IJESR Volume 3, Issue 12 ISSN: 2347-6532 __________________________________________________________ A Monthly Double-Blind Peer Reviewed Refereed Open Access International e-Journal - Included in the International Serial Directories Indexed & Listed at: Ulrich's Periodicals Directory ©, U.S.A., Open J-Gage as well as in Cabell’s Directories of Publishing Opportunities, U.S.A. International Journal of Engineering & Scientific Research http://www.ijmra.us 46 December 2015 ANALYSIS OF EFFECTS OF VEHICLE SUSPENSION SYSTEM STIFFNESS AND DAMPING ON OSCILLATORY COMFORT Jasmin Sehovic, B.Sc. 1 Boran Pikula, Ph.D. 2 ABSTRACT Primarily due to road irregularities, vehicle movement is invariably accompanied by oscillations of vehicle masses that cause tiredness and fatigue of passengers on one hand, and additional road and vehicle loads on the other hand. Oscillations of vehicle masses can cause changes in dynamic reactions of the road, which could furthermore decreasethe traction or brake forces, and jeopardize stability of movement. These negative consequences of oscillations are reduced by applying different designs of vehicle suspension systems. The study of complex mechanism oscillations with a large number of degrees of freedoms is generally performed on a simplified model. The selected model should include only the most important parameters and the parameters that are of a less importance should be ignored. By doing this, the analytical processing of the problem is accelerated and the practical verification of the results is simplified. Additionally, costs and time needed for the experimental testing are reduced. In this paper, an analysis of travel of sprung and unsprung vehicle masses was conducted, in dependence on vehicle suspension stiffness and damping, along with the speed of oscillation settling in dependence on vehicle suspension damping.Also, the analysis of vehicle oscillatory behavior on passengers' comfort and stability of movement on the road is presented. The model and results shown in this paper are an adequate basis for the next step, which is designing active suspension system ofthe vehicle. Key words:Oscillations, Stiffness, Damping, Comfort, Stability 1 Ph.D candidate, Faculty of Mechanical Engineering Sarajevo, University of Sarajevo, Bosnia and Herzegovina 2 Associate Professor, Faculty of Mechanical Engineering Sarajevo, University of Sarajevo, Bosnia and Herzegovina