Search

To study the reliability of automobile parts under the influence of abrasion， the biggest wear loss is taken into account in the gradual changing reliability model and the model of reliability state with the changing of time is obtained. Then， the secondary moment and the random perturbation method are adopted to give a quantitative analysis of the gradual changing reliability and the sensitivity. Finally， the effectiveness of the proposed method is confirmed by an example and the Monte Carlo. The fitting curves of the regularities of distribution of reliability and of sensitivity with abrasion are obtained， which can well reflect the change of reliability of dangerous sections of automobile parts in wear conditions and provide references for the gradual changing reliability with abrasion. [ABSTRACT FROM AUTHOR]

In view of the crack appearing at the first bracket on the left side of frame connected with vehicle body during field test, a fatigue analysis on the frame is conducted with CAE technique, showing the low analytical fatigue life of that bracket. Based on this, a procedure of auto-part structure optimization based on fatigue life is proposed. Accordingly topology optimization is adopted to determine the rational distribution of bracket material with consideration of fatigue life constraint, and then according to the results of topology optimization with both fatigue life and mass factors taken into account, a size optimization is performed on the bracket with connected frame. The results show that after optimization the fatigue life of frame is greatly increased, meeting the requirements of the manufacturer with the total mass kept basically unchanged. [ABSTRACT FROM AUTHOR]

For studying the effect of methanol gasoline on the corrosion and mechanical properties of rubber parts in vehicles, an immersion test of several currently used rubber parts in methanol gasoline is conducted to observe the variation relationship between the deformation and acting force of rubber parts and to analyze the cause of change of rubber parts after immersion. The results show that the black precipitate of solution, in which rubber parts are immersed, contains carbon black; the rubber tube made of NBR + CR or FKM + braided layer + ECO are rather significantly subjected to the effects of methanol concentration of methanol gasoline, leading to marked deterioration in mechanical performance; multi-layered PA12 is also greatly subjected to the effects of methanol but is not sensitive to the proportion of methanol added; while methanol has no apparent effects on the oil seals for intake and exhaust valves. [ABSTRACT FROM AUTHOR]