Research On Fatigue Reliability Of ZK6Bogie’s Side Frame

With the rapid development of our national economy, the railway freight demand increased and the requirements of the truck were increasingly stringent.At present, China’s railway freight cars widely used three pieces bogies.The side frame as one of the components bogie plays an extremely important role.But the fatigue damage problem has become the main factor restricting the promotion of freight cars’ bogie frame technology.If the side frame appeared fatigue fracture in the opearation, which will be a serious threat to the safety of train opearation. The consequence wil be unbearable to contemplate.Thus research on the side frame fatigue problem has become apriority among priorities.Until now, researchs on the side frame fatigue problem are mainly through thesimulation loading test on bench indoor.Due to the serious lack of the measured data about the load spectrum of the side frame, bring about the analysis results deviate from the actual operation of China’s railway freight evidently.This paper based on a development project of the Ministry of ways, which named "Test on Universal Open Wagon C70about the Load Spectrum". According to the measured line date, we can get the time history datas of the side frame of the ZK6bogie. Then draws up the load spectrum which can represent the universal railway lines conditions in China.The fatigue reliability assessment of the side frame of the ZK6bogie has been completed based on the measured load spectrum by using the finite element analysis, and the main research content in this paper can be summarized as following aspects.(1) Line test. This thesis has studied the experimental method of spectra test of railway freight car. A test method about how to install force transducers, strain gages and acceleration transducers on open wagon C70has been put forward, which can be used to complete the data acquisition task in a harsh testing condition during a long distance.(2) Compilation and verification of fatigue load spectrum of the side frame. About two testing datas were collected and processed, including test on Beijing-Harbin and test on Beijing-Chengdu. After processed and analysised, we got the one-dimensional and two-dimensional load spectrum of the side frame, which could be crucial data for fatigue design of new type of side frame in China in future.(3) Finite element analysis of the side frame.The finite element model of the side frame of the ZK6bogie was established. The fatigue critical parts on the side frame were found through the finite element calculation under vertical, transverse and transverse rolling conditions. The load-stress transformation factor was got, which can transfer the load spectra into stress spectra.(4) Fatigue reliability analysis of the side frame.The fatigue damage value of the fatigue critical parts were calculated, based on AAR standard. The correction factor of load spectrum damage was achieved through the comparison between load spectrum damage and stress spectrum damage. So that a more accurate assessment of the fatigue life of the side frame directly by load spectrum was achieved.