中文摘要：

我国《钢结构设计规范》（GB50017-201X）送审稿初稿中采用调整钢材与混凝土弹性模量比αE考虑混凝土徐变的影响,一般取钢与混凝土的长期弹性模量之比为2αE,但混凝土的徐变和混凝土强度、计算时刻等因素有关,因此该方法并不能准确反映组合梁在长期荷载作用下的变形。考虑影响混凝土徐变的相关因素,对钢-混凝土组合箱梁的长期变形计算进行理论推导,建立钢-混凝土组合箱梁的长期挠度计算公式,采用ANSYS模拟长期荷载作用下组合梁的变形,并通过实际值和模拟值的比较证明本文建模的可行性,然后利用ANSYS模拟长期荷载荷载作用下组合箱梁的变形,将计算值和模拟值进行比较,研究结果表明：采用建议公式计算组合箱梁在任意时刻下的挠度变形可行,且计算方便。

英文摘要：

The ratio of modulus of elasticity of steel to that of concrete termed as αE was modified to consider the influence of the creep of concrete in the updated draft Code for design of steel structures, and the modification value was 2αE. However, the creep of concrete depends on the strength of the concrete, the calculation time, ere; therefore with this method it cannot reflect the deformation of the composite beams exactly under long term loadings. In this paper, the related factors regarding creep of concrete were considered in calculation of the long - term deflection of composite beams, and theoretical derivation was performed. The formula for calculation of long - term deflection of steel - concrete composite beam was then established, and it was also simulated in this paper by ANSYS. The comparisons between the calculated and simulated values indicate that the suggested formula in this paper is feasible to calculate the long - term deflection of composite box - beams.