عنوان مقاله [English]
This article presents a completed analysis for the material investigation, the mechanism, the vibration behavior, the stress and fatigue properties in valve springs. In the first stage, the failure analysis of a broken spring is performed based on material investigations. Then, by changing the spring design from one-step to two-step, a suggestion is proposed to improve the performance of the spring. In order to verify this suggestion, the spring mechanism is analyzed based on the velocity and the acceleration. In addition, stress and fatigue analyses are conducted.