Study On The Relationship Between Dynamic Stress Of Bogie Frame And Operation Condition

Bogie frame is one of the important components of vehicle,it not only has the function of support and transmission force,but also can guide the direction of vehicle operation,In the actual operation of t he vehicle,the frame bears a variety of complex alternating loads.Under the action of long-term alternating load,the fatigue damage of the frame will occur.When the damage reaches a critical value,the operation safety of the train will be seriously affected.Therefore,it is very important to study the safety of the architecture and the causes of the architecture damage.Based on dynamic stress test,this paper studied the stress state and damage of the frame under different line conditions,mainly including the following contents:1.This paper briefly introduces the structural characteristics and basic parameters of the bogie frame of model B car,and determines the layout scheme of the key fatigue positions and dynamic stress measuring points through the analysis of the stress condition and fatigue strength of the frame.The velocity signal,acceleration signal,gyroscope signal and strain signal were collected after long-term tracking test.n Code software is used for data processing of the collected signals,and the equivalent stress is calculated to complete the preparation of the stress spectrum.2.Identify and analyze the line conditions and operating conditions of the train based on the route diagram and the collected data.The working condition of the straight line,curve and switch is identified by the gyroscope signal,and the curve radius is calculated by software and compared with the actual circuit diagram.The speed signal is used to identify the acceleration,deceleration and uniform speed of the train,and the speed level is divided according to the operating speed.Rail wave wear is identified by axle box acceleration signal.3.Analyze and study dynamic stress characteristics in time domain and frequency domain respectively.The first is to calculate the stress amplitude of each key position,determine its stress situation and find out the position where the stress is large and easy to cause fatigue damage.The second is to find out the region where the acceleration of the axle box changes obviously,study its stress condition,and determine the influence of rail wave mill on the stress of the key parts.Finally,the dynamic stress of the frame is analyzed and studied from the perspective of frequency domain,and the energy source of the main frequency of the vibration at the key position of the frame is determined,and the main factors affecting the vibration of the frame are obtained.4.Through the study of different circuit conditions,the relationship between the circuit and the dynamic stress of the frame is determined.A large number of test data of the same working condition were summarized and analyzed,and the influence of different speed grades on dynamic stress was compared under the same line condition.Under the condition of the same speed level and the same line,different curve radii have influence on the dynamic stress.Under the same curve radius,the dynamic stress is affected by different velocities.The change of the stress on the train as it passes the switch.