三点弯曲下混凝土梁挠度与裂缝口张开位移关系
发布时间：2018-08-12 07:29
【摘要】：为研究三点弯曲混凝土梁挠度δ与裂缝口张开位移CMOD的关系,对五组尺寸相同、强度不同的预制切口梁进行三点弯曲试验,获得加载全过程的P-δ曲线和P-CMOD曲线。由于试验中的P-δ曲线和P-CMOD曲线同步测得,取相同P值下对应的δ值与CMOD值,即可得到一一对应的δ值与CMOD关系。分析表明:δ-CMOD关系可分为非线性和线性两部分,采用数值分析确定两部分的拟合参数;针对混凝土强度的影响,提出各参数关于强度的经验公式。最后,通过对不同批次、相同成分的混凝土断裂能对比分析,证实了本文拟合关系的可靠性。采用本文公式由CMOD计算的断裂能G_F~(P-δ(CMOD))的标准偏差为5.93N/m,远小于由挠度实测值计算的断裂能G_F~(P-δ)的标准偏差21.05N/m,且G_F~(P-δ(CMOD))的平均值更接近已知的混凝土的断裂能。
[Abstract]:In order to study the relationship between deflection 未 and crack opening displacement (CMOD) of three-point bending concrete beam, five groups of prefabricated notched beams with the same size and different strength were subjected to three-point bending tests. The P- 未 curves and P-CMOD curves of the whole loading process were obtained. Because the P- 未 curve and P-CMOD curve are measured synchronously, the relation between 未 value and CMOD can be obtained by taking the corresponding 未 value and CMOD value under the same P value. The analysis shows that the 未 -CMOD relation can be divided into two parts: nonlinear and linear, the fitting parameters of the two parts are determined by numerical analysis, and the empirical formula of each parameter about strength is put forward in view of the influence of concrete strength. Finally, the reliability of the fitting relationship is confirmed by comparing and analyzing the fracture energy of concrete with different batches and the same composition. The standard deviation of GSP ~ (P- 未) (CMOD) calculated by CMOD formula is 5.93 N / m, which is much smaller than that of GSP ~ (P- 未) calculated by deflection measurement, and the average value of GSP ~ (P- 未) (CMOD) is closer to the fracture energy of known concrete.
【作者单位】： 贵州大学空间结构研究中心;
【基金】：国家自然科学基金(51408144;51568012) 贵州省科学技术基金项目([2016]1040) 贵州省留学人员科技创新项目(Z164096) 贵州大学引进人才科研基金([2013]01)
【分类号】：TU528
本文编号：2178339
[Abstract]:In order to study the relationship between deflection 未 and crack opening displacement (CMOD) of three-point bending concrete beam, five groups of prefabricated notched beams with the same size and different strength were subjected to three-point bending tests. The P- 未 curves and P-CMOD curves of the whole loading process were obtained. Because the P- 未 curve and P-CMOD curve are measured synchronously, the relation between 未 value and CMOD can be obtained by taking the corresponding 未 value and CMOD value under the same P value. The analysis shows that the 未 -CMOD relation can be divided into two parts: nonlinear and linear, the fitting parameters of the two parts are determined by numerical analysis, and the empirical formula of each parameter about strength is put forward in view of the influence of concrete strength. Finally, the reliability of the fitting relationship is confirmed by comparing and analyzing the fracture energy of concrete with different batches and the same composition. The standard deviation of GSP ~ (P- 未) (CMOD) calculated by CMOD formula is 5.93 N / m, which is much smaller than that of GSP ~ (P- 未) calculated by deflection measurement, and the average value of GSP ~ (P- 未) (CMOD) is closer to the fracture energy of known concrete.
【作者单位】： 贵州大学空间结构研究中心;
【基金】：国家自然科学基金(51408144;51568012) 贵州省科学技术基金项目([2016]1040) 贵州省留学人员科技创新项目(Z164096) 贵州大学引进人才科研基金([2013]01)
【分类号】：TU528
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1 王秋雨;基于进化算法的三点弯曲梁混凝土软化本构关系研究[D];浙江工业大学;2012年
，本文编号：2178339
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