(1 重庆大学土木工程学院， 重庆 400045； 2 中国建筑科学研究院有限公司， 北京 100013)

［摘要］随着结构中钢筋混凝土偏心受压柱长细比、材料强度和轴压力的增大，压杆发生失稳失效的风险在增长，但在各国至今使用的混凝土结构设计规范中均未见给出在已知等效长度的前提下单杆非线性失稳峰值承载力的计算方法。为此，利用非线性有限元软件ABAQUS完成了在各主导参数常用变化范围内的足够数量钢筋混凝土偏心受压柱模拟分析计算。以此为数据集，在取用规范规定的强度失效承载力表达式作为强度失效模型的前提下，通过回归分析，以调整系数-作为主要辅助手段，给出了表达钢筋混凝土偏心受压柱从强度失效到失稳失效连续过渡的非线性极限承载力实用表达式。并用到目前为止能收集到的在可靠试验条件下完成的以细长压杆为主的试验结果对所提通用公式的准确性进行了识别。利用建立的非线性分析模型还可完成给定参数条件下相应压杆失效类型的识别。

［关键词］钢筋混凝土； 细长偏心压杆； 非线性失稳极限承载力

中图分类号：TU375-3文献标识码：A文章编号：1002-848X(2019)05-0100-09

Study on nonlinear buckling bearing capacity of reinforced concrete   eccentrically compressed long column

Bai Shaoliang1, Gong Huaxu1, Wang Min1, Zhu Aiping2

(1 School of Civil Engineering, Chongqing University, Chongqing 400045, China; 2 China Academy of Building Research, Beijing 100013, China)

Abstract:With the increase of the slenderness ratio, the material strength and the axial pressure of the reinforced concrete eccentrically compressed column, the risk of instability failure of the compression member increases, but the calculation method for nonlinear buckling ultimate bearing capacity of the compression member on the premise of known equivalent length have not been given by the concrete structure design code used in various countries. The nonlinear finite element software ABAQUS was used to simulate and calculate a sufficient number of the reinforced concrete eccentrically compressed columns in the range of the common parameters. Based on this data set and regression analysis, the practical expression for the nonlinear ultimate bearing capacity of reinforced concrete eccentrically compressed column was given on the premise of accessing the expression for strength failure bearing capacity specified in the current code as the strength failure model, which could apply to the continuous transition from the strength failure to the instability failure, with adjusted factor - as a major means of auxiliary. The accuracy of the proposed general expression has been identified by the test results mostly based on compression slender members which could be collected under the condition of reliable test up to now. Under the condition of given parameters, the nonlinear analysis model could also be used to identify the failure type of the corresponding compression member.

Keywords:reinforced concrete; slender eccentrically compressed member; nonlinear buckling ultimate bearing capacity

作者简介：白绍良，博士，教授，博士生导师，Email：Shaoliangbai@126.com。