位授予单位】：北京化工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG404;TG115

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