论文部分内容阅读
由于结构的非线性以及脉动风荷载的非高斯分布,强风作用下大跨悬索桥的抖振响应并不服从高斯随机过程假设。在桥梁抖振响应精细化时域分析的基础上,充分考虑风荷载及结构自身非线性因素的影响,得到结构的响应时程,并采用Hermite矩模型,通过其前4阶中心矩,将分布未知的响应过程转化为标准高斯随机过程,进一步结合泊松过程法给出了结构在强风作用下的抖振动力可靠性数值分析方法。最后以东海某大跨径悬索桥为工程背景,详细探讨了其加劲梁构件基于强度的抖振动力可靠度,结果表明加劲梁中支点截面为风振的最不利位置,其动力可靠度随风速的增大而降低,同时在高风速作用下,结构的非线性效应明显,仍采用传统的高斯过程假设会带来偏不安全的结果。
Because of the non-linear structure and the non-Gaussian distribution of fluctuating wind loads, the buffeting response of long-span suspension bridges under strong wind does not obey the assumption of Gaussian random process. Based on the time-frequency analysis of the buffeting response of the bridge, the response time of the structure is obtained by fully considering the influence of the wind load and the nonlinear factors of the structure. The Hermite moment model is adopted to calculate the distribution of the vibration response The unknown response process is transformed into a standard Gaussian random process, and a numerical analysis method of the vibrational reliability of the structure under strong winds is given in combination with the Poisson process method. Finally, with a large span suspension bridge in the East China Sea as the engineering background, the strength reliability of the vibration damper based on strength is discussed in detail. The results show that the fulcrum section of the stiffening beam is the most unfavorable position of wind vibration and its dynamic reliability varies with the wind speed While the nonlinear effect of the structure is obvious under the effect of high wind speed, the result of using the traditional Gaussian process will bring the unsafe result.