斜拉桥索梁锚固结构疲劳试验模型设计优化

Design optimization of fatigue test model for the cable-girder anchorage zone of steel cable-stayed bridges

为了避免出现斜拉桥索梁锚固结构疲劳试验中辅助部分首先断裂的问题,在以往试验模型设计的基础上,考虑影响疲劳寿命的不同因素,建立了以模型的静力强度、位移、疲劳和断裂性能为模糊约束条件,以模型质量、疲劳和断裂寿命为多个目标的结构多目标优化设计模型.结合苏州-南通长江公路大桥钢锚箱式索梁锚固结构足尺疲劳试验,验证了锚箱式索梁锚固结构设计的正确性,经过400万次加载而未破坏,且减少了模型用钢量.模型设计中提出的控制热点应力等措施切实可行.

To avoid the first break of the accessorial structure in fatigue model test for the cable-girder anchorage zone of steel cable-stayed bridges, based on a few former fatigue test designs, a multiobjective optimum structural model which takes into account various factors affecting the fatigue life is established. This model design takes the static strength, displacement, fatigue and fracture performance as its fuzzy constraint conditions. The structural weight, fatigue and fracture lives are taken as the objectives of this design. A full scale static and fatigue model test of the cable-girder anchorage zone of Suzhou-Nantong Yangtze River Bridge was carried out. The results of model test verify the correctness of its design. The fatigue model of the anchorage system is not destroyed under 4 millions cyclic loads, and the amount of steel used for the model test is reduced. The methods such as hot spot stresses control in this model design are practical.