轨下新型网孔式弹性垫板力学性能影响研究

为了提高轨道交通轨下弹性垫板的力学性能,使垫板材料的弹性充分发挥,研究一种新型网孔式轨下弹性垫板结构。通过建立网孔式轨下弹性垫板的有限元计算模型,选用Mooney-Rivlin超弹性本构模型模拟橡胶材料特性,在弹性垫板材料参数不变的条件下,通过网孔间距、网孔内接圆直径、板厚和倒角半径等关键参数来调整网孔式弹性垫板的静刚度,分析其对弹性垫板力学性能的影响,并与传统沟槽型弹性垫板进行对比。结果表明:在孔径不变的条件下,网孔间距增大,垫板静刚度近似线性增大,最大应力增大;网孔直径增大,垫板静刚度近似线性减小,最大应力减小。垫板厚度增大,静刚度明显减小,而最大应力小幅减小;网孔结构倒角后弹性垫板的静刚度小幅增加,但最大应力明显减小。相比于静刚度相近的沟槽型弹性垫板,网孔式弹性垫板的最大应力明显减小,可有效提高其耐久性,同时网孔式弹性垫板的静刚度具有可灵活调整的能力,因此,将网孔结构应用于轨下弹性垫板具有可行性。

Study on the Influence of Mechanical Properties of New Mesh-type Elastic Under-rail Pad

In order to improve the mechanical properties of elastic under-rail pad and fully release the elasticity of rubber material,this essay analyzes a new structural type of mesh-type elastic under-rail pad.By establishing a finite computing element mode of mesh-type elastic under-rail pad,this essay simulates the specific function of rubber material by means of Mooney-Rivlin hyper-plastic constitutive model.Furthermore,with the elastic pad material of same parameters,this essay tries to adjust the static stiffness of the mesh-type elastic pad based on mesh spacing,mesh inner circle diameter,thickness of elastic pad and chamfer radius,analyze it’s influence on the mechanical properties and compares it with traditional groove-type elastic pad.The results show that:under the condition of constant mesh aperture,when mesh spacing increases,the static stiffness of the pad tends to be approximate linear increase,and the maximum stress increases;when the mesh diameter increases,the static stiffness of the pad tends to be approximate linear reduction,and the maximum stress decreases.With the increase of the thickness of the elastic pad,the static stiffness decreases obviously,while the maximum stress decreases slightly;the static stiffness of the elastic pad slightly lowers after chamfering,but the maximum stress decreases obviously.Compared with groove-type elastic pad with similar static stiffness,the maximum stress of mesh-type elastic pad is significantly reduced,which can effectively improve the durability of elastic pad.At the same time,the static stiffness of mesh-type elastic pad can be flexibly adjusted.Therefore,it is feasible to apply mesh structure to elastic under-rail pad.