任意移动质量弹簧列作用下梁桥动力响应分析

Analysis of dynamic response of simply supported beam bridge subjected to successive moving mass-spring systems

将简支梁简化为Euler梁,基于振动理论推导建立了用于桥梁动力响应分析的任意移动质量弹簧列模型,并通过适当的参数选取将其退化成任意移动荷载列模型,使得两类经典模型合二为一。通过计算表明:在共振车速下,质量弹簧列模型条件下的桥梁响应较荷载列模型小;而在非共振车速下,两类模型条件下的桥梁响应差别不大。此外,对高铁简支梁应用分析可知:一定条件下在32m梁上行驶的车辆长度控制在19-23m范围内较合适;且该梁的共振车速约为156m/s、52m/s、39m/s,消振车速约为134m/s、78m/s、57m/s。这在实际应用时应予以注意。

Simply supported beam is modeled as Euler-Beam and according to the vibration theory,a vehicle-bridge model to analyze the dynamic responses of bridge subjected to the passage of successive moving mass-spring systems,or successive moving loads,with random intervals is established.Therefore,the two classical vehicle models are unified into one.The simulation results show that the dynamic responses of bridge under mass-spring systems are smaller than that under moving loads when the vehicle reaches its resonance speed,but they are almost the same when the vehicle doesn't reach its resonance speed.The dynamic performance of the simply supported beam bridge in high-speed railway is analyzed.It can be found that the length of the vehicle running on the 32m bridge should be held within a range from 19m to 23m under a certain condition.The resonance speed of the beam is about 156m/s,52m/s and 39m/s,while the cancellation speed is about 134m/s,78m/s and 57m/s.Attention should be paid to this in the practical application of the beam.