【摘要】：爆破方法具有高效率、低成本等特點(diǎn),因而在礦山、土木和油氣等工程中得到了廣泛的應(yīng)用,因此研究爆破特別是鉆孔爆破致裂機(jī)理具有很重要的理論意義和應(yīng)用價(jià)值。本文主要研究脆性材料(巖石和混凝土)在爆炸沖擊載荷作用下的開裂行為,通過理論分析、數(shù)值模擬和實(shí)驗(yàn)研究對(duì)鉆孔爆炸致裂問題進(jìn)行了較系統(tǒng)的研究,主要內(nèi)容包括以下幾個(gè)方面： 鉆孔裝藥爆炸后在距爆源不同的距離會(huì)產(chǎn)生破碎區(qū)、開裂區(qū)和彈性區(qū),根據(jù)這三種不同的材料響應(yīng)行為建立了一種空穴膨脹理論模型,該模型與以前的空穴膨脹模型相比,不同點(diǎn)是空腔初始半徑不為0,而是一個(gè)有限值。同時(shí)在模型中考慮了剪脹效應(yīng),這樣一來在破碎區(qū)內(nèi)不僅可以描述脆性材料的壓縮狀態(tài),也可以描述材料的膨脹狀態(tài)。文中還將理論計(jì)算結(jié)果與利用實(shí)驗(yàn)室自己開發(fā)的材料本構(gòu)模型進(jìn)行的數(shù)值模擬結(jié)果進(jìn)行了比較,發(fā)現(xiàn)這兩種方法計(jì)算得出的空穴壁面處的徑向應(yīng)力大小比較一致。而且通過空穴膨脹模型還可以得出使空穴發(fā)生膨脹行為的臨界徑向應(yīng)力。 建立了二級(jí)鉆地彈的侵徹分析模型,研究了靶體中預(yù)制孔道直徑大小與彈體侵徹深度之間的關(guān)系,并與實(shí)驗(yàn)結(jié)果進(jìn)行對(duì)比,發(fā)現(xiàn)兩者吻合得很好；優(yōu)化了二級(jí)戰(zhàn)斗部系統(tǒng),并得到了最優(yōu)侵徹深度與撞擊速度、隨進(jìn)彈與前置裝藥直徑之比之間的關(guān)系。 數(shù)值模擬分析了載荷特性如載荷峰值、加載率和卸載率對(duì)鉆孔周圍破碎區(qū)和開裂區(qū)范圍大小產(chǎn)生的影響。研究發(fā)現(xiàn)如果載荷峰值過高會(huì)在鉆孔周圍形成較大范圍的破碎區(qū),造成載荷能量的浪費(fèi),對(duì)宏觀連貫性裂紋的擴(kuò)展延伸沒有產(chǎn)生積極的作用；如果載荷峰值過低,鉆孔周圍介質(zhì)中的環(huán)向應(yīng)力不足以引起徑向裂紋的產(chǎn)生,不利于宏觀裂紋的生成。研究還發(fā)現(xiàn)在相同沖量的條件下,梯形載荷比三角形載荷的致裂效果好一些,并且載荷的加載率和卸載率對(duì)裂紋的數(shù)目和長(zhǎng)度有很大的影響,加載率越高同時(shí)卸載率越低,產(chǎn)生的宏觀裂紋越長(zhǎng),但是裂紋數(shù)目越少。當(dāng)使空穴發(fā)生膨脹行為的臨界徑向應(yīng)力作為載荷峰值的下界時(shí),能夠產(chǎn)生較好的致裂效果。 利用實(shí)驗(yàn)室自己開發(fā)的脆性材料本構(gòu)模型對(duì)花崗巖鉆孔爆炸致裂問題進(jìn)行了數(shù)值模擬研究,并與文獻(xiàn)中報(bào)導(dǎo)的實(shí)驗(yàn)結(jié)果和實(shí)驗(yàn)室自己的實(shí)驗(yàn)結(jié)果進(jìn)行了比較。結(jié)果表明該本構(gòu)模型能夠較好地模擬脆性材料(巖石、混凝土)在動(dòng)態(tài)沖擊載荷下的損傷開裂行為。 采用數(shù)值模擬方法研究了裂紋內(nèi)爆生氣體驅(qū)使裂紋擴(kuò)展的過程,并對(duì)裂紋內(nèi)高壓氣體的分布、裂紋不同位置的張開位移進(jìn)行了分析,研究發(fā)現(xiàn)：裂紋密度越大,驅(qū)使裂紋擴(kuò)展所需要的臨界壓力也越高；高壓氣體浸入裂紋內(nèi)并在孔內(nèi)膨脹做功的聯(lián)合作用與只考慮高壓氣體浸入裂紋內(nèi)的單獨(dú)作用相比,前者的致裂效果稍好一些。
[Abstract]:Because of its high efficiency and low cost, blasting method has been widely used in mining, civil engineering, oil and gas engineering, etc. Therefore, it is of great theoretical significance and application value to study the mechanism of blasting, especially in drilling blasting. In this paper, the cracking behavior of brittle materials (rock and concrete) under explosive impact load is studied. Through theoretical analysis, numerical simulation and experimental study, the problem of borehole explosion cracking is studied systematically. The main contents include the following aspects: a hole expansion theoretical model is established according to the response behavior of the three different materials, such as the fragmentation zone, the crack zone and the elastic zone, which will occur at different distances from the explosion source after the drilling charge explodes, and the theoretical model of hole expansion is established according to the response behavior of these three kinds of materials. The difference between the model and the previous cavity expansion model is that the initial radius of the cavity is not 0 but a finite value. At the same time, the shear expansion effect is taken into account in the model, so that not only the compressive state of brittle material can be described, but also the expansion state of the material can be described in the broken zone. The theoretical calculation results are compared with the numerical simulation results by using the material constitutive model developed by ourselves in the laboratory. It is found that the radial stresses calculated by these two methods are in good agreement with those obtained on the surface of the cavity wall. The critical radial stress of the cavity expansion behavior can also be obtained by the cavity expansion model. The penetration analysis model of two-stage ground drilling projectile is established. The relationship between the diameter of prefabricated holes in the target and the penetration depth of the projectile is studied, and compared with the experimental results, it is found that the two are in good agreement with each other. The second-level warhead system is optimized, and the relationship between the optimal penetration depth and impact velocity, the ratio of projectile-to-precharge diameter is obtained. The effects of load characteristics, such as peak load, loading rate and unloading rate, on the area of fracture and fracture around borehole are analyzed by numerical simulation. It is found that if the peak value of load is too high, a large area of fragmentation will be formed around the drilling hole, resulting in a waste of load energy and no positive effect on the propagation and extension of macro-coherent cracks. If the load peak is too low, the circumferential stress in the surrounding media is not enough to cause radial cracks, which is not conducive to the formation of macro-cracks. It is also found that under the condition of the same impulse, the trapezoidal load is better than the triangular load, and the loading rate and unloading rate of the load have a great effect on the number and length of cracks, and the higher the loading rate, the lower the unloading rate, and the higher the loading rate and the lower the unloading rate, the higher the loading rate and the lower the unloading rate. The longer the macro cracks are produced, the less the number of cracks is. When the critical radial stress of the cavity expansion behavior is used as the lower bound of the peak load, a better fracturing effect can be obtained. In this paper, the constitutive model of brittle materials developed by the laboratory is used to simulate the explosion cracking of granite drilling holes, and the results are compared with the experimental results reported in the literature and the experimental results in the laboratory. The results show that the constitutive model can simulate the damage and cracking behavior of brittle materials (rock and concrete) under dynamic impact load. The process of crack propagation driven by crack explosion gas is studied by numerical simulation method. The distribution of high pressure gas in crack and the opening displacement of crack at different positions are analyzed. It is found that the crack density increases with the increase of crack density. The higher the critical pressure is needed to drive the crack propagation; The combined action of high pressure gas immersion into the crack and expansion in the hole is better than that of only considering the single action of high pressure gas immersion into the crack, the former is a little better than that of the high pressure gas immersion in the crack.
【學(xué)位授予單位】：中國(guó)科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2013
【分類號(hào)】：X932

