中文摘要：

针对深肋组合扁梁在塑性受力阶段截面应力状态的复杂性，为克服现有的抗弯承载力计算方法较多地依靠工程经验的缺点，文中在对两个简支深肋组合扁梁进行承载试验的基础上，提出了采用等效矩形应力图的计算方法，建立了深肋简支组合扁梁的截面抗弯承载力计算模型，推导了截面抗弯承载力的计算公式，利用现有的试验结果给出了混凝土峰值应力折减系数建议值．试验结果初步验证了所建立的组合扁梁抗弯承载力计算公式的正确性．

英文摘要：

In the plastic stage, the composite-slim beam with deep rib is of a complex stress distribution in its section, so the existing calculation methods of bending resistance depend greatly on engineering experiences. In order to solve this problem, a method, equivalent rectangular stress distribution, is proposed based on the experiments conducted on two simply-supported composite-slim beam specimens. A model for calculating the bending resistance of the beam is then established and the corresponding formulae are derived. Moreover, a reduction coefficient for concrete peak stress is suggested on the basis of the existing experimental results, preliminarily confirming the correctness of the proposed formulae.