Abstract: During the construction stage, the large-segment steel arch rib is subjected to solar radiation, generating a non-uniform temperature field, which causes deformation of the closure section and makes closure process difficult. A thermal control method using coatings with different thermal properties in different zones was proposed to reduce the temperature difference and deformation. This method accurately simulated the three-dimensional temperature field under solar radiation by finite element software. And an area dividing method for the surface of bridges was proposed, and secondary development of the ABAQUS post-processing was conducted using the Python language to clarify the evaluation indicators and ultimately determine the optimized coating scheme for the arch ribs. The ABAQUS-FILM/DFLUX subroutine was used to simulate the three-dimensional temperature field over 24 hours, and the bridge surface was divided into 54 zones based on the angle of the surface normal vectors. Through the Python secondary development, a linear mapping between temperature data and coating radiation absorption rate was realized. It is concluded that at the most unfavorable moment, the partition range is decreased from 17.9 ℃ to 9.7 ℃, the standard deviation is decreased by 50.5%, and the maximum displacement of the closure section is reduced from 26 cm to 7.7 cm. The zonal coating strategy significantly mitigates the inhomogeneous temperature effect under solar radiation and provides technical support for the lifting of large-span sections without closure segments.

Key words: bridge engineering; steel arch bridge; thermal insulation coating; construction control; temperature effect; finite element simulation

摘要： 大节段钢拱肋在施工阶段受日照作用下，产生非均匀温度场，引起合龙截面变形，导致合龙困难。提出通过分区利用不同热工性能涂层的热调控方法，降低温差与变形。该方法给出了使用有限元软件精确模拟日照作用下三维温度场，提出了桥梁表面区域划分的方法，并通过Python语言对ABAQUS后处理进行二次开发，明确了衡量指标，并确定了拱肋涂层优化方案。采用ABAQUS-FILM/DFLUX子程序模拟24 h三维温度场；基于表面法向量角度划分了54个区域；通过Python二次开发实现温度数据-涂层辐射吸收率线性映射。结论由最不利时刻分区极差从17.9 ℃降至9.7 ℃，标准差降低50.5%；合龙截面最大位移从26 cm降至7.7 cm。分区涂层策略显著削弱了日照作用下的非均匀温度效应，为无合龙段大节段提升提供了技术支撑。

关键词: 桥梁工程；钢拱桥；隔热涂层；施工控制；温度效应；有限元模拟