文档介绍：华中科技大学
硕士学位论文
某大跨悬索桥抖振动力可靠性研究
姓名:甘文
申请学位级别:硕士
专业:结构工程
指导教师:李黎
20051105
摘要
随着桥梁向大跨轻柔方向发展由紊流风引起的桥梁抖振以及相应的动力可
靠性问题已经成为越来越多学者研究的对象本文在现有抖振理论和动力可靠性理
论的基础上以某大跨悬索桥为工程背景研究了其抖振响应及动力可靠性问题
本文主要完成了以下的工作
首先介绍了抖振时域分析方法内容包括脉动风速场的模拟以及抖振计算的
准定常理论详细推导了根据模拟的脉动风速时程求节点抖振力时程的公式编制
了相应的 APDL 命令流完成了抖振力的实现计算了该悬索桥的风致抖振响应
其次基于首次超越机制在随机过程为平稳正态各态历经过程的基础上
推导了相应的计算单个构件或节点动力可靠度的公式以及应用简化的串联失效模
式计算结构系统抖振动力可靠概率的公式在此基础上采用 5 种不同的可靠度公
式计算了悬索桥主梁上 7 个节点处的可靠概率其中考虑了不同风速不同攻角以及
不同时距的影响比较了主梁各节点可靠概率随风速风攻角时距等的变化情况
并比较了各公式计算的差异最后简单计算了悬索桥主梁系统的可靠概率界限通
过计算认为该悬索桥主梁的首超动力可靠度能够满足刚度的要求
最后在假定结构疲劳寿命服从威布尔分布的基础上推导了相应的疲劳可靠
度公式基于时域抖振计算得出的悬索桥主缆应力时程采用雨流计数法编制了相
应的程序统计了应力脉的频次数在此基础上计算了悬索桥主缆 3 个不同单元的
疲劳可靠概率结果表明该悬索桥主缆有足够的疲劳可靠度
关键词悬索桥抖振时域分析动力可靠度疲劳可靠度
I
Abstract
As bridges grow towards long-span and flexibility, the buffeting of bridges induced
by turbulence and dynamic reliability problems e the research object for more and
more researchers. Based on the current buffeting theory and dynamic reliability theory,
with a long-span bridge taken as an example, this paper focuses on its buffeting responses
and dynamic reliability. This research is focused mainly on the following aspects:
At first, the buffeting analysis method in the time domain is introduced, including the
simulation of the turbulent wind velocity and the Quasi-steady Aerodynamic Forces
theory of buffeting calculation. The formulas for calculating buffeting forces time-history
according to the wind velocity time-history are deduced in details. piled APDL
programs are used to fulfill the wind force, in this way the wind-induced buffeting
responses are calculated.
Secondly, based on the first passage mechanism and on the basis of stationary
normal and ergodic stochastic processes corresponding formulas for calculating dynamic
reliability of ponent or node are deduced, and the formulas are given by
adopting simplified series connection invalidation mode to calculate the structure system
buffeting dynami