考虑气动载荷的动车组铝合金司机室焊接接头应力因子分析

Stress Factor Analysis of Welded Joint in Aluminum Alloy High-Speed EMU Cab Considering Aerodynamic Fatigue Load

基于EN1999-1-3:2007和IIW-2008标准及EN15085-3标准,研究高速列车频繁地通过隧道时列车头部或尾部承受瞬间突变的气动载荷导致车体结构疲劳损伤的问题.基于上述标准的接头疲劳性能参数和疲劳评定方法及损伤等效原则,应用C#语言和ANSYS的APDL语言编写了高速动车组铝合金车体在BS EN12663标准的加速度疲劳载荷和气动疲劳载荷共同作用下,车体焊接接头应力因子的计算程序.在2×10^(6)次的0~4000 Pa气动载荷和107次的三方向加速度±0.15 g载荷共同作用下,利用某高速动车组头车车体结构有限元模型和自编计算程序对司机室焊接接头进行疲劳评估与应力因子分析.结果表明:主要由气动疲劳载荷引起的司机室焊接接头的累积损伤和应力因子均是IIW的计算结果大于EN 1999-1-3的计算结果;司机室立柱与边梁焊缝的累积损伤和应力因子最大,分别为0.753和0.987.建议高速动车组司机室焊接结构抗疲劳设计时应重点关注气动疲劳载荷.

Using EN1999-1-3:2007 and IIW-2008 and EN15085-3 standards,the fatigue damage caused by the sudden aerodynamic fatigue load on the head or tail of high-speed trains when they frequently pass through the tunnel was studied.Based on the fatigue performance parameters of the joints,fatigue assessment method and damage equivalence principle in the above standards,the welded joint stress factor calculation program of aluminum alloy high-speed EMU body under the combined action of acceleration fatigue load from BS EN12663 standard and aerodynamic fatigue load was written by using APDL language of ANSYS and C#language.Under the combined action of 2×10^(6) times of 0-4000 Pa aerodynamic fatigue load and 107 times of±0.15 g acceleration in three direction loads,the fatigue assessment and stress factor analysis of the welded joints in EMU cab were carried out by using the finite element model of a high-speed EMU body structure and the self-made calculation program.The results show that the cumulative damage and stress factor of the wel-ded joints of the EMU cab,which are mainly caused by aerodynamic fatigue loads,are the results of IIW cal-culations greater than those of EN 1999-1-3,and the cumulative damage and stress factors of the weld line between the pillar and the side beam in the cab are the largest,which are 0.753 and 0.987 respectively.It is recommended that the aerodynamic fatigue load should be paid more attention to in the anti-fatigue design of welded structure in the cab of the high-speed EMU.