Study On Cracking Reasons And Optimizing Measures Of Side Window Glass Of Intercity EMU

With the rapid development of China's high-speed railway,the high-speed railway network in the central and western regions has been continuously completed and improved.However,the complex geological environment has brought great challenges to the operation of intercity EMUs.During the operation of the Xicheng Passenger Dedicated Line between December 2017 and January 2018,CRH3 A type intercity EMUs had many cracks in the side window glass of the driver's cab.In this paper,for the problem of the cracking of the side window glass of the CRH3 A intercity EMU running on the Xicheng Passenger Dedicated Line,it combines strength simulation analysis,installation strain test,aerodynamic load test,and dynamic stress test.The influence of installation technology,aerodynamic load,altitude and other factors on the cracking of the side window glass of the driver's cab was studied,and a rational solution was finally proposed.The specific research contents are as follows:(1)Static strength analysis of finite element model of driver's cab side window glass.Comprehensive analysis of the mechanical properties of CRH3 A EMU glass,curved tempered glass forming process,the structure of the side window of the driver's cab,and the occurrence of glass cracks.In order to ensure that the side window glass of the driver's cab meets the static strength requirements,it is based on the EN12663-2010 standard and aerodynamic load requirements.The loading and calculation of 8 kinds of static strength conditions for the overall structure of the driver's cab were performed to obtain the stress results of the various parts of the driver's cab,and the mechanical properties of the materials were evaluated.At the same time,according to the results of static strength analysis,the stress distribution of the glass under each load is preliminarily analyzed to determine the test scheme.(2)Deformation test and stress response analysis of glass during the installation of driver's cab side windows.By adopting the VIC-3D non-contact strain measurement system and digital image-related technology,digital measurement was performed on the situation where the stress distribution on the left and right side of the CRH3 A driver's cab was uneven during installation,resulting in uneven stress distribution.And stress changes.(3)Pneumatic load test of side window glass of EMU during line operation.A multi-channel dynamic signal test and analysis system,multi-channel internal and external pressure measurement and analysis software,and a patch pressure sensor are used to test the CRH3 A EMU on the Xi'an North-Hanzhong line in the Shaanxi section of the West Chengdu Passenger Dedicated Railway.The aerodynamic load data received by the left and right side window glass is collected and analyzed,so as to obtain the difference in air pressure inside and outside of each measurement point.(4)Dynamic stress test of side window glass of EMU during line operation.The statistical analysis of the relationship between the value of the dynamic stress generated by the side window glass of the driver's cab under the influence of external vibration loads and the time history during the actual operation of the train using the strain electrical measurement method is commonly used to obtain the individual measurement of the side window glass Distribution of dynamic stress loads at points.(5)After comprehensively considering the simulation data and experimental test results,the design of the installation process of the side window glass of the driver's cab is optimized to reduce the stress value of the side window glass and play a positive role in preventing side window cracks.