摘要
建立了混凝土等准脆性材料的Ⅰ-Ⅱ复合型裂缝在单向拉伸荷载作用下断裂角的修正剪滞模型,得到了与试验相吻合且优于传统S判据的断裂角．合理简化了复合型裂缝试样的力学边界条件,得到了裂缝体各剪滞子层位移分布函数的解析表达式．引用一种所谓的最大应力集中因子的概念,对Ⅰ-Ⅱ复合型裂缝前缘应力场进行了简化描述．得到了复合裂缝断裂角的解析解．根据斜裂缝体的应力分布概况,设置不同的子层分区,得到了更为细化的子层位移分布模式．通过对计算数据的分析,提出了合理的按应力场分区设置子层的剪滞分析模型,从而得到了更为精确的斜裂缝断裂角．新方法的计算结果与试验结果除个别外的相对误差小于4％,均小于S判据,显示算法的卓越性．
The modified shear-lag model is built to obtain the fracture angle of Ⅰ-Ⅱ mixed-mode crack under simple tension load. The results obtained in this model are compatible with the experimental data and more precise than the S criterion. The mechanical boundary conditions of the mixed-mode crack specimen are simplified reasonably. Then the analytical displacement functions of sub-layers are obtained. The notion of maximum stress concentration factor is introduced to describe the stress field of crack tip simplified, which is also used to obtain the analytical solution of fracture orientation of Ⅰ-Ⅱ mixed-mode crack. Some special sub-layer zones are used to obtain more precise calculation results according to the analysis and the singularity character around crack tip, which also makes the building of shear-lag model more convenient. The result demonstrates that the relative error between experiment and the calculation result is less than 4% except a few cases. Furthermore, the calculation result is more compatible with the experiment than S criteria, which confirms that the calculation model is more excellent.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2006年第z1期118-125,共8页
Journal of Dalian University of Technology
基金
国家杰出青年科学基金资助项目(50425824).
关键词
剪滞理论
混凝土
断裂角
Ⅰ-Ⅱ复合型裂缝
应力集中因子
shear-lag theory
concrete
fracture angle
Ⅰ-Ⅱ mixed-mode crack
stress concentration factor
