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对比了国内外高速列车车体设计标准中气动载荷的设计要求,分析了明线会车侧墙压力波,采用时间积分法,将车体瞬态压强转化为侧墙气动载荷,参照标准BS EN 12663-1—2010确定了包括气动载荷的车体疲劳载荷工况,以某型动车组头车为研究对象,建立了车体有限元模型,基于车体Goodman疲劳强度曲线编写了车体疲劳强度后处理程序,研究了车体疲劳特性。计算结果表明:在不考虑气动载荷时计算的较大应力幅值出现在底架上,而在考虑气动载荷时计算的车体较大应力幅值出现在侧墙门角和窗角上,最大应力幅值为33.63 MPa,疲劳强度安全系数为2.26,相对于侧墙,底架的应力幅值较小,小于10.00 MPa,疲劳强度安全系数大于10.00。在垂向载荷作用下,侧墙最大当量应力为68.17 MPa,叠加气动载荷后侧墙最大当量应力为85.31 MPa,应力增大了25.14%,因此,气动载荷对侧墙影响较大,容易导致侧墙发生疲劳失效。可见,在高速列车车体设计时,应将气动载荷与其他疲劳载荷相组合对车体疲劳强度进行评定。
Comparing the design requirements of aerodynamic loads in the design standards of high-speed trains at home and abroad, the pressure wave on the side walls of the line will be analyzed and the transient integral pressure is converted into the aerodynamic loads on the side walls using the time integral method. Reference standard BS EN 12663 -1-2010 The fatigue load of the vehicle body including the aerodynamic load is determined. Taking the first car of a certain EMU as the research object, the finite element model of the car body is established. After the fatigue strength curve of the Goodman body is written, Processing procedures, study the body fatigue characteristics. The calculation results show that the larger stress amplitude calculated when the aerodynamic load is not considered appears on the chassis, while the larger stress amplitude of the vehicle body calculated in considering the aerodynamic load appears on the side wall angle and the window angle, The stress amplitude is 33.63 MPa and the fatigue strength safety factor is 2.26. Compared with the side wall, the stress amplitude of the underframe is smaller, less than 10.00 MPa, and the fatigue strength safety factor is greater than 10.00. Under the vertical load, the maximum equivalent stress of the side wall is 68.17 MPa. The maximum equivalent stress of the side wall after superimposed aerodynamic loading is 85.31 MPa and the stress increases by 25.14%. Therefore, the aerodynamic load greatly affects the side wall, Wall fatigue failure. Visible, in the design of high-speed train body, pneumatic loads should be combined with other fatigue loads to assess the fatigue strength of the body.