Effect of Leaf Spring Curvature and Shape on Its Static and Dynamic Performance

Abstract

Transportation luxurious conditions haven't been known before the appearance of spring and damper as cooperative parts within the suspension systems. Spring shapes take a lot of forms depending on their duties and the working conditions as well as the available space. Due to its capability to absorb large amount of shock, beam bending mechanism has been adopted in cargo vehicle suspension systems. This work proposes circular base plate shape simply supported laminated leaf springs distributed according to set of suggested curvatures (circular, second order parabola and exponential) as geometrical modifications to increase the load carrying capacity by minimizing the induced maximum bending stress, enhancing the fatigue life or the dynamic safety factor and investigate their effects on the vibration characteristics. The proposed curvatures have been adopted to be alternative leaf springs instead of classical trapezoidal shape  circular curvature and represented mathematically in polar coordinate and feed to be numerically simulated and solved using Ansys Workbench software ver. 15. The most important results of this work is that the proposed circular shape leaf spring base plate reduces the maximum static bending stress by about 36% regardless its type of curvature and the dynamic safety factor under completely reversed load has been improved by about 300% by using the exponential curvature instead of the classical circular curvature.