铺设阻尼钢轨是从声源处对钢轨振动噪声进行控制的有效方法。本文将有限元法与边界元法相结合,建立阻尼钢轨-无砟轨道系统振动-声辐射分析模型,以高速轮轨力谱作为激励,分析阻尼钢轨材料、结构参数对钢轨导纳传递特性及声辐射特性的影响。计算结果表明:阻尼钢轨的减振降噪能力随阻尼材料损耗因子的增加而增强,但两者并非呈线性关系;增大阻尼层厚度可提高阻尼钢轨的耗能能力;约束板的材料特性及厚度对阻尼钢轨的减振降噪效果影响不大,约束板的设计宜采用轻质、较薄合金材料;将阻尼敷设在轨腰及钢轨上、下翼缘可取得最佳减振降噪效果,但在减振降噪要求较低的区段可将阻尼材料仅敷设在轨腰和钢轨下翼缘。计算及分析结果可为高速铁路阻尼钢轨的优化设计提供参考。
Using the constrained damping rail is an active control method for mitigating railway vibration and noise at the source.Based on the hybrid FEM-BEM method,a vibro-acoustic radiation model for damping railballastless track system was established.With high-speed wheel/rail force spectrum as external stimulus for the vibro-acoustic radiation model,the influence of materials and structural parameters of damping rail on rail admittance and acoustic radiated power was analyzed.The results show that the vibration and noise reduction properties of damping rail are enhanced with the increase of the loss factor of damping material.However,the relationship between them is nonlinear.Increasing the thickness of damping layer can improve the energy dissipation of damping rail.Lighter weight and thinner alloy materials can be used on the constrained layer as the material properties and thickness of constrained layer have little influence on the performance of damping rail.Best noise and vibration reduction effects can be achieved by laying damping material on rail top flange,rail waist and rail bottom flange.But in sections where the requirement of vibration and noise reduction is lower,it is also appropriate to lay the damping material only on rail waist and rail bottom flange.The calculation and analysis results can provide certain reference for the optimal design of the damping rail for high-speed railway.