聚丙烯纤维砂浆拉伸试验及三维分形破裂面分析*
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（金陵科技学院建筑工程学院， 南京 211169）［摘要］运用分形理论及递归算法编制VB程序，随机构造出纤维砂浆拉伸试件三维分形破裂面进行分析。结果表明，聚丙烯纤维水泥基材拉伸承载力由水泥基材三维破裂面正截面承载力、水泥基材三维破裂面拉力方向截面承载力以及聚丙烯纤维水泥基材粘结力三部分构成，较未掺纤维试件仅有水泥基材正截面承载力有所提高。采用所提出的三维分形破裂面的分析方法随机统计分析了聚丙烯纤维砂浆试件的直接拉伸承载力，与试验值相差在5%以内。因此，水泥基材中大量乱向分布的低弹性模量纤维能够阻碍裂缝的扩展，形成更为复杂的破裂面，提高了纤维水泥基材的抗拉强度。［关键词］聚丙烯纤维; 分形; 递归算法; 拉伸承载力; 补强作用机理中图分类号：TU521 文献标识码：A 文章编号：1002-848X(2014)22-0082-04Tensile test of polypropylene fiber mortar and three-dimensional fractal fracture surface analysisXuan Weihong, Wang Yan, Chen Yuzhi, Wang Panxiu, Chen Xiaohong, Wang Yao（Architectural Engineering Institute, Jinling Institute of Technology, Nanjing 211169, China）Abstract: By using the fractal theory and the recursive algorithm VB program, a threedimensional fractal fracture surface of a fiber mortar tensile test specimen was randomly constructed and analyzed. Research results show that the tensile bearing capacity of polypropylene fiber-cement base material is composed of three parts of the normal section bearing capacity of three-dimensional failure surface based on cement base material, the tensile-directional section bearing capacity of three-dimensional failure surface based on cement base material, and cohesive bearing capacity of polypropylene fiber-cement base material. Compared with test specimens without fiber, only the normal section bearing capacity of three-dimensional failure surface based on cement base material improves. The proposed three-dimensional fractal fracture surface analysis method of random statistical analysis was used to analyze direct tensile bearing capacity of the polypropylene fiber mortar specimen and the error is within 5% compared with test values. Therefore, random-distributed low elastic modulus in cement base material can hinder the crack development and form more complex fracture surface to improve the tensile strength of the fiber cement base material.Keywords: polypropylene fiber; fractal; recursive algorithm; tensile strength; reinforcing mechanism*江苏省产学研联合创新资金项目（BY2012039），金陵科技学院博士启动基金项目（jit-b-201107）。作者简介：宣卫红，博士，教授，Email：xuanwh2004@sina.com。参考文献［1］孙博文. 分形算法与程序设计［M］. 北京: 科学出版社, 2002.［2］李士彬, 汤红卫, 朱慈勉. 钢筋混凝土构件损伤演化的分形行为［J］. 石家庄铁道学院学报, 2006, 19(1): 54-57, 66.［3］YAN A, WU K, ZHANG X. A quantitative study on the surface crack pattern of concrete with high content steel fiber［J］. Cement and Concrete Research, 2002, 32(9): 1371-1375.［4］曹茂森, 任青文, 翟爱民, 等. 混凝土结构损伤的分形特征实验分析［J］. 岩土力学, 2005, 26(10): 1570-1574.［5］张衡. 混凝土分形断裂行为及损伤本构研究［D］. 广州：华南理工大学, 2010.［6］郑山锁, 任梦宁, 谢明, 等. 混凝土断裂面多重分形谱的二次拟合研究［J］. 工程力学, 2013, 30(5): 97-102.［7］孙洪泉, 魏超义, 丁俊, 等. 骨料粒径变化的混凝土梁断裂面的分形研究［J］. 工程力学, 2013, 39(3): 39-41.［8］曾庆敦. 复合材料的细观破坏机制与强度［M］. 北京:科学出版社, 2002: 159-160.［9］林小松, 杨果林. 钢纤维高强与超高强混凝土［M］. 北京: 科学出版社, 2002.［10］DL/T 5150—2001 水工混凝土试验规程 ［S］. 北京: 中国电力出版社, 2002.
