Fatigue Analysis About The Key Positions Of T20,000 Marshalling C80B Gondola Car

Density, carrying capability and speed of railway freight cars are the three essential factors to improve the railway transportation ability. At present, Datong and Qinhuangdao special railway lines for carrying coal will travel T30,000 heavy haul trains on the basis of traveling T20,000 heavy haul trains. Since we carried out high speed and heavy load, the C80B and other main vehicle carbody structures appeared fatigue crack damage successively, such as cracks of endwall, heart plate beam and jambs and so on. Consequently, the fatigue problems of vehicle structures become one of the key factors for restricting freight vehicle equipment technology promotion.Current structural strength design specifications and experimental standards of freight vehicle in our country is still imperfect, especially lacking these fatigue strength design specifications and experimental standards conforming to our actual utilization conditions. So, it's very urgent to update the fatigue strength design specifications of the freight vehicle structure. And it will have great significance for upgrading our country's design level of vehicle carbody structures.This paper takes the CB0B gondola car endwall of car body as the study object, having processed the load-time history data of measuring points of endwall and carried out the rainflow counting on the basis of the dynamic stress test of the T20,000 heavy haul trains, then compiled load spectrum of endwall according to rectangular distribution and triangle distribution respectively.On the basis of Solidworks 3-d software, a solid model of C80B carbody was set up. Afterwards, on the condition of center plate loading, longitudinal loading and endwall impacting, the carbody was calculated and got some positions with high stress. Based on calculation methods about fatigue damage of AAR standard and BS EN1993-1-9 Standard respectively, fatigue damage and cumulative damage of above mentioned positions were calculated referring to actual measured center plate load spectrum,longitudinal load spectrum in Datong and Qinhuangdao special railway lines as well as endwall load spectrum compiled. Finally, carried on every position damage statics and carried out fatigue life prediction of endwall in accordance with AAR standard and BS EN1993-1-3 standard separately. Damages about transposition of transverse and longitudinal welding seam between bearing beam of endwall and center sill and transverse welding seam between bearing beam and center sill are the biggest two positions through calculating and analysis, approximately 1.58e-02 and 2.13e-03 separately. Their fatigue life are 40,000 kilometer and 290,000 kilometer respectively.