發(fā)布時間：2018-07-05 14:14

  本文選題：超聲波 + 相控陣�。� 參考：《武漢工程大學(xué)》2014年碩士論文

【摘要】：波在傳播的過程中如果改變了其單一的傳播路徑，就會發(fā)生反射、折射和衍射等現(xiàn)象。超聲波本身是一種高頻率的波，而且指向性很好，所以超聲波檢測的主要原理也是利用這些比其它波表現(xiàn)更加明顯的現(xiàn)象于來檢測評定被檢測的對象是否存在缺陷。目前國內(nèi)已經(jīng)開始初步的應(yīng)用處在國際上最為先進的兩種超聲檢測方法：相控陣與TOFD（衍射時差法）。由于起步緩慢，相關(guān)人才緊缺，設(shè)備也相應(yīng)的落后，為了促進超聲波檢測技術(shù)的發(fā)展，本文對超聲波檢測的兩種先進方法進行了有限元數(shù)值模擬研究�？偟膩碇v，完整的研究分成二個部分，模擬研究是第一步，反推模擬過程是第二步，這里只是作第一部分的研究。主要的目的是證明有限元模擬仿真TOFD法檢測的過程是可行的，可以對檢測進行輔助，彌補了TOFD檢測手段的局限性。 模擬系統(tǒng)是由超聲探頭、楔塊與缺陷試塊三個模型構(gòu)成。超聲波時機械波，符合一般彈性波的傳播規(guī)律，首先確立其在固體中傳播的動態(tài)波動方程，然后再在有缺陷的模型中用TOFD法與相控陣法進行檢測，，最后模擬超聲波的傳播過程，與實驗結(jié)果進行對比分析。結(jié)果表明仿真中的回波幅值精確度不高，而缺陷回波的時間精度很高，這說明了將數(shù)值仿真應(yīng)用在只測量傳播時間就可以對缺陷進行定量的TOFD法中是切實可行的。 TOFD的超聲模型是根據(jù)惠更斯原理建立的，模擬的重點是怎么樣模擬相控陣的波源發(fā)射超聲波，怎么樣施加載荷以及在哪施加載荷。使用TOFD檢測方法得到的人工缺陷的實驗檢測結(jié)果與仿真結(jié)果的相符程度很高。從另外的角度上說，運用仿真手段在實際檢測中對檢測結(jié)果進行輔助分析是切實可行的。傳統(tǒng)的檢測手段模擬的結(jié)果中會波幅值的準(zhǔn)確率不高，但是運用超聲TOFD檢測法只用測量回波時間，彌補了這一缺陷，兩者相輔相成，仿真結(jié)果與實驗結(jié)果的對比說明這種方法是有效的。
[Abstract]:The reflection, refraction and diffraction will occur if the wave changes its single propagation path in the process of propagation. Ultrasonic wave is a kind of high frequency wave, and its directivity is very good. Therefore, the main principle of ultrasonic detection is to use these phenomena, which are more obvious than other waves, to detect and evaluate whether the detected object has defects. At present, two kinds of ultrasonic detection methods, phased array and TOFD (diffraction time difference method), have been applied in our country. In order to promote the development of ultrasonic testing technology, two advanced methods of ultrasonic testing are studied by finite element numerical simulation in order to promote the development of ultrasonic testing technology, because of the slow start, the shortage of related talents and the corresponding backwardness of equipment. In general, the whole study is divided into two parts, the simulation is the first step, the backstepping simulation is the second step, here is only the first part of the study. The main purpose of this paper is to prove that the finite element simulation TOFD method is feasible, which can assist the detection and make up for the limitation of the TOFD detection method. The simulation system consists of three models: ultrasonic probe, wedge and defect test block. The mechanical wave of ultrasonic wave is in accordance with the general law of elastic wave propagation. First, the dynamic wave equation is established, then the TOFD method and phased array method are used to detect the ultrasonic wave in the defective model. Finally, the propagation process of ultrasonic wave is simulated. The results are compared with the experimental results. The results show that the accuracy of echo amplitude in simulation is not high, but the time precision of defect echo is very high. This shows that it is feasible to apply numerical simulation to the TOFD method, which can measure the propagation time only. The ultrasonic model of TOFD is established according to Huygens principle. The emphasis of the simulation is how to simulate the wave source of phased array, how to apply the load and where to apply the load. The experimental results obtained by using TOFD method are in good agreement with the simulation results. From another point of view, it is feasible to use the simulation method to analyze the test results. The accuracy of wave amplitude is not high in the simulation results of traditional detection methods, but the echo time is only measured by using ultrasonic TOFD detection method, which makes up for this defect, and the two methods complement each other. The comparison between the simulation results and the experimental results shows that this method is effective.
【學(xué)位授予單位】：武漢工程大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TB553

【參考文獻】

相關(guān)期刊論文 前10條

1 高鴻海;;大厚度角接焊縫無損檢測[J];東方電機;2006年02期

2 張光義;相控陣雷達的技術(shù)特點及關(guān)鍵技術(shù)[J];電子科技導(dǎo)報;1996年07期

3 孔立峰;李樹學(xué);羅光華;楊景標(biāo);;TOFD檢測技術(shù)的應(yīng)用[J];河北工業(yè)科技;2009年03期

4 鐘文彬;肖永寧;陳世棟;;相控陣超聲波檢測系統(tǒng)及其在工業(yè)無損檢測中的應(yīng)用[J];焊接技術(shù);2006年S1期

5 王傳福;焊縫中橫向裂紋的超聲波檢測[J];無損檢測;2001年03期

6 陳建忠,史耀武;超聲檢測過程的數(shù)值模擬[J];無損檢測;2001年05期

7 曹剛,朱思民;焊縫超聲波檢測回波信號分析[J];無損檢測;2004年10期

8 韓相勇;;長輸管線對接環(huán)焊縫自動相控陣超聲波檢測技術(shù)[J];無損檢測;2006年05期

9 鄭暉;胡斌;林樹青;馬殿忠;;國外TOFD檢測標(biāo)準(zhǔn)分析和比較[J];無損檢測;2007年03期

10 李衍;;ASME法規(guī)對超聲TOFD法的最新規(guī)定介紹第一部分:操作要領(lǐng)[J];無損檢測;2007年04期

本文編號：2100482