發(fā)布時(shí)間：2018-03-13 15:28

  本文選題：爆炸力學(xué)　切入點(diǎn)：裂紋　出處：《爆炸與沖擊》2016年03期 　論文類(lèi)型：期刊論文

【摘要】：為探尋非鉆孔條件下露天爆破大塊二次破碎形態(tài)的控制方法,應(yīng)用線性聚能射流對(duì)圓柱混凝土模型試件進(jìn)行侵徹實(shí)驗(yàn),使用High-speed 3DDIC(高速三維數(shù)字圖像相關(guān)方法)方法分析試件劈裂發(fā)展過(guò)程的全場(chǎng)三維形變特征。研究結(jié)果表明,數(shù)據(jù)分析區(qū)內(nèi)劈裂裂紋擴(kuò)展速度在4個(gè)區(qū)間內(nèi)呈階梯式變化趨勢(shì),峰值速度為235.52m/s,平均速度為140.89m/s;線性聚能射流侵徹對(duì)劈裂裂紋擴(kuò)展有明顯導(dǎo)向作用,應(yīng)力集中作用使得劈裂裂紋圍繞線性射流侵徹對(duì)稱(chēng)軸擴(kuò)展,擴(kuò)展方向變化幅度較小;在劈裂裂紋擴(kuò)展速度突變的3個(gè)時(shí)刻,劈裂裂紋路徑產(chǎn)生了3處明顯拐點(diǎn),在拐點(diǎn)處伴隨有支裂紋的產(chǎn)生,支裂紋的擴(kuò)展距離均未超過(guò)5cm;主應(yīng)變集中帶形狀及分布位置決定了裂紋擴(kuò)展路徑及趨勢(shì),拉應(yīng)變集中先于裂紋出現(xiàn),試件呈現(xiàn)準(zhǔn)靜態(tài)劈裂形態(tài),劈裂面平整度較高。
[Abstract]:In order to explore the control method of the secondary breakage of large blocks in open-air blasting under the condition of non-drilling, the penetration experiments of cylindrical concrete model specimens were carried out by using linear shaped jet. The full-field 3-D deformation characteristics of the splitting development process of the specimen are analyzed by using High-speed 3D DDIC (High Speed 3D Digital Image correlation method). The results show that the crack propagation velocity in the data analysis area shows a step by step trend in four regions. The peak velocity is 235.52 m / s and the average velocity is 140.89 m / s. The penetration of linear shaped jet has an obvious guiding effect on the crack propagation, and the stress concentration makes the crack propagate around the symmetrical axis of the linear jet, and the direction of the crack changes slightly. At three times of sudden change of crack propagation velocity, there are three obvious inflection points in the crack path, and the crack is accompanied by a crack at the inflection point. The propagation distance of the supported crack is not more than 5 cm, the shape and distribution of the main strain concentration zone determines the path and trend of the crack growth, the tensile strain concentration appears before the crack, the specimen presents quasi-static split shape, and the plane flatness is higher.
【作者單位】： 遼寧科技大學(xué)礦業(yè)工程學(xué)院;北京理工大學(xué)爆炸科學(xué)與技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室;
【基金】：國(guó)家自然科學(xué)基金青年科學(xué)基金項(xiàng)目(51504129)
【分類(lèi)號(hào)】：O346.1
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本文編號(hào)：1606988