Fatigue reliability analysis of running system of large passenger vehicle considering velocity distribution

Abstract

Based on the theory of nominal damage prediction, the influence of vehicle velocity on fatigue damage is analyzed, and the equivalent coefficient of different speed is proposed. The real vehicle test is carried out, and the equivalent coefficient of different velocity is calculated, and the fatigue reliability of running system is analyzed. Introduction Reliability is the basic guarantee for the safe operation of vehicles, and also the necessary condition for ensuring the transportation efficiency. From 1970s, the domestic and foreign scholars have carried out a lot of research on the fatigue life prediction of automobile and parts. In 2012, KUEH J J[1] analyzed the static fatigue of composite steel plate spring with the same size, and obtained the influence of the composition of the steel plate spring on the deflection and fatigue life; Kolokol’tsev V A[2] used the spectral analysis method based on statistical dynamics to calculate the strength and fatigue life of the vehicle support system under the condition of random vibration; Mironov V I[3] established a periodic degradation model of vehicle parts materials; In 2012, the corrosion fatigue of welded aluminum vehicle structure under constant amplitude and variable amplitude cyclic loading was studied by Sonsino C M[4]; In 2013, the fatigue of solder joints under the actual operating conditions was studied by Miki C[5]; In 2014, Zhao L H[6] estimated the fatigue life of vehicle rear axle considering the role of below the fatigue limit operation load on fatigue damage. In China, Yuanzhang Sun[7] put forward the evaluation index system of power system operation reliability in 2005; in 2011, Ding Feng[8]established the relationship between the tool vibration state information and the tool wear life; Baojia Chen[9]used the tool vibration signal accurately to estimate the reliability of the cutting tool. The large operating passenger vehicle has the characteristics of large capacity, long distance, and so on. Fatigue failure of driving system may burst under loading and road complex loading, which would cause fatal road traffic accidents [10]. Therefore, this paper mainly analyzes the influence of driving speed on the fatigue reliability of large operating passenger vehicle. Theory analysis Pseudo Damage In the practical reliability engineering practice, the stress, strain, acceleration, displacement, torque, force, etc. from the angle of energy, can be called the Taking the generalized stress as the input, using the rain flow counting method to calculate the load cycle number; according to the S-N curve and the Miner rule, the damage is called nominal damage or pseudo damage[11]. b S S N N / 1 0 0 ) / ( = . (1) Where N is the number of failure cycles, and 0 S is the fatigue limit, and S is the alternating stress, and b is the Basquin slope. 2nd International Conference on Machinery, Materials Engineering, Chemical Engineering and Biotechnology (MMECEB 2015) © 2016. The authors Published by Atlantis Press 637 Palmgren-Miner Linear cumulative damage rule Miner assumed that when the absorbing energy reaches limit, fatigue failure happens; the absorbing energy is proportional to number of cycles. W is absorbing energy limit value before the failure; N is the number of total cycles before the failure; When the number of cycles is 1 n , correspondingly the absorbing energy is 1 W , there are