Thesis (M.Eng.)--Chulalongkorn University, 2010

A simulation-based leaf spring model was created to study the effect of leaf spring suspension parameters on vehicle ride comfort. The main objective is to build a simulation model for ride comfort prediction from leaf spring parameters which can be used in design process. In this research, an experimental leaf spring model was verified by using a leaf spring test rig that can measure vertical static deflection of leaf spring under static loading condition. The verified model was then used to study the effect of leaf spring parameters on ride comfort of a light truck, using a simple 2–degree–of–freedom quarter–car model. In simulation, some design parameters of leaf spring, including the effect from shackle was applied, and the relationship between ride comfort performance (ISO2631–1) and variations in leaf spring design parameters were obtained upon different types of synthetic road irregularity profiles at constant velocity. The overall results show that ride comfort is better on smooth road with gradual changes from “very good” to “poor” road and sudden increase for “very poor” road. The values obtained from the proposed leaf spring model are different from those of the linear leaf spring model’s. Hence, it can be concluded that the proposed leaf spring model has significant effects on vehicle ride comfort.