有砟轨道动力性能分析的频域方法

建立有砟轨道的三层连续弹性支承模型，推导了钢轨、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。

Prediction and Assessment of Traffic Noise for a Residential Quarter

With acceleration of urbanization, influence of traffic noise on urban acoustic environ- ment becomes larger and larger. Reduction of the impact of traffic noise on residential areas with some effective measures is the key point for urban acoustic environment protection. Prediction and assessment of the impact are of significance in practical applications. In this paper, a 3D simulation model for a residential quarter is built by using Cadna software. The effects of some traffic noise reduction schemes are predicted and evaluated. In comparison of these effects, more economical and effective schemes can be selected. The method and results given in this paper provides some data for traffic noise assessment and environment planning of residential quarters.