【摘要】 建立有砟轨道的三层连续弹性支承模型,推导钢轨、轨枕和道床的运动方程,并在频域内求得简谐激励下的稳态响应。再引入轮轨相互作用频域模型,并借助动柔度法计算轮轨力。在此基础上,采用MATLAB平台自编程序,实现轨道不平顺激励下的频域分析。在案例分析中,综合考虑轮轨力、力传递率、轨道各部件的振动等指标,对弹性扣件、枕下弹性垫板、复合轨枕、道砟垫以及它们的组合等多种减振措施进行对比。结果表明:减振措施使得系统的固有频率发生改变,进而导致各指标在不同频率范围出现复杂的变化规律;相比于弹性扣件,枕下弹性垫板和道砟垫表现出更好的综合效果,而复合轨枕的减振效果有限。更多还原

【Abstract】 A triple-layer continuously supported ballasted track model is built, and the kinematic equations of the rail,sleeper and ballast are derived. The steady-state responses of the model under harmonic excitation are obtained in the frequency domain. Then, the wheel/rail interaction model in the frequency domain is introduced, and the wheel/rail force is solved based on the dynamic flexibility method. The dynamic performance of the ballasted track induced by track irregularities is solved in frequency domain based on MATLAB programming. In the case study, the indexes of wheel/rail force, force transmissibility, track components vibrations are employed to assess the effects of vibration reduction measures such as adding elastic fasteners, laying soft baseplate under the sleepers, using composite sleepers, ballast mats and their combinations. Results show that the vibration reduction measures can change the ballasted track’s natural frequency and cause the complex variation of these indexes in different frequency ranges. Compared to the measure of adding elastic fasteners, the soft baseplate under the sleepers and the ballast mats have a better comprehensive effect, while the composite sleepers have limited vibration reduction effect.更多还原