本文選題：非線性超聲 + 信號(hào)調(diào)理��； 參考：《電子科技大學(xué)》2017年碩士論文

【摘要】：在當(dāng)今的工業(yè)生產(chǎn)中,金屬構(gòu)件在各類生產(chǎn)設(shè)備中被廣泛地使用。而伴隨著金屬構(gòu)件的制造、加工以及使用,會(huì)不可避免地在其表面或者內(nèi)部形成微裂紋。同時(shí),在長(zhǎng)期載荷、溫度變化和腐蝕介質(zhì)的影響下,金屬構(gòu)件的微裂紋會(huì)增大,導(dǎo)致金屬構(gòu)件的斷裂,給生產(chǎn)造成巨大的危害和損失。因此,檢測(cè)金屬構(gòu)件的微裂紋已迫在眉睫。傳統(tǒng)的超聲波檢測(cè)方法是利用聲波的反射、散射等線性特征進(jìn)行檢測(cè),故受限于其原理,對(duì)金屬微裂紋的檢測(cè)不敏感。而根據(jù)最新的材料力學(xué)和聲學(xué)研究表明,材料內(nèi)部性能變化(如應(yīng)力、微裂紋等)與材料的超聲非線性效應(yīng)有著密切的關(guān)聯(lián)。因此,非線性超聲檢測(cè)在材料的無(wú)損檢測(cè)工作中得到了廣泛的關(guān)注。但是對(duì)于非線性超聲檢測(cè)系統(tǒng)的開發(fā)還不盡完善,因此本文設(shè)計(jì)了一套完整的非線性超聲檢測(cè)系統(tǒng),具體包括以下內(nèi)容:1.首先是對(duì)非線性超聲理論進(jìn)行了相關(guān)研究,從非線性超聲響應(yīng)信號(hào)的分析出發(fā),闡述了在非線性超聲中高次諧波產(chǎn)生的原理。然后從理想情況下的一維非線性波動(dòng)方程和連續(xù)性方程出發(fā),推導(dǎo)出二階相對(duì)非線性系數(shù),并作為非線性超聲檢測(cè)的判斷依據(jù)。2.接著介紹了現(xiàn)階段非線性超聲檢測(cè)常用的檢測(cè)方法,根據(jù)非線性超聲的相關(guān)知識(shí)和自身?xiàng)l件選取有限振幅法作為本文金屬微裂紋的非線性超聲檢測(cè)方法,并設(shè)計(jì)一套完整的非線性超聲檢測(cè)方案。3.設(shè)計(jì)合理的信號(hào)調(diào)理電路,對(duì)超聲換能器接收端接收到的信號(hào)進(jìn)行預(yù)處理。同時(shí)設(shè)計(jì)一套基于FPGA的非線性超聲信號(hào)采集系統(tǒng),包括其硬件電路設(shè)計(jì)和功能實(shí)現(xiàn)。4.利用上述設(shè)計(jì)的檢測(cè)方案進(jìn)行實(shí)驗(yàn)平臺(tái)搭建,對(duì)鋁制試件進(jìn)行非線性超聲實(shí)驗(yàn)檢測(cè),并對(duì)結(jié)果進(jìn)行處理和分析,從而驗(yàn)證該非線性超聲檢測(cè)系統(tǒng)的實(shí)用性。
[Abstract]:In today's industrial production, metal components are widely used in all kinds of production equipment. With the manufacture, processing and use of metal components, microcracks will inevitably form on the surface or inside of metal components. At the same time, under the influence of long-term load, temperature change and corrosion medium, the micro-crack of metal member will increase, which will lead to the fracture of metal member and cause great harm and loss to production. Therefore, it is urgent to detect microcracks in metal components. The traditional ultrasonic detection method is based on the linear characteristics such as reflection and scattering of sound waves, so it is limited by its principle and is not sensitive to the detection of metal microcracks. According to the latest material mechanics and acoustics studies, it is shown that the change of internal properties (such as stress, microcracks, etc.) is closely related to the ultrasonic nonlinear effect of materials. Therefore, nonlinear ultrasonic testing has been widely concerned in the nondestructive testing of materials. However, the development of nonlinear ultrasonic detection system is not perfect, so this paper designs a complete nonlinear ultrasonic detection system, including the following contents: 1. Firstly, the theory of nonlinear ultrasound is studied. Based on the analysis of nonlinear ultrasonic response signal, the principle of high-order harmonic generation in nonlinear ultrasound is expounded. Then the second order relative nonlinear coefficient is derived from the one-dimensional nonlinear wave equation and continuity equation under ideal condition, which is used as the judgment basis of nonlinear ultrasonic detection. Then it introduces the commonly used detection methods of nonlinear ultrasonic detection at present. According to the relevant knowledge of nonlinear ultrasound and its own conditions, the finite amplitude method is selected as the nonlinear ultrasonic detection method for metal microcracks in this paper. And designed a complete set of nonlinear ultrasonic detection scheme. 3. A reasonable signal conditioning circuit is designed to preprocess the signal received at the receiving end of the ultrasonic transducer. At the same time, a nonlinear ultrasonic signal acquisition system based on FPGA is designed, including its hardware circuit design and function realization. The experimental platform is built with the above designed testing scheme, and the nonlinear ultrasonic testing of aluminum specimen is carried out, and the results are processed and analyzed to verify the practicability of the nonlinear ultrasonic testing system.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG115.285

