Research On Cycle Load Experiment Of High-speed Train Side Windows

As the high-intergration of modern technology, High-speed railway improvesquickly during the21stcentury. The speed of Chinese railway widely increased from2007, and China is going into the time of high-speed railway. While, as theincreasing of the train speed, the safety problem brought by the crossing air pressurewhich produced by two meeting trains or a train passing a tunnel has becoming moreprominent. As a momentary attack wave, the attack influence on side windowsproduced by crossing air pressure is more visibly, and may endanger the body safetyof the passengers at emergency. Simultaneously, long-term attack by the air pressurewould claim higher requirements of the fatigue property of the window system. So,evaluate the circle load bearing capacity of the side window, analysis the capacityaffecting factors, predicte fatigue life of the side windows, would make sense onboth the structural optimization of the windows being used and structural design of anew type window. Based on this, this paper focuses on the cycle load bearingcapacity of the train side windows; evaluate the bearing capacity of the windows,and do some experiments on the fatigue performance of the window system, thework completed are as follows:(1) Through measure the stress and deflection of the insulating glass of differentstructures under cycle load, the affect of the inside plate and outside plate thicknessratio and the air layer thickness on the bearing capacity of the insulating glass wereanalyzed. The results showed that: the thickness ratio will significantly change theload distribution between the inner and outer plate, and significantly affect thebearing capacity of the glass. The air layer thickness has little effect on the loaddistribution and load bearing performance of the insulating glass, but taking intoaccount other factors when used, the air layer thickness should not be too large ortoo small.(2) Through the experiment of the cycle load on Maglev train windows and CRH train windows, the stress and deflection distribution of the window wereanalyzed; by changing the amplitude and the frequency of the load, the influence ofthe load form was anaylzed. The results show that: the stress and deflection in theglass center are the largest. While, as the load amplitude increasing, stress of thecorner and long edge center increase rapidly, even over the center location. Due tothe different constraints ways, the stress on different directions is different. thetensile stress is larger than compressive stress, the different constraint ways betweenthe outer and inner plate are the main reason leading to the deflection and the loadbearing ratio of the outer plate different on opposite directions. With the loadincreases, the impact of the frequency on the load distribution gradually weakened.The load proportion between the inside and outside films of hollow glass tends to aconstant number. Improve the peripheral side constraints will lead the loaddistribution to be stable.(3) For the fatigue problem brought by the crossing air pressure, fatigue loadexperiment of the side windows was carried out, the inflence of surface scratch onthe glass was studied, the fatigue life of the glass was predicted and assessmented.The results showed that: scratch depth is the most important factor of the glassfatigue life. The fatigue life of the experiment windows under load of±6000Pa isfrom107to108cycles, which means that except human damage, the damagepossibility of the glass during using life is small. But once the scratch reaches thecritical depth, the glass will break as soon as the load put on. In addition, the fatigueload has less affect on the performance of the windows, after impact million cyclesof±4500Pa load, the stiffness, the airtightness, the dew point keep well.(4)The fatigue properties of fastenings including the glue, the aluminum alloyfittings, and so on were studied. The results showed that: when thickness of the glassis small, the glue and the aluminum alloy fittings can easily lead to damage, at thistime, the strength of these fastenings become the weakness of the window; thestructural design of joints and the constraints strength of the window are the mostimportant factors of the window fatigue life.