基于黏结-滑移效应的钢筋混凝土梁裂缝宽度数值计算

摘要

基于黏结-滑移理论对钢筋混凝土受弯构件裂缝宽度的计算进行说明,指出采用数值计算方法进行分析的必要性.在综合考虑钢筋与混凝土间的黏结-滑移效应、裂缝间混凝土拉伸硬化效应以及材料非线性本构关系等问题的基础上,建立钢筋混凝土梁构件裂缝宽度计算的数值模犁.以8根HRB500级高强钢筋混凝土梁受弯开裂试验为例,将试验结果、规范公式计算结果以及数值模型预测结果进行对比分析.研究结果表明:试验梁短期最大裂缝宽度的模型预测结果与试验结果较符合,两者比值的均值为1.098,变异系数为0.146 5;而规范公式计算值则普遍大于试验值,需要进行适当修正.取等间距开裂的模型梁进行算例分析,得出平均裂缝宽度预测值与规范公式的计算值较吻合,进一步验证了该数值计算模型是一种有效的、准确的裂缝宽度分析方法.%The element principle of bond-slip relation in calculating structural crack width was briefly introduced, and the necessity to adopt numerical analysis was pointed out.Then, a numerical model for analyzing the crack width of reinforced concrete (RC) beams was built, which took bond-slip relationship between concrete and steel bar, tensionstiffening effect of concrete and nonlinear constitutive relationships of materials into account.Based on the experimental results of eight RC beams with 500 MPa steel bars, a comparison between model predictions, test observations and formula calculations was made.The outcome indicates that the predicted results agree well with the test values and the mean and coefficient of variation of their ratios are 1.098 and 0.146 5, respectively.And the calculations are greater than test values and should be modified.Based on analytical example, it can be concluded that the numerical model agrees with code formula in the calculation of mean crack width and it is practical in predicting crack width for RC beams.