Numerical investigation of temperature gradient-induced thermal stress for steel–concrete composite bridge deck in suspension bridges

Abstract

A 3D finite element model (FEM) with realistic field measurements of temperature distributions is proposed to investigate the thermal stress variation in the steel–concrete composite bridge deck system. First, a brief literature review indicates that traditional thermal stress calculation in suspension bridges is based on the 2D plane structure with simplified temperature profiles on bridges. Thus, a 3D FEM is proposed for accurate stress analysis. The focus is on the incorporation of full field arbitrary temperature profile for the stress analysis. Following this, the effect of realistic temperature distribution on the structure is investigated in detail and an example using field measurements of Aizhai Bridge is integrated with the proposed 3D FEM model. Parametric studies are used to illustrate the effect of different parameters on the thermal stress distribution in the bridge structure. Next, the discussion and comparison of the proposed methodology and simplified calculation method in the standard is given. The calculation difference and their potential impact on the structure are shown in detail. Finally, some conclusions and recommendations for future bridge analysis and design are given based on the proposed study.

摘要

对钢–混组合结构温度梯度效应的研究, 主要是以竖向温度梯度结合二维有限元模型开展的; 而对大跨度桥梁实测温度梯度的研究发现, 其具有典型的空间特性。 鉴于此, 以矮寨大桥为研究背景, 对大跨度悬索桥钢–混组合桥面系的周年实测空间温度梯度进行实测研究, 建立大跨度悬索桥钢–混组合桥面系的空间有限元节段模型, 研究在空间温度梯度耦合作用下, 桥面系结构参数与力学响应之间的关系, 得出的结论可为同类结构的建养提供有益的参考。