城市轻轨槽型梁温度效应及裂缝分析

The groove beam of urban light rail temperature effect and fracture analysis

以城市轻轨槽型梁为研究对象,采用精细化有限元方法研究温度效应及裂缝成因对槽型梁力学性能的影响,结果表明:竖向温度梯度对槽型梁竖向位移、纵向应力、横向应力均有较大影响,设计中不能忽略;系统温差只引起槽型梁变形,不引起应力,横向位移和纵向位移都是随着系统温差的增大而线性增加;普通钢筋可以抑制裂缝的发展,进行非线性分析时,除考虑材料非线性,还必须建立含普通钢筋的精细化模型,在预应力张拉后,锚固端裂缝分布最多,施工时可以在1/8跨径范围内采取补强措施来避免预应力张拉产生的裂缝。

By taking the light rail groove beam in zhengzhou city as an example,the effects of temperature effect and cracks causes on the mechanical properties of the groove beam were studied by using the finite element method.The calculation results show that the vertical temperature gradient,vertical displacement of the U-shaped beam longitudinal stress and transverse stress have relatively large impact force,and cannot be neglected in the design of the system;only groove beam deformation caused by the temperature stress does not.Lateral displacement and longitudinal displacement increase with temperature,and the deformation value grows linearly.Ordinary reinforcement can inhibit the development of cracks with nonlinear analysis not only considering the material nonlinear,but also establishing fine model of ordinary reinforcement.After prestressed steel bar is tensioned,cracks are mainly distributed at the anchorage end.During construction,within the scope of 1/8 of span,reinforcement measures are taken to avoid the prestressed tension cracks.