预应力混凝土箱梁结构日照温差应力分析

Analysis on Sunlight Differential Temperature Stress of Prestressed Concrete Box Girder Structure

预应力混凝土桥梁受太阳辐射,结构表面至一定厚度范围内将产生温度差,与此同时,梁体自身对其内部纤维形成约束,从而出现温度应力。运用ANSYS软件建立了连续刚构桥主梁实体单元模型,重点考虑温度梯度影响,通过对比分析不同形状梁截面对温度应力的反应,得出腹板与顶板间加腋对腹板因温度梯度引起的拉应力影响甚微。提出腹板温度应力对预应力混凝土桥梁结构的设计过程影响甚重,须加以考虑,可供同型桥梁设计参考。

Prestressed concrete bridges are exposed to solar radiation,and the surface of the structure will have a temperature difference within a certain thickness range.At the same time,the beam itself will constrain its internal fibers,resulting in temperature stress.ANSYS software is used to establish a solid element model of the main girder of a continuous rigid-frame bridge and to focus on the influence of temperature gradient.By comparing and analyzing the response of the different beam sections to the temperature stress,it is resulted that the axils between web and roof have little effect on the tensile stress caused by temperature gradient.It is proposed that the temperature stress of web has great influence on the design process of prestressed concrete bridge structure,which must be considered and can be referred for the design of the similar bridges.