重组竹Ⅱ型断裂特性试验研究  

Experimental study on mode-Ⅱ fracture characteristics of parallel strand bamboo

作　　者：黄东升[1] 潘文平 周爱萍[1] 王骁睿[1,2] 许嘉诺 Huang Dongsheng;Pan Wenping;Zhou Aiping;Wang Xiaorui;Xu Jianuo(National-Provincial Joint Engineering Research Center of Biomaterials,Nanjing Forestry University,Nanjing 210037,China;Faculty of Forestry and Environment Management,University of New Brunswick,New Branswick E3B5A3,Canada;School of Architecture,Nanjing TECH University,Nanjing 211800,China)

机构地区：[1]南京林业大学生物质材料国家地方联合工程研究中心,南京210037 [2]Faculty of Forestry and Environment Management,University of New Brunswick [3]南京工业大学建筑学院,南京211800

出　　处：《东南大学学报（自然科学版）》2018年第6期1076-1081,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51578291);国家重点研发计划资助项目(2017YFF0207203-04);江苏省高校优势学科建设资助项目

摘　　要：为研究重组竹顺纹Ⅱ型裂纹扩展条件,进行了ENF(end notched flexure)断裂试验.分别采用柔度标定法和修正梁理论计算了临界应变能释放率,对比了2种方法的优缺点,并研究了重组竹顺纹Ⅱ型断裂R曲线,计算了重组竹的断裂韧度.结果表明:重组竹顺纹Ⅱ型裂纹的扩展具有自相似性,构件破坏经历断裂过程区FPZ(fracture process zone)发展和裂纹扩展2个阶段,FPZ的发展使得R曲线在加载初期表现出增长趋势,而裂纹扩展阶段R曲线基本保持水平;临界能量释放率G_(ⅡC)是与初始裂纹长度无关的常数,断裂韧度K_(ⅡC)平均值为4079 kN/m^(3/2),其值大约是常见木材的2倍.To study the Mode-Ⅱfracture characteristics of parallel strand bamboo(PSB)composite,an end notched flexure(ENF)test was conducted.The critical energy release rate was evaluated by a compliance calibration method and the corrected beam theory,respectively.The R-curve and the fracture toughness were obtained.The results show that the crack propagation of mode-Ⅱfracture is self-similar cracking when cracks are parallel to the strand;the fracture process goes through two periods:fracture process zone(FPZ)development and crack propagation;R-curve firstly exhibits an increasing manner with crack growth due to FPZ development,and then the curve becomes approximately horizontal during crack propagation;the critical energy release rate is a constant independent of the initial crack length;the mean value of fracture toughness KⅡc is 4 079 kN/m^3/2,its value is about two times that of common wood products.

关 键 词：重组竹 Ⅱ型断裂 ENF试验 应变能释放率 断裂韧度 R曲线 

分 类 号：TU531.3[建筑科学—建筑技术科学]