客货共线砂浆离缝高度对轨道结构的动力影响

客货共线条件下CRTS I型板式无砟轨道CA砂浆与轨道板普遍存在离缝，为了得到CA砂浆离缝高度对轨道结构动力响应的影响规律，基于车辆-轨道耦合动力学以及子结构模态叠加法，将ANSYS计算的轨道部件子结构的自振特性输入SIMPACK，使用力元连接轨道各部件形成轨道系统，通过轮轨接触面及柔性钢轨节点间的位移和力的数据传递，实现列车和轨道子系统的耦合，建立了含CA砂浆离缝的CRTS I型板式无砟轨道的垂向耦合模型，研究了客货混运条件下CA砂浆离缝高度对轨道结构动力响应的影响. 研究表明:随CA砂浆离缝高度增大，钢轨动态位移、轨道板振动响应及CA砂浆动应力均显著提高；当CRH380通过，板端离缝高度为1.0 mm和2.0 mm时，钢轨位移分别增大了0.24 mm和0.27 mm，轨道板在25 Hz处振级分别增大了21.0 dB和21.7 dB，离缝根部砂浆最大动应力均达到0.2 MPa，离缝高度超过1.0 mm后，离缝高度对轨道结构动力响应的影响趋于平缓；当SS7E通过，板端离缝高度为1.0 mm和2.0 mm时，钢轨位移分别增大了0.48 mm和0.66 mm，轨道板在8 Hz处振级分别增大了15.5 dB和19.4 dB，离缝根部砂浆动应力分别达到0.24 MPa和0.36 MPa，离缝高度超过1.0 mm后，离缝高度对轨道结构动力响应的影响仍有较大的增长. 

Dynamic Influence of Gap Height of CA Mortar on Track Structure Under Mixed Traffic Conditions

For CRTS I prefabricated slab tracks used in mixed passenger-freight railway, the gap between the CA mortar and the track slab is a common disease. In order to analyse the influence of the gap height of CA mortar on the dynamic response of the track structure, a vertical coupling model of CRTS I slab track with gaps between CA mortar and track slab is established based on the vehicle-track coupling dynamics and the substructure modal superposition method. Firstly, the self-vibration characteristics data of the track component sub-structure, which was calculated by ANSYS, was inputted into SIMPACK, and the track components were connected through a force element to form the track system. Then, the train and rail subsystems were coupled via data transmission of the displacement and force between the nodes of the wheel-rail contact surface and flexible rail. The results show that with the increase in gap height, there is a significant increase in the dynamic displacement of the rail, vibration response of the track slab, and the dynamic stress of the CA mortar. For CRH380, when the gap height was increased to 1.0 mm and 2.0 mm, the rail displacement increased by 0.24 mm and 0.27 mm, respectively. At the same time, the vibration levels of the slab increased by 21.0 dB and 21.7 dB at a frequency of 25 Hz, and the maximum dynamic stress of the CA mortar at both ends of the gap reached 0.2 MPa. Thus, when the height of the gap exceeds 1.0 mm, the influence of the gap on the dynamic response of the track structure tends to be gentle. However, for SS7E, when the gap height was increased to 1.0 mm and 2.0 mm, the displacement of the rail increased by 0.48 mm and 0.66 mm, respectively. Simultaneously, the vibration level of the slab increased by 15.5 dB and 19.4 dB at a frequency of 8 Hz, and the maximum dynamic stress of the CA mortar at the ends of the gap reached 0.24 MPa and 0.36 MPa, respectively. Thus, when the height of the gap exceeds 1.0 mm, there is still a considerable increase in the influence of the gap on the dynamic response of the track structure.