本文選題：紅外輻射溫度 + 受載破壞�。� 參考：《中國礦業(yè)大學》2017年碩士論文

【摘要】：紅外輻射作為一種監(jiān)測煤巖動力災害的地球物理方法,其紅外溫度和紅外熱像具有反映煤巖受壓破壞時間變化和空間演化特征的優(yōu)勢。為了進一步研究裂隙砂巖受載破壞的紅外熱效應及其前兆規(guī)律,本文搭建了裂隙砂巖紅外熱效應實驗系統(tǒng),測試了裂隙不同角度條件下的紅外輻射。根據(jù)測定結果對裂隙砂巖單軸壓縮下紅外輻射溫度不同指標進行分析,并對試樣進行了不同裂隙角度條件下應力場、聲發(fā)射動態(tài)分布和軸向位移場的變化模擬實驗,通過用紅外輻射等值線云圖對試樣失穩(wěn)前關鍵時刻的溫度場演化特征進行了對比分析,研究結果表明:(1)實驗結果表明,試樣受載破壞過程中紅外輻射溫度對破裂具有良好的響應,MIRT(最高紅外輻射溫度)異常信號表現(xiàn)為瞬間的突增、突降,AIRT(平均紅外輻射溫度)表現(xiàn)為整體的降轉升或升轉降。砂巖試樣失穩(wěn)破裂發(fā)生時,最高紅外溫度的增溫幅度隨著角度的增加呈現(xiàn)先升高后降低的趨勢,變化幅度為0.14~1.36~0.11℃,其中轉折點為60°或75°。(2)研究得到了砂巖試樣加載過程中不同區(qū)域紅外溫度變化特征,位于預制裂隙兩端區(qū)域呈現(xiàn)上升狀態(tài),升溫幅度為0.08~0.17℃;位于預制裂隙中部兩側區(qū)域當預制裂隙角度為0°和45°時紅外溫度呈下降狀態(tài),降溫幅度為0.03~0.09℃。當預制裂隙為75°時,預制裂隙中部上方區(qū)域溫度曲線呈現(xiàn)降溫狀態(tài),降溫幅度達0.05℃;而中部下方區(qū)域的溫度曲線呈現(xiàn)上升狀態(tài),降溫幅度達0.08℃。(3)最高紅外輻射溫度曲線前兆規(guī)律主要表現(xiàn)為:降溫前兆,紅外溫度降溫幅度為0.05~0.2℃;升溫前兆,紅外溫度升溫幅度為0.1~0.3℃。平均紅外輻射溫度曲線前兆變化主要表現(xiàn)為:升溫加速、降轉升和升轉降三種類型。其中對于最高紅外輻射溫度曲線前兆,試樣預制裂隙角度為0°~60°時,載荷比基本都落在73~88%區(qū)間內,75°、90°時,主要集中在90%左右。(4)隨著預制裂隙角度的增加,裂隙周圍高應力區(qū)域面積逐漸增大;同時裂紋起裂強度越來越高,試樣破壞強度也越來越大,試樣的承載能力在不斷增強。預制裂隙角度的增加使得聲發(fā)射分布越來越分散。(5)試樣表面紅外輻射溫度場變化與應力場的變化相對應;試樣發(fā)生主破裂前紅外輻射溫度云圖表現(xiàn)出的局部高溫/低溫區(qū)域可以很好的推測將要發(fā)生破壞的位置及主要破壞形式;同時試樣表面紅外溫度場高溫區(qū)域面積急劇下降的變化為試樣的紅外熱像失穩(wěn)前兆。
[Abstract]:Infrared radiation is a geophysical method for monitoring the dynamic disasters of coal and rock. Its infrared temperature and infrared thermal image have the advantages of reflecting the change of time and spatial evolution of coal and rock compression failure. In order to further study the infrared thermal effect of fractured sandstone under load and its precursor law, an experimental system of infrared thermal effect of fractured sandstone is set up, and the infrared radiation at different angles of fracture is measured. According to the measurement results, the different indexes of infrared radiation temperature under uniaxial compression of fractured sandstone are analyzed, and the simulation experiments of stress field, dynamic distribution of acoustic emission and axial displacement field under different fracture angles are carried out. The evolution characteristics of the temperature field at the critical moment before the instability of the sample are compared and analyzed by using the infrared radiation isoline cloud diagram. The results of the study show that: 1) the experimental results show that the temperature field evolves at the critical moment before the instability of the sample. The infrared radiation temperature has a good response to the rupture during the loading failure process. The abnormal signal of MIRT (maximum infrared radiation temperature) shows a sudden increase, and the sudden drop of AIRT (mean infrared radiation temperature) shows the whole down-turn or upturn. When the unstable fracture of sandstone specimen occurs, the temperature increasing range of the highest infrared temperature increases first and then decreases with the increase of angle, and the variation range is 0.14 ~ 1.36 ~ 0.11 鈩，

本文編號：1946366