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張洪明;班釗;李雪;徐先春;;基于AD8421的稱重傳感器信號(hào)調(diào)理設(shè)計(jì)[J];電子制作;2015年13期

2 陸銘慧;王旭;;非線性超聲檢測(cè)信號(hào)提取的電路設(shè)計(jì)及測(cè)試[J];失效分析與預(yù)防;2014年01期

3 李新明;段家寶;李常勝;;關(guān)于超聲波無(wú)損檢測(cè)技術(shù)的應(yīng)用研究[J];中國(guó)高新技術(shù)企業(yè);2014年05期

4 稅國(guó)雙;黃蓬;;基于應(yīng)力波因子的金屬材料表面塑性損傷檢測(cè)[J];材料工程;2013年11期

5 白佳俊;孟祥勇;張德平;馮起;袁乃昌;;基于W5300和FPGA的實(shí)時(shí)數(shù)據(jù)采集系統(tǒng)設(shè)計(jì)[J];電子技術(shù)應(yīng)用;2013年04期

6 陸銘慧;徐肖霞;;非線性超聲檢測(cè)方法及應(yīng)用[J];無(wú)損檢測(cè);2012年07期

7 金磊;夏才初;;理論流變力學(xué)模型中蠕變損傷的研究方法與問(wèn)題[J];巖石力學(xué)與工程學(xué)報(bào);2012年S1期

8 張勇;甄國(guó)涌;王麗莉;任勇峰;;基于W5300的以太網(wǎng)數(shù)據(jù)傳輸硬件設(shè)計(jì)及優(yōu)化[J];化工自動(dòng)化及儀表;2011年08期

9 周正干;劉斯明;;非線性無(wú)損檢測(cè)技術(shù)的研究、應(yīng)用和發(fā)展[J];機(jī)械工程學(xué)報(bào);2011年08期

10 陳振華;史耀武;趙海燕;;超聲檢測(cè)換能器高次諧波的提取及應(yīng)用[J];儀器儀表學(xué)報(bào);2010年07期

相關(guān)博士學(xué)位論文 前1條

1 胡海峰;板狀金屬結(jié)構(gòu)健康監(jiān)測(cè)的非線性超聲理論與關(guān)鍵技術(shù)研究[D];國(guó)防科學(xué)技術(shù)大學(xué);2011年

相關(guān)碩士學(xué)位論文 前1條

1 徐正安;基于FPGA的線陣CCD測(cè)量系統(tǒng)的設(shè)計(jì)[D];重慶大學(xué);2012年

，

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