本文選題：高頻渦流加載 + 閉合裂紋��； 參考：《河北工業(yè)大學(xué)》2015年碩士論文

【摘要】：高頻渦流加載下,處于靜磁場(chǎng)中的金屬板將在洛倫茲力作用下,產(chǎn)生應(yīng)力波,當(dāng)金屬板中存在不連續(xù)界面時(shí),渦流在此集中,進(jìn)而洛倫茲力的作用將顯著增強(qiáng),并將影響金屬板中超聲波的傳播過程。本文詳細(xì)研究了高頻渦流加載下金屬板電磁場(chǎng)、力場(chǎng)和位移場(chǎng)的多場(chǎng)耦合理論,給出了基于洛倫茲力機(jī)理的高頻渦流加載耦合方程。在此基礎(chǔ)上,研究了高頻渦流加載下金屬微裂紋界面的波動(dòng)機(jī)理,建立了金屬板多物理場(chǎng)三維有限元分析模型,求解了含微裂紋鋁板的渦流、磁場(chǎng)及洛倫茲力分布,模擬了微裂紋對(duì)鋁板中超聲波傳播的影響�；诜蔷�性彈簧原理,分別建立了金屬閉合裂紋的數(shù)學(xué)模型和有限元分析模型,仿真了閉合裂紋的波動(dòng)過程對(duì)金屬板中超聲波傳播特性的影響。建立了含閉合裂紋金屬結(jié)構(gòu)中電磁超聲的二維有限元仿真模型,模擬了電磁超聲表面波傳播過程中振動(dòng)質(zhì)點(diǎn)的位移場(chǎng)及其幅頻特性,通過分析二次諧波分量研究了電磁超聲表面波在含閉合裂紋金屬鋁板中的非線性傳播特性。
[Abstract]:Under the loading of high frequency eddy current, the metal plate in the static magnetic field will produce stress wave under the action of Lorentz force. When there is a discontinuous interface in the plate, the eddy current will be concentrated here, and the effect of Lorentz force will be greatly enhanced. The propagation of ultrasonic wave in metal plate will be affected. In this paper, the coupling theory of electromagnetic field, force field and displacement field of metal plate under high frequency eddy current loading is studied in detail, and the coupling equation of high frequency eddy current loading based on Lorentz force mechanism is given. On this basis, the wave mechanism of metal microcrack interface under high frequency eddy current loading is studied, and the three-dimensional finite element analysis model of multi-physical field of metal plate is established, and the eddy current, magnetic field and Lorentz force distribution of aluminum plate with micro-cracks are solved. The effect of microcracks on ultrasonic propagation in aluminum plate was simulated. Based on the principle of nonlinear spring, the mathematical model and finite element analysis model of metal closed crack are established, and the influence of the wave process of closed crack on the ultrasonic propagation characteristics of metal plate is simulated. A two-dimensional finite element simulation model of electromagnetic ultrasound in metal structures with closed cracks is established. The displacement field and amplitude and frequency characteristics of vibrating particles in the process of surface wave propagation are simulated. The nonlinear propagation characteristics of electromagnetic ultrasonic surface waves in aluminum plates with closed cracks are studied by analyzing the second harmonic component.
【學(xué)位授予單位】：河北工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TG115.28
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本文編號(hào)：1776944