参数激励下CFRP与钢索斜拉桥动力性能对比分析

摘要

为对比分析CFRP索和钢索斜拉桥参数振动性能,对全桥及拉索进行模态分析,考虑拉索初应力、垂度,运用瞬态动力学方法分析计算参数振动,对比两种拉索参数振动性能,并讨论多种因素(拉索张力、激励振幅、阻尼比)对参数振动的影响.结果表明,应用CFRP索后的斜拉桥,可能发生参数振动的拉索数量减少,参数振动振幅也会显著降低,但也可能产生主共振振幅变大的不良后果;当桥面激励振幅较大时,CFRP索参数振动性能明显优于钢索.%In order to compare performance of parametric vibration between cables of CFRP and steel, modal analysis of the whole bridge and cable is conducted.Considering the initial stress and sag, parametric vibration is analyzed using the transient dynamic method.The effects of various factors on parametric vibration are discussed, such as tension, excitation amplitude and damping ratio.The results show that for cable stayed bridge with CFRP cable the number of cables that parametric vibration may occur and the amplitude is significantly reduced.However, it is also possible to cause the undesirable outcome that the main resonance amplitude becomes larger.When the amplitude of excitation is big enough, CFRP cable has better performance than the steel cable under parameter vibration.