
移动荷载作用下三塔悬索桥的强迫振动研究
The study of forced vibration for threetower suspension bridge under moving loads
Feng Zhaoxiang1、Chen Liang2、Miu Changqing2
针对泰州大桥开展结构动力特性计算,分析了不同移动速度以及不同移动荷载大小对于三塔两跨悬索桥结构动力响应的影响。结果表明,三塔两跨悬索桥的一阶竖弯振动基频约为0.08 Hz,远低于载重汽车的固有频率,不会形成共振条件。简单的移动荷载作用下三塔两跨连续支承悬索桥的内力、位移响应与同等静力荷载作用效果比较接近。移动荷载的质量越大、速度越大,结构的内力、位移响应就越大,并与车重呈近似正比例关系。结构内力、位移的荷载放大系数不随移动荷载质量的大小而改变。
Taking Taizhou Bridge for example, dynamic characteristics of the finite element model are analyzed and then the effects of different moving speeds and loads on dynamic response of three-tower twospan suspension bridge are studied. The result demonstrates that vertical bending of natural frequency is approximately 0.08 Hz, which is far below natural frequency loading truck, and will not form resonance condition. The response of force and displacement of three-tower twospan continuous suspension bridge under simply moving loads and equivalent static loads are the same. The structural will be greater when moving loads quantity and speed become greater and they have similar positive relationship. However, the load amplification factor of structural force and displacement does not vary with the quantity change of moving loads.
dynamic characteristics / forced vibration / response / load amplification factor
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