International OPEN ACCESS Journal Of Modern Engineering Research (IJMER) | IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 4 | Iss. 12 | Dec. 2014 | 40 | Optimization of Multi Leaf Spring by using Design of Experiments & Simulated Annealing Algorithm Narendra Yadav 1 , Prof. S. A. K. Jilani 2 1 (M E Scholar, RCET, Bhilai-India) 2 (Associate Professor, Department of Mechanical Engineering, RCET, Bhilai-India) I. Introduction A multi leaf spring is a curved shaped laminated plate with eye at both ends, generally used for the suspension in heavy vehicle. It is the oldest forms of springing techniques used. It’s slender arc-shaped with uniform rectangular cross section throughout the length. The rear and front axle is mounted on the center of the arc, while the eye end is used for attaching to the chassis. The basic problem which is encountered in MLS is the change in the dimensions of camber and leaf span due to frequent loading and continuous running of the tractor trolley. The basic observation carried out in this thesis is regarding the increase in the camber and decrease in the leaf span after a period of time. This acts as a limitation to spring action. Hence it becomes very essential to restore the spring action to the initial level. This is because the spring is always loaded and the load on it may be due to the trolley or due to its own weight. It is observed that due to the change in dimensions of camber and leaf span there is a decrease in the amount of comfort level both to the rider and the cargo loaded on it. The objective initially is to study the behavior of a MLS under static loading conditions by varying the camber and leaf span. II. Multi Leaf Spring Dimension and Boundary Condition The major difficulty in this work was that the rectangular cross section of the leaf spring was sweeped along the semi elliptical path. This tends to not assembled easily. So it needs to have proper attention and accuracy during the process of assembly. Hence in order to assemble in a proper manner it was very essential for us to use absolute dimensions of the each leave of MLS. The modeling and assembly of MLS has been carried out in CATIA V R20, the dimension of MLS has been maintain according to the manual measurement taken from the existing model of MLS.the dimension of MLS is as: Leaf Span = 900 mm, Camber = 120, Thickness = 10 mm and width = 60 mm There are two full length leaves, and seven graduated leaves used for the complete assembly of MLS. ABSTRACT: This work carried out on a multi leaf spring of a tractor trolley with maximum load carrying capacity of 5 Tones. The CAD model of this MLS has been modeled in CATIA V5. After successfully preparing the CAD model, MLS is then tested in Static Structural Analysis workbench for stress and deflection computations. The finite element analysis of the leaf spring has been performed by converting the model into number of nodes and elements and then applying the relevant boundary conditions under the static loading conditions. After implementation of FEA it was observed that the red area close to shackle was undergoing maximum value of stress. This observation leads us to the workbench of Knowledge ware and this aided us in studying the response of crucial output parameters of MLS in the form of Stress and Deflection via Design of experiments. DOE paved the way for SAA where optimization was carried out in order to reach the minimal stress. The corresponding values of camber and leaf span were recorded for minimal stress. Keywords: Computer Aided Design (CAD), Camber, Design of Experiments (DOE), Eye Distance, Finite Element Analysis (FEA), Multi Leaf Spring (MLS), (Simulated annealing algorithm (SAA).