重载铁路用新型网孔式弹性垫板的力学特性研究

Study on Mechanical Properties of a New Mesh-Type Elastic Pad for Heavy-Haul Railway

重载铁路轨道系统的弹性垫板由于承受载荷较大,易出现疲劳破损现象。鉴于既有弹性垫板存在应力集中且阻尼较小的现象,提出一种新型网孔式弹性垫板,可改善应力分布,提升阻尼特性。为探究将网孔式弹性垫板应用于重载铁路扣件系统的可行性并验证相较于既有弹性垫板的优越性,分别建立适用于重载铁路弹条Ⅱ型扣件系统的既有弹性垫板和新型网孔式弹性垫板有限元模型。在同刚度条件下,对比研究网孔式、沟槽式、棱台式弹性垫板的竖向刚度、横向刚度和应力分布特征。研究结果表明,网孔式弹性垫板的应力应变分布更均匀,其最大应力相较于沟槽式弹性垫板和棱台式弹性垫板降低约30%,力学特性更好,且具有较好的竖向刚度保持性能;在施加横向载荷后,网孔式弹性垫板的横向刚度比棱台式弹性垫板的小,更接近于沟槽式弹性垫板;新型网孔式弹性垫板具有在重载铁路中推广应用的潜力。

Elastic pads used in heavy-haul railways are prone to fatigue failure due to the large loadbearing forces.To address issues of stress concentration and low damping capacity in existing pads,the study proposed a new mesh-type elastic pad designed to improve both stress distribution and damping characteristics.In order to explore the feasibility of applying the mesh-type elastic pad in heavy-haul railway fastening systems and to verify its superiority over traditional pads,finite element models for both the existing elastic pads and the new mesh-type elastic pad,designed for type II fastener system,were established.Under identical stiffness conditions,a comparative analysis was conducted on vertical stiffness,lateral stiffness,and stress distribution characteristics of mesh-type,grooved and prismatic elastic pads.The results showed that the mesh-type elastic pad exhibited a more uniform stress and strain distribution,with maximum stress reduced by about 30%compared to the grooved and prismatic elastic pads.This pad also demonstrated superior mechanical properties and vertical stiffness retention.Under lateral loading,the mesh-type pad showed lower lateral stiffness than the prismatic pad,more similar to the grooved pad.These findings suggest that the new mesh-type elastic pad holds great potential for widespread application in heavy-haul railways.