發(fā)布時間：2018-12-15 02:09

【摘要】：鐵磁性材料在機械特性方面具有良好的適應(yīng)性,因此在鐵路、運輸、建筑等方面被作為關(guān)鍵材料,得到廣泛的應(yīng)用。鐵磁性材料在服役過程中,受力復(fù)雜,易形成局部應(yīng)力和應(yīng)力集中,最終造成局部塑性變形,產(chǎn)生缺陷,長期使用會導(dǎo)致疲勞損傷。另外,溫度變化導(dǎo)致的熱脹冷縮的溫度應(yīng)力和加工工藝導(dǎo)致的殘余應(yīng)力分布會在材料內(nèi)部積累。本文選擇巴克豪森噪聲方法進(jìn)行這部分應(yīng)力的檢測。為解決常規(guī)巴克豪森噪聲信號特征值多次采集的波動性,尋找巴克豪森噪聲與材料磁特性的數(shù)學(xué)關(guān)系,本文從巴克豪森信號產(chǎn)生的原理出發(fā),分析了巴克豪森噪聲信號與磁滯回線的關(guān)系,從而提出對巴克豪森噪聲信號包絡(luò)進(jìn)行積分的曲線分析方法,分析了該積分曲線與磁滯回線的關(guān)系,并從積分曲線上提取出新的與應(yīng)力以及材料磁特性相關(guān)的特征值。為完成鐵磁性材料內(nèi)部應(yīng)力以及材料磁特性的檢測,本文以嵌入式芯片為基礎(chǔ)設(shè)計了一套巴克豪森應(yīng)力檢測系統(tǒng),并重點介紹了基于ARM內(nèi)核和Android系統(tǒng)為基礎(chǔ)的人機交互軟件的設(shè)計。使用此應(yīng)力檢測系統(tǒng),本文通過四點彎曲加載實驗證明可使用巴克豪森噪聲方法推算磁滯回線,并可使用積分曲線上的新特征值進(jìn)行應(yīng)力檢測。另外,本文在MTS810伺服液壓試驗平臺上進(jìn)行Q235鋼試件的軸向拉伸試驗,分析了包絡(luò)面積、中心高度差等可靠特征值隨外加拉應(yīng)力的變化趨勢,并通過多試件的對比,分析了材料內(nèi)部應(yīng)力的存在對特征值變化曲線的影響,為應(yīng)力標(biāo)定工作提供依據(jù)。
[Abstract]:Ferromagnetic materials have good adaptability in mechanical properties, so they are widely used as key materials in railway, transportation, construction and so on. In the service process of ferromagnetic materials, it is easy to form local stress and stress concentration, resulting in local plastic deformation, defects and fatigue damage caused by long-term use of ferromagnetic materials. In addition, the thermal stress caused by the temperature change and the residual stress distribution caused by the processing process will accumulate in the material. This paper chooses Barkhausen noise method to measure this part of stress. In order to solve the fluctuation of the characteristic value of conventional Barkhausen noise signal and to find out the mathematical relation between Barkhausen noise and the magnetic properties of materials, this paper starts from the principle of Barkhausen signal generation. The relationship between Barkhausen noise signal and hysteresis loop is analyzed, and the curve analysis method for the envelope of Barkhausen noise signal is put forward, and the relationship between the integral curve and hysteresis loop is analyzed. New eigenvalues related to stress and magnetic properties of materials were extracted from the integral curve. In order to detect the internal stress and magnetic properties of ferromagnetic materials, a Barkhausen stress detection system is designed based on embedded chip. The design of human-computer interaction software based on ARM kernel and Android system is introduced. Using this stress detection system, it is proved that the Barkhausen noise method can be used to calculate the hysteresis loop and the new eigenvalue on the integral curve can be used to detect the stress. In addition, the axial tensile test of Q235 steel specimen is carried out on the MTS810 servo hydraulic test platform. The variation trend of the reliable characteristic values such as envelope area and center height difference with the applied tensile stress is analyzed. The influence of the stress inside the material on the characteristic curve is analyzed, which provides the basis for the work of stress calibration.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TM27

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 劉梅;魯銘;王世苗;徐仕，

本文編號：2379755