中南大学学报（自然科学版）2024，Vol.55Issue(4)：1644-1653,10.DOI:10.11817/j.issn.1672-7207.2024.04.032
机车车体枕梁关键含缺陷结构疲劳寿命评估
Fatigue life assessment of key defective structures of locomotive body sleeper beam
摘要
Abstract
In order to study the service safety of structures of sleeper beam with defects,firstly,the structural stiffness and deflection characteristics of the sleeper beam in bottom under different sizes were compared based on finite element simulation.According to the optimal structural test size,the equivalent fatigue bench test was carried out to obtain the stress distribution state and the potential crack position of the weld focus,and the consistency between the structure of sleeper beam and the simulation model was verified.Then,based on the structural integrity assessment method in BS 7910:2019 standard,the critical failure state of the structure was obtained by introducing the quantified crack defect,and the life prediction of the key weld area was realized.Combined with the numerical simulation method of fracture mechanics,the crack growth simulation of the local model structure was realized from the perspective of simulation,and the damage tolerance analysis of the structure with crack defects was completed.Finally,the reliability and difference of the results of the theoretical method based on standard evaluation and the numerical simulation method were compared and analyzed.The results show that the stress distribution of the submodel structure bench test of sleeper beam is consistent with that of the simulation model.The weak area of the submodel is concentrated in the fillet weld of the vertical shock absorber.Based on the BS 7910:2019 standard and numerical simulation calculations,the critical depths of the surface defects of the fillet weld of the shock absorber seat are 6.50 mm and 7.85 mm,respectively,and the corresponding fatigue load cycles are 1.029×105 and 1.121×105.The results of the two evaluations are in good agreement.关键词
机车车体/焊接结构缺陷/FAD图/疲劳寿命评估/应力强度因子Key words
locomotive body/welded structure defect/FAD diagram/fatigue life assessment/stress intensity factor分类
交通运输引用本文复制引用
范晓达,朱涛,张弛,王超,肖守讷,阳光武..机车车体枕梁关键含缺陷结构疲劳寿命评估[J].中南大学学报（自然科学版）,2024,55(4):1644-1653,10.基金项目
国家自然科学基金资助项目(52175123) （52175123）
四川省杰出青年基金资助项目(2022JDJQ0025) （2022JDJQ0025）
四川省国际科技创新合作项目(2022YFH0075)(Project(52175123)supported by the National Natural Science Foundation of China （2022YFH0075）
Project(2022JDJQ0025)supported by the Outstanding Youth Fund of Sichuan Province （2022JDJQ0025）
Project(2022YFH0075)supported by the International Science and Technology Innovation Cooperation of Sichuan Province) （2022YFH0075）
