钢-混凝土组合梁收缩和徐变影响分析和计算.PDFVIP

第 36 卷 建 筑 结 构 2006 年增刊 pp: 9-8~11 钢-混凝土组合梁收缩和徐变的影响分析和计算 孙海林 叶列平 陆新征 （清华大学土木工程系，北京，100084） [摘 要] 本文采用纤维模型编制了有限元程序，利用 MC90 收缩和徐变模型对简支钢-混凝土组合梁在长期荷载作用下的 变形进行了分析，计算结果与试验结果相吻合。论文同时对现行规范方法和文献方法进行了分析，现行规范中考虑收缩和 徐变的计算方法不全面，且偏于不安全，而文献的其它方法在收缩变形分析中也存在一些不足。为此，本文基于所建议的 数值模型对影响组合梁长期变形的收缩和徐变参数进行了分析，并根据徐变和收缩引起的长期变形的机制，建议徐变变形 计算采用“有效弹性模量”的换算截面法，收缩变形采用直接法计算，使得计算概念更为合理，且比现有方法与试验结果 吻合更好。 [关键词] 钢-混凝土组合梁 收缩 徐变 纤维模型 长期变形 有效模量 Long Term Deformation Analysis of Shrinkage and Creep of Steel-Concrete Composite beams SUN Hai-lin YE Lie-ping LU Xin-zheng (Department of Civil Engineering, Tsinghua University, Beijing, 100084,China) Abstract: Based on the theory of fiber model, an efficient numerical method to account for the long-term behavior of composite steel-concrete beams is presented, the creep and shrinkage value is proposed by MC90 model. Numerical results are compared with the experimental results and a good agreement reached. It is found that the design methods for the long-term deflection of current Chinese codes are unsafe while other proposed methods have some drawbacks. A simplified approach to evaluate creep and shrinkage effects in simply supported composite beams is presented. The deflection induced by creep is based on effective modulus method and the deflection induced by shrinkage is directly computed. With clear physical concept, the method is more reliable and in good agreement with the test results. Keywords: Steel-concrete Composite Beam; Shrinkage; Creep; Fiber Model; Long-term Deformation; Effective Modulus 1 引言 式中，Ee 为混凝土有效弹性模量，Ec 为初始弹性模 钢-混凝土组合梁（以下简称组合梁）是由钢 量；k 为弹性模量降低系数。