【摘要】 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。更多还原

【Abstract】 The long-span suspension bridge’s buffeting responses are not Gaussian random processes because of the structural nonlinearity and non-Gaussian distribution of fluctuating wind load.Based on the accurate bridge buffeting response analysis of time history,considering the nonlinearity factors of structure and wind load,the structure’s non-Gaussian response processes are derived.The Hermite moment model is introduced to transfer the unknown distribution responses into the standard Gaussian random process based on their first four moments,and the numerical analysis method of structure’s dynamic reliability under strong wind action is then put forward combining with the Poisson process method.A long-span suspension bridge at the East Sea of China is analyzed,the buffeting dynamic reliability of stiffening girder is discussed in detail.The results indicate that(1) the middle support section of the stiffening girder is the critical section under fluctuating wind action,its dynamic reliability decreases with the wind speed increases;(2) the structure’s nonlinear effect is obvious under strong wind action,the traditional method of Gaussian process assumption will bring insecure results.更多还原