Failure assessment of a leaf spring eye design under various load cases. (May 2016) - Kong, Y.S.
Abstract: This paper analyzes the capability of various leaf spring eye designs to prevent failure under braking, cornering, and pothole striking loading conditions. A leaf spring is a vital suspension component of heavy trucks, such that the failure of leaf spring eyes could cause fatal accidents. However, the current design of leaf spring support eyes is solely estimated based on the maximum vertical loads exerted on the leaf spring. The actual torsion or shear loads exerted by the ground to the leaf spring eye extremely high, but the experimental proving ground methods are too expensive to perform load analysis. In this analysis, the forces exerted on the spring eye are simulated under extreme load cases, such as braking, cornering, and pothole striking. The magnitudes of the different loadings were extracted from a multibody dynamics model and were used as the load inputs to the finite element explicit simulation. The principal surface stresses of four different spring eye designs were obtained and compared to the material yield and the ultimate tensile strengths to evaluate the sustainability of the spring eye during extreme load cases. Results show that a minimum thickness of 17 mm is sufficient for the leaf spring eye design to prevent failure under extreme torsional loadings. This research provides insightful analysis of leaf springs to prevent the occurrence of failure during engineering design. Highlights: Failure of a leaf spring eye will cause catastrophic vehicle accident. Traditional spring eye design did not take the extreme load case that may lead to failure into consideration. Spring eye was modelled using finite element method and multibody dynamics. Suitable spring eye design was proposed to prevent failure caused by extreme load cases. 17 mm spring eye design surpasses all the extreme load cases without failure.