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 龔敏,王德勝,程西江;條形藥包不同空腔比試驗(yàn)研究[J];爆破;2004年04期

2 葛濤,吳華杰,陶劍青,王明洋;巖石中爆炸破碎區(qū)邊界參數(shù)研究[J];爆破;2005年03期

3 宗琦;巖石內(nèi)爆炸應(yīng)力波破裂區(qū)半徑的計(jì)算[J];爆破;1994年02期

4 張志呈;巖體爆破裂紋擴(kuò)展速度實(shí)驗(yàn)研究[J];爆破器材;2000年03期

5 龍?jiān)?條形裝藥土中爆炸沖擊波及空腔的數(shù)值模擬[J];爆炸與沖擊;1990年01期

6 張奇;巖石爆破的粉碎區(qū)及其空腔膨脹[J];爆炸與沖擊;1990年01期

7 楊小林,王夢(mèng)恕;爆生氣體作用下巖石裂紋的擴(kuò)展機(jī)理[J];爆炸與沖擊;2001年02期

8 盧文波，，陶振宇;預(yù)裂爆破中炮孔壓力變化歷程的理論分析[J];爆炸與沖擊;1994年02期

9 盧文波，陶振宇;爆生氣體驅(qū)動(dòng)的裂紋擴(kuò)展速度研究[J];爆炸與沖擊;1994年03期

10 顏事龍,馮叔瑜,金孝剛;有機(jī)玻璃中條形藥包爆炸破碎區(qū)發(fā)展過程的高速攝影研究[J];爆炸與沖擊;1998年03期

相關(guān)博士學(xué)位論文 前2條

1 楊漢武;爆炸磁壓縮發(fā)生器及其脈沖功率調(diào)制研究[D];中國(guó)人民解放軍國(guó)防科學(xué)技術(shù)大學(xué);2002年

2 何濤;動(dòng)能彈在不同材料靶體中的侵徹行為研究[D];中國(guó)科學(xué)技術(shù)大學(xué);2007年

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