斜拉桥拉索损伤模拟方法及其对索力和挠度分布规律的影响

Simulation Method for Cable Damage of Cable-Stayed Bridge and Its Effect on Cable Tension and Deflection Distribution

以某独塔斜拉桥为例,分别采用面积折减法、弹模折减法、反向荷载法和实体单元法模拟拉索的断丝损伤,采用实体单元法模拟拉索不同长度和深度的局部锈蚀(未断丝)损伤,分析拉索发生断丝损伤或局部锈蚀损伤后索力及主梁挠度的变化规律。结果表明:面积折减法的概念明确、操作简单,可作为模拟拉索断丝损伤的首选方法;虽然实体单元法建模过程较为复杂,但是它是模拟拉索局部锈蚀损伤的有效方法;拉索发生局部锈蚀损伤时,其索力及主梁挠度的变化幅度比发生断丝损伤的情况小得多,只有当拉索在其全长范围内发生同样的锈蚀损伤时,其索力及梁体挠度的变化与断丝损伤的情况相同。

Taking a single tower cable-stayed bridge as an example,area reduction method,elastic modulus reduction method,reverse loading method and solid element method were adopted to simulate the broken wire damage of cable respectively.Solid element method was also adopted to simulate the local corrosion（not broken wire）damage of cable at different lengths and different depths respectively.The change laws of cable tension and the deflection of main girder after cable broken wire damage or local corrosion damage were analyzed.Results show that area reduction method is of clear concept and simple operation,which can be used as a preferred method for simulating the broken wire damage of cable.Although the modeling process of solid element method is relatively complicated,it is an effective method for simulating the local corrosion damage of cable.When the local corrosion damage of cable occurs,the changes in cable tension and the deflection of main girder are much smaller than those when the broken wire damage of cable occurs.Only when the same corrosion damage occurs within the full length of cable,the changes in cable tension and the deflection of girder are the same as those when broken wire damage takes place.