本文選題：聲發(fā)射 + Kaiser效應(yīng)　； 參考：《重慶大學(xué)》2015年碩士論文

【摘要】：近年來,由于水利水電、采礦、土建、鐵道橋梁、公路隧道等工程需要,對于巖石聲發(fā)射特性的研究一直以來都是一個非常重要的課題。尤其是針對巖石Kaiser效應(yīng)的研究探討,比如Kaiser點位置判斷方法的研究,巖石Felicity效應(yīng)以及Felicity比的研究,以及巖石記憶效應(yīng)的研究等,都在一定程度上得到了國內(nèi)外學(xué)者們的青睞。影響巖石聲發(fā)射特性以及Kaiser效應(yīng)的因素也越來越成為關(guān)注的話題,諸如尺寸效應(yīng)、溫度效應(yīng)、加載速率、加載方式、均質(zhì)性以及環(huán)境效應(yīng)等。雖然這方面的研究成果已經(jīng)很多,但是巖石聲發(fā)射特性以及Kaiser效應(yīng)影響因素的研究還有待進一步深入。本文主要通過實驗室試驗和數(shù)值模擬的手段分析研究重慶地區(qū)砂巖在三點彎曲試驗條件下的聲發(fā)射特性以及Kaiser效應(yīng)的影響因素。試驗采用TAW 2000D微機控制電液伺服巖石三軸試驗機和DS2數(shù)字聲發(fā)射檢測儀及相應(yīng)配套儀器組成的控制系統(tǒng),可實現(xiàn)電腦控制和實時采集信號,并通過聲發(fā)射處理軟件將電信號轉(zhuǎn)化為試驗數(shù)據(jù)。試驗主要對尺寸效應(yīng)、加載速率、不同材料均質(zhì)性和加載方式進行了研究,觀察和討論了這些試驗條件下的聲發(fā)射特性和是否存在Kaiser效應(yīng),以及巖石記憶效應(yīng)的探討。數(shù)值模擬試驗采用的是RFPA-BASIC軟件對尺寸效應(yīng)、加載速率、不同材料均質(zhì)性和加載方式進行試件破壞過程以及聲發(fā)射特性分析。通過對比分析實驗室試驗和數(shù)值模擬計算結(jié)果,得出以下結(jié)論:1)數(shù)值計算模擬結(jié)果和實際試驗現(xiàn)象吻合程度較高,聲發(fā)射規(guī)律基本上是一致的,Kaier效應(yīng)現(xiàn)象明顯,但是與試驗相比,數(shù)值計算結(jié)果的Felicity比都大于1,記憶效應(yīng)相對滯后。2)砂巖在三點彎曲試驗條件下的聲發(fā)射特性和Kaiser效應(yīng)受到尺寸效應(yīng)的影響,試件尺寸越大,砂巖破壞的時候需要的能量就越大。3)通過花崗巖和砂漿與砂巖的對比,材料的強度越大,累計聲發(fā)射數(shù)量越大,并且聲發(fā)射能量也更大;材料的均質(zhì)程度越小,累計聲發(fā)射數(shù)量以及累計振鈴數(shù)就越大。4)從加載方式上來說,與三點彎曲試驗條件下相比,砂巖在單軸壓縮和劈裂試驗條件下產(chǎn)生的累計聲發(fā)射數(shù)越大,而且釋放的能量也越大。
[Abstract]:In recent years, due to the need of water conservancy and hydropower, mining, civil construction, railway bridge, highway tunnel and so on, the study of acoustic emission characteristics of rock has been a very important subject. Especially for the study of rock Kaiser effect, such as the study of Kaiser point location judgment method, the study of rock Felicity effect and Felicity ratio, and the study of rock memory effect, all of them have been favored by scholars at home and abroad to some extent. The factors affecting the acoustic emission characteristics of rock and the Kaiser effect have become more and more important topics, such as size effect, temperature effect, loading rate, loading mode, homogeneity and environmental effect. Although much research has been done in this field, the characteristics of rock acoustic emission and the influence factors of Kaiser effect need to be further studied. In this paper, the acoustic emission characteristics of sandstone in Chongqing area under three-point bending test and the influencing factors of Kaiser effect are studied by means of laboratory tests and numerical simulation. The control system composed of TAW 2000D microcomputer controlled electro-hydraulic servo rock triaxial testing machine, DS2 digital acoustic emission detector and corresponding instruments can be used to realize computer control and real-time acquisition of signals. The electrical signal is converted into test data by acoustic emission processing software. The size effect, loading rate, homogeneity of different materials and loading mode were studied. The acoustic emission characteristics and the existence of Kaiser effect under these experimental conditions were observed and discussed, as well as the study of rock memory effect. RFPA-BASIC software is used to analyze the size effect, loading rate, material homogeneity and loading mode. By comparing and analyzing the results of laboratory tests and numerical simulation, the following conclusions are drawn: (1) the numerical simulation results are in good agreement with the actual experimental phenomena, and the acoustic emission law is basically consistent with the Kaier effect phenomenon. However, compared with the experimental results, the Felicity ratio of the numerical results is greater than 1, and the memory effect is relatively lagged. 2) the acoustic emission characteristics and the Kaiser effect of sandstone under three-point bending test are affected by the size effect. The larger the specimen size is, the larger the size of the specimen is. The larger the energy required for the destruction of sandstone, the greater the intensity of materials, the greater the amount of cumulative acoustic emissions, and the greater the energy of acoustic emission; the smaller the homogeneity of the materials, the greater the strength of the materials compared with the sandstone. The cumulative number of acoustic emissions and the cumulative number of ringing bells. 4) in terms of loading mode, the cumulative number of acoustic emissions produced by sandstone under uniaxial compression and splitting tests is larger than that under three-point bending test. And the greater the energy released.
【學(xué)位授予單位】：重慶大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU45

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