地铁弹条Ⅱ型分开式扣件力学特性研究

Research of Mechanics Characteristics of Elastic BarⅡ Separated Rail fastening

为完善优化地铁扣件的设计理论,针对弹条Ⅱ型分开式扣件的伤损特性,参考深圳地铁一期采用的WJ-3弹条Ⅱ型分开式扣件的结构形式,简化建立扣件系统静力学模型。基于有限单元法,计算分析弹性模量对扣压力的影响以及列车横向力、列车荷载作用下的垂向振动、压紧位移对弹条内部应力分布的影响。结果表明:压紧位移对弹条中的应力分布和最大应力的影响更为显著,当压紧位移超过10 mm时,弹条后肢弯位置可能折断。依据计算结果得出3种荷载下的弹条应力分布规律,同时从弹条强度出发,初步提出弹条的预压缩量和压紧位移限值,预压缩量不超过5 mm,压紧位移应小于9 mm。

In order to improve and optimize the theoretical design of the metro fastening, the fastening system model for static analysis is established according to the damage characteristics of elastic bar II separated rail fastening, with reference to the structure of WJ-3 elastic bar Ⅱseparated rail fastening used in the 1st phase of SHEN ZHEN metro. Based on the finite element method, the influence of elastic modulus on the clamping force is analyzed; analyzed are also the influence on the stress distribution of elastic bar caused by the transverse force of train, the vertical vibration under train load and the compression displacement. The research results show that the compression displacement has more obvious impact on the stress distribution and the maximum stress of clamping force. When the compression displacement is more than 10mm, the curved hindlimb of the elastic bar may be broken. The stress distribution of elastic bar under three different loads is obtained through calculation. From the viewpoint of the strength of elastic bar, the reference limits of precompressed elastic bar length and compression displacement are predicted. The length of precompressed elastic bar should be controlled not more than 5 mm and the compression displacement less than 9mm.