爆炸聚能作用下混凝土试件劈裂的高速3D DIC实验

发布时间：2018-03-13 15:28

  本文选题：爆炸力学　切入点：裂纹　出处：《爆炸与冲击》2016年03期 　论文类型：期刊论文

【摘要】：为探寻非钻孔条件下露天爆破大块二次破碎形态的控制方法,应用线性聚能射流对圆柱混凝土模型试件进行侵彻实验,使用High-speed 3DDIC(高速三维数字图像相关方法)方法分析试件劈裂发展过程的全场三维形变特征。研究结果表明,数据分析区内劈裂裂纹扩展速度在4个区间内呈阶梯式变化趋势,峰值速度为235.52m/s,平均速度为140.89m/s;线性聚能射流侵彻对劈裂裂纹扩展有明显导向作用,应力集中作用使得劈裂裂纹围绕线性射流侵彻对称轴扩展,扩展方向变化幅度较小;在劈裂裂纹扩展速度突变的3个时刻,劈裂裂纹路径产生了3处明显拐点,在拐点处伴随有支裂纹的产生,支裂纹的扩展距离均未超过5cm;主应变集中带形状及分布位置决定了裂纹扩展路径及趋势,拉应变集中先于裂纹出现,试件呈现准静态劈裂形态,劈裂面平整度较高。
[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.
【作者单位】： 辽宁科技大学矿业工程学院;北京理工大学爆炸科学与技术国家重点实验室;
【基金】：国家自然科学基金青年科学基金项目(51504129)
【分类号】：O346.1
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本文编号：1606988