摘要
基于移动荷载列通过简支梁桥的解析模型,从理论上揭示出决定桥梁动力系数的关键参数。为满足运用模态叠加法对全桥各位置进行动力分析的精度要求,提出了必要模态数的概念,确立了所需桥梁模态数量的判定原则。以8节编组列车通过某20m跨度简支梁桥为例,分析了常用几种不同简化列车荷载模型对动力系数的影响,结果表明:动力系数定量分析时应采用可表征实际轮轴位置的移动荷载列模型。
The primary parameters that govern the dynamic factors of a simple-supported beam traversed by discrete moving loads are analytically identified.The concept of necessary mode amount is proposed to achieve the required accuracy for the dynamic responses of various locations on the beam.Thus the principle is established to determine the amount of modes of vibration required in the modal superposition based dynamic factor analysis.A train consists of eight vehicles is modeled as three types of common used discrete moving load models for comparison.The differences between dynamic factors obtained from the three simplified load models are evaluated regarding a simple beam with span length of 20m.It is found that the moving load model representing the actual locations of the axles of the train should be used for quantitative analysis of dynamic factors.
出处
《工程力学》
EI
CSCD
北大核心
2012年第10期177-183,204,共8页
Engineering Mechanics
基金
高等学校博士学科点专攻科研基金项目(20090072110044)
"十一五"国家科技支撑计划"高速磁浮交通技术创新及产业化研究"项目(11505JC094)
关键词
简支梁桥
动力系数
移动荷载列
模态叠加
轨道交通
simple-supported bridge
dynamic factor
discrete moving loads
modal superposition
rail transit
