本文選題：巖石破碎 + 動靜載荷　； 參考：《湖南科技大學(xué)》2017年碩士論文

【摘要】：巖石破碎聲發(fā)射和電磁輻射現(xiàn)象是巖石受載作用獲得能量后,將存儲的能量以聲能和電磁能釋放的兩種物理效應(yīng)。針對這些物理效應(yīng)的研究,目前主要集中在對巖石受載產(chǎn)生的聲發(fā)射或電磁輻射單一特性方面上,而對巖石在受不同載荷情況下兩者的同步研究的較少。為探討受不同載荷時脆性巖石破碎表現(xiàn)出來的聲電特性,本文分別開展單軸靜載下壓頭、刀具作用下以及動靜載荷作用下不同脆性巖石破碎聲發(fā)射與電磁輻射試驗,根據(jù)采集的聲電信號對巖石破碎全過程的聲發(fā)射、電磁輻射特性進行探討,然后分析總結(jié)脆性巖石受不同載荷作用下破碎特點以及產(chǎn)生的聲發(fā)射、電磁輻射特征參量變化。論文主要內(nèi)容及結(jié)論如下:(1)運用破碎力學(xué)理論分析了靜載作用下刀具侵入力的影響因素及動載作用下巖石應(yīng)力波的獲取過程,探討了巖石受載荷作用下破碎過程的聲發(fā)射產(chǎn)生機制,得出聲發(fā)射率和應(yīng)力強度因子、裂紋長度增量的具體關(guān)系;分析了破碎過程電磁輻射信號特點,探討了電磁輻射幅值與巖石屬性參數(shù)之間的關(guān)系,得到了電磁輻射幅值隨巖石彈性模量增加而增大,巖石受載應(yīng)力越大,電磁輻射幅值反而越小;電磁輻射幅值隨巖石彈模的增大趨勢要比隨巖石泊松比的增大趨勢大得多。(2)選用典型脆性花崗巖為研究對象對其開展了壓頭與刀具作用下的聲發(fā)射、電磁輻射試驗。結(jié)果表明:壓頭與刀具作用下巖石受載破壞產(chǎn)生聲發(fā)射、電磁輻射信號變化規(guī)律具有差異性,當(dāng)巖石發(fā)生破壞前,平端壓頭加載作用下巖石聲發(fā)射振鈴計數(shù)率和能量率隨載荷增加逐漸增大,電磁輻射信號隨載荷增加逐漸增大,而刀具靜力侵入巖石聲發(fā)射振鈴計數(shù)率和能量率呈躍進式變化,電磁輻射信號會出現(xiàn)突增現(xiàn)象。(3)對比分析壓頭與刀具作用下巖石受載過程聲發(fā)射和電磁輻射特征結(jié)果可知:巖石受載破壞過程中聲發(fā)射和電磁輻射均與載荷存在正相關(guān)耦合關(guān)系,二者具有較好的相關(guān)性,能很好反映巖石的變形破壞過程,但巖石產(chǎn)生的電磁輻射信號比聲發(fā)射信號要豐富得多、出現(xiàn)也早,電磁輻射比聲發(fā)射有著更廣泛的產(chǎn)生機制。(4)在靜載作用下,在加載初期巖石有少量的聲發(fā)射、電磁輻射信號出現(xiàn),不同巖樣破壞過程中都伴隨著聲發(fā)射、電磁輻射信號的產(chǎn)生,但強度高的巖樣,在破壞過程中接受到的聲發(fā)射、電磁輻射信號峰值大,不同試樣間大能量的事件往往對應(yīng)少的振鈴計數(shù),多的振鈴計數(shù)往往對應(yīng)能量小的事件,試驗過程中接收的電磁輻射脈沖數(shù)信號和時間的變化規(guī)律具有良好的對應(yīng)關(guān)系。(5)在動載作用下,對比同一種試樣聲電信號發(fā)現(xiàn),巖石應(yīng)力的峰值和聲發(fā)射信號峰值大概處于同一時間段,但是電磁輻射信號的峰值比應(yīng)力峰值、聲發(fā)射信號峰值的時間都要早些。(6)對比分析動靜載荷巖石破碎聲電試驗數(shù)據(jù)結(jié)果,表明聲電信號的每一次較大的跳躍波動代表巖石的一次破碎,試驗過程中聲發(fā)射、電磁輻射信號都能較好的反映試樣的受力狀態(tài)和變形破壞程度,和試樣的破碎形態(tài)是相互對應(yīng)的,可以通過電磁輻射和聲發(fā)射技術(shù)監(jiān)測巖石的受力及破壞情況,在工程實踐中能夠起到一定的預(yù)測預(yù)警作用。
[Abstract]:The acoustic emission and electromagnetic radiation of rock breaking are the two physical effects that the stored energy is released by sound energy and electromagnetic energy after the rock is loaded, and the research on these physical effects is mainly focused on the single characteristic of acoustic emission or electromagnetic radiation produced by rock loading, and the rock is loaded with different loads. In order to investigate the acoustic and electrical characteristics of brittle rocks under different loads, the acoustic emission and electromagnetic radiation of different brittle rocks under the action of the tool and the dynamic and static loads are tested in this paper. The characteristics of the acoustic emission and electromagnetic radiation of the process are discussed, and then the characteristics of the brittle rocks under different loads, the acoustic emission and the characteristic parameters of the electromagnetic radiation are analyzed. The main contents and conclusions of this paper are as follows: (1) the influence factors and the dynamic load of the tool invasion force under the static load are analyzed by the theory of fracture mechanics. Using the process of obtaining the rock stress wave, the mechanism of acoustic emission produced by the rock under loading is discussed, and the specific relation between the acoustic emission rate and the stress intensity factor and the crack length increment is obtained. The characteristics of the electromagnetic radiation signal in the crushing process are analyzed, and the relationship between the electromagnetic radiation amplitude and the rock property parameters is discussed. The amplitude of electromagnetic radiation increases with the increase of the elastic modulus of rock. The larger the load stress is, the smaller the amplitude of the electromagnetic radiation, the increasing trend of the electromagnetic radiation amplitude with the rock mass ratio is much larger than that of the rock Poisson's ratio. (2) the typical brittle granite is selected as the research object under the action of the pressure head and the cutting tool. Acoustic emission and electromagnetic radiation test. The results show that the load of rock under the action of the pressure head and the tool produces acoustic emission, and the change law of electromagnetic radiation signal is different. When the rock is damaged, the rate and the energy rate of the sound emission ringing increase with the load, and the electromagnetic radiation signal increases with the load. Adding gradually, the counting rate and the energy rate of the acoustic emission ringing of the rock cutters show a leap forward change, and the electromagnetic radiation signal will appear abrupt increase. (3) the characteristics of acoustic emission and electromagnetic radiation of rock loading process under the action of pressure head and cutting tools are compared and analyzed. There is a positive correlation coupling relationship between the two ones, which has good correlation and can well reflect the deformation and failure process of rock, but the electromagnetic radiation signals produced by the rock are much richer than acoustic emission signals, and the electromagnetic radiation has a more extensive generation mechanism than acoustic emission. (4) under the static loading, there are a small amount of rock at the initial stage of loading. Acoustic emission and electromagnetic radiation signal occur. In the process of damage of different rock samples, acoustic emission and electromagnetic radiation are produced, but the high intensity samples are received by acoustic emission during the failure process, the peak of electromagnetic radiation signal is large. The events of large energy in different samples often correspond to few ringing counts, and the number of ringing counts often corresponds to the energy. There is a good correspondence relationship between the number of electromagnetic radiation pulses received in the test process and the changing law of time. (5) under the action of dynamic load, the peak of rock stress and the peak of acoustic emission signal are probably in the same period, but the peak value of the electromagnetic radiation signal is compared to the stress peak under the action of dynamic load. Value, the time of the peak of acoustic emission signal should be earlier. (6) comparing and analyzing the results of the acoustic and electroacoustic test data of rock breaking and static load, it shows that each big jump wave of the acoustic signal represents the one break of the rock. The acoustic emission and electromagnetic radiation signal in the test process can better reflect the stress state and the degree of deformation and damage of the specimen. The fracture morphology of the specimen is corresponding to each other. It can monitor the stress and damage of the rock by electromagnetic radiation and acoustic emission technology, and can play a certain predictive and early warning role in the engineering practice.

