【摘要】 研究目的:为研究不同类型梁单元对列车-轨道-简支梁耦合系统动力响应的影响,以12车编组高速列车通过6跨简支梁为例,基于多刚体动力学建立车辆垂向动力学模型,分别采用Euler-Bernoulli梁、Timoshenko梁及Mindlin板单元建立简支梁桥有限元模型,并开展基于三种不同类型梁单元简支梁模型的列车-轨道-桥梁耦合系统动力响应分析。研究结论:(1)在相同参数条件下,三种简支梁模型的自振频率各不相同,其中Euler-Bernoulli梁模型计算得到的简支梁自振频率最高,对应的理论共振车速也最大;(2)运营车速条件下,桥梁加速度响应受梁单元类型的影响显著,基于Euler-Bernoulli梁的简支梁振动加速度最小,基于Timoshenko梁的简支梁振动加速度与基于板单元的箱梁底板中点处的计算结果较为接近,而基于板单元的简支梁由于顶板局部受高频列车荷载激励的影响,因此顶板中点处的加速度最大;三种简支梁模型计算的首、末节车体加速度吻合良好;(3)共振车速条件下,Euler-Bernoulli梁模型和Timoshenko梁模型计算的桥梁加速度和位移吻合较好,但整体上大于板单元模型箱梁腹板及底板的计算结果,且Euler-Bernoulli梁模型和Timoshenko梁模型计算的末节车体加速度在振动形态上与板单元模型计算结果存在较大差异;同时,末节车辆由于受桥梁共振效应的影响显著,其车体加速度明显大于首节车辆;(4)本研究成果可为列车-轨道-桥梁耦合振动研究中桥梁数值模型的选择提供参考。更多还原

【Abstract】 Research purposes: Based on train-track-bridge coupling dynamics,the effects of three types of simply supported beams modeled as a Euler-Bernoulli beam,Timoshenko beam and shell-element system,respectively,on the dynamic responses of the coupled train-track-bridge system are studied. Then,taking a six-span simply supported bridge passed through by a high-speed train composed of 12 cars for the case study,the comparisons of dynamic responses of three types of coupled train-track-bridge system are undertaken.Research conclusions:( 1) The natural frequencies of the three types of simply supported beam models with the same section and material parameters are different. The Euler-Bernoulli beam has the highest natural frequency,as well as the resonant speed.( 2) At the operating speed,the acceleration response of the simply supported beam is affected significantly by the type of element,and the Euler-Bernoulli beam has the smallest bridge acceleration. The vibration acceleration of the Timoshenko beam is close to the calculation result at the midpoint of the bottom plate of the box girder of the shell-element system. The top deck of the box girder of the shell-element system,which subjects to the local high-frequency excitation,has the highest acceleration. The acceleration of the first and last vehicle body of the three types of models coincides well.( 3) At the resonant speed,the acceleration and displacement of bridge obtained by the Euler-Bernoulli beam and the Timoshenko beam are in excellent agreement,but on the whole,they are larger than that of the shell-element system. The Euler-Bernoulli beam model is quite different from the Timoshenko beam model at the acceleration of the last vehicle body. The dynamic response of the last car is considerably larger than that of the first car due to the passage of the serial beams in resonance.( 4) The research results can provide reference for the selection of bridge numerical model in the study of train-track-bridge coupling vibration.更多还原