摘要
通过对不同高径比圆盘试样进行巴西劈裂试验发现,随着高径比的增加,抗拉强度逐渐减小,呈近似三次函数关系。然而由于巴西劈裂抗拉强度是基于弹性力学平面假设得到的,与实验结果存在较大差异,同样给尺寸效应研究带来困扰。采用有限差分软件对不同高径比圆盘试样应力分布规律进行研究,结果表明:越靠近端部,水平应力越大;高径比越大,圆盘端面中点处水平拉应力越大;圆盘起裂位置发生在端面中心点而不是内部中心点。在此基础上对巴西圆盘劈裂试验方法进行修正,获得更加真实的抗拉强度尺寸效应。
The laws, tensile strength decreases gradually with the increase of hight -to -diameter ratio and the change curve can be better simulated with a cubic function, have been found through splitting tensile test on a large number of disc specimens with different hight - to - diameter ratios. However, as the Brazil splitting tensile strength is based on the assumption of plane in elastic mechanics, there are great differences between the calculated results and the actual three - dimensional experimental results, and it also brings trouble to the research on the dimensional effect. The stress distribution rules of disc specimens with different hight - to - diameter rati- os through FLAC3D shows that the more close to the ends, the higher of the horizontal stress ; the larger of the hight - to - diameter ratio is, the higher of the horizontal stress of the central point of the specimens ; the first fracture starting point is at the center of the ends rather than at the internal center point. Based on which test results of Brazil split can be revised to get a more real dimensional effect of the tensile strength.
出处
《煤矿安全》
CAS
北大核心
2014年第4期17-20,共4页
Safety in Coal Mines
基金
国家级大学生创新训练计划资助项目(201210290009)
国家重点基础研究发展计划(973计划)资助项目(2013CB036003)
江苏省普通高校研究生科研创新计划资助项目(CXZZ13_0935)
关键词
巴西劈裂
平面假设
抗拉强度
高径比
修正系数
Brazilian splitting
plane cross - section assumption
tensile strength
ratio of hight - to - diameter
correction coefficient
