基于ANSYS二次开发的大跨桥梁疲劳寿命与失效概率的可视化技术

Visualization for fatigue life and failure probability of long-span bridges based on secondary development of ANSYS

针对ANSYS软件不能对变幅荷载条件下的大跨桥梁疲劳进行模拟分析的问题,利用ANSYS软件自带的参数化程序设计语言(APDL)及MATLAB程序,对ANSYS软件的疲劳分析功能模块进行二次开发,开发了相应的功能模块用以导出应力时程,结合三峰谷计数法循环计数,依据材料应力-寿命(S-N)曲线和Miner累积损伤理论,估算出大跨桥梁各个部件的疲劳寿命及相应的疲劳失效概率,以三维云图形式实现移动车载作用下大跨桥梁所有构件的疲劳寿命和疲劳失效概率可视化.在现有服役交通荷载作用下,随大跨桥梁承受汽车荷载的增加,大跨桥梁的疲劳失效概率逐渐增大.

To solve the problem that ANSYS cannot simulate the fatigue of large span bridge under variable-amplitude load condition, a new method was proposed using APDL and MATLAB , and thesecondary development of fatigue module was conducted in ANSYS. The corresponding functional module was developed to export the time history of stress and count the loop number withvalleys＇ theory , and the fatigue life was calculated by S-N curve and Miner damage cumulative rule. The fatigue life and the failure probability of large span bridge were presented , and the visualization of whole fatigue life and fatigue failure probability at moving load was carried out by secondary developmentfunction. The result shows that at the existing traffic load , the damage probability is gradually increasedwith the increasing of load.