【學(xué)位授予單位】：湖南科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TD315

【參考文獻】

相關(guān)期刊論文 前10條

1 郝兵元;黃輝;馮子軍;王凱;馮國瑞;康立勛;;單軸應(yīng)力狀態(tài)下石灰?guī)r體靜態(tài)破碎裂紋演化規(guī)律及應(yīng)用[J];煤炭學(xué)報;2014年12期

2 陶鑫;謝子令;郝圣旺;周華飛;;鋼纖維增強粉煤灰地質(zhì)聚合物單軸受壓過程的聲發(fā)射特性[J];復(fù)合材料學(xué)報;2014年06期

3 俞縉;李宏;陳旭;蔡燕燕;穆康;張亞洲;武娜;;砂巖卸圍壓變形過程中滲透特性與聲發(fā)射試驗研究[J];巖石力學(xué)與工程學(xué)報;2014年01期

4 楊永杰;王德超;郭明福;李博;;基于三軸壓縮聲發(fā)射試驗的巖石損傷特征研究[J];巖石力學(xué)與工程學(xué)報;2014年01期

5 王曉南;陸菜平;薛俊華;余國鋒;羅勇;劉輝;張軍偉;;煤巖組合體沖擊破壞的聲發(fā)射及微震效應(yīng)規(guī)律試驗研究[J];巖土力學(xué);2013年09期

6 邱黎明;王恩元;;含孔洞混凝土單軸壓縮實驗的聲電信號特征[J];煤礦安全;2013年06期

7 金佩劍;王恩元;宋大釗;黃寧;王嗣衡;;單軸循環(huán)加載煤巖電磁輻射規(guī)律實驗研究[J];煤礦安全;2013年05期

8 許江;劉義鑫;吳慧;高健;陸麗豐;;剪切荷載條件下巖石細觀破壞及聲發(fā)射特性研究[J];礦業(yè)安全與環(huán)保;2013年01期

9 孫強;劉曉斐;薛雷;;煤系巖石脆性破壞臨界電磁輻射信息分析[J];應(yīng)用基礎(chǔ)與工程科學(xué)學(xué)報;2012年06期

10 吳賢振;劉祥鑫;梁正召;游勛;余敏;;不同巖石破裂全過程的聲發(fā)射序列分形特征試驗研究[J];巖土力學(xué);2012年12期

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