Keywords— engine, heat transfer, pressure, temperature field of the piston. Abstract— Computer aided engineering (CAE) tools allow engineers to design product and to simulate these designs for residual stress, structural response, thermal effects, pre-processing and post processing fatigue on the automotive component. The main purpose of the preliminary analyses presented in the paper was to compare the behavior of the combustion engine piston made of aluminum alloys. The paper describes the mesh optimization with using finite element analysis technique to predict the higher stress and critical region on the component. As initial condition we considered a temperature on the head piston of 330 ° C and a total pressure of 5 MPa. There were studied two cases, a piston head and a piston, pin and connecting rod. I. INTRODUCTION AE analysis tools offer the tremendous advantage of enabling designers to consider virtually any molding option without incurring the expensive actual manufacturing of the machine component and machine time associated to make machine component. The ability to try new designs or concepts on the computer gives the opportunity to eliminate problems before beginning production. Additionally, designers can quickly and easily determine the sensitivity of specific molding parameters on the quality and production of the final part. The complex parts can be simulated easily by CAE tool [1,2,3,4]. Among engine components exposed to thermal effects, the piston is considered to be one of the most severely stressed, where a high amount of the heat transferred to a coolant fluid M.X. Calbureanu, is with the University of Craiova, Faculty of Mechanics, Department of Applied Mechanic and Civil Construction, Calea Bucuresti, 107, Zipe code 200512, Craiova, Dolj (corresponding author to provide phone: 0722634340; e-mail: madalina.calbureanu@gmail.com). R. Malciu, is with the University of Craiova, Faculty of Mechanics, Department of Applied Mechanic and Civil Construction, Calea Bucuresti, 107, Zipe code 200512, Craiova, Dolj (e-mail: ralucamalciu@yahoo.com). D. Tutunea is with the University of Craiova, Faculty of Mechanics, Department of Vehicles, Transportation and Industrial Engineering, Calea Bucuresti, 107, Zipe code 200512, Craiova, Dolj (e-mail: dragostutunea@yahoo.com). A. Ionescu, is with the University of Craiova, Faculty of Mechanics, Department of Applied Mechanic and Civil Construction, Calea Bucuresti, 107, Zipe code 200512, Craiova, Dolj (e-mail: adita_i@yahoo.com). M. Lungu is with the University of Craiova, Faculty of Electrical Engineering Electric, Department of Energetic and Aerospatiale Engineering (e-mail: mlungu@elth.ucv.ro). goes through it, this amount depends on the thermal conductivity of the materials employed, the average speed and the geometry of the piston and rings [5]. A piston is a component of reciprocating IC-engines. It is the moving component that is contained by a cylinder and is made gas- tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. As an important part in an engine, piston endures the cyclic gas pressure and the inertial forces at work, and this working condition may cause the fatigue damage of piston, such as piston side wear, piston head/crown cracks and so on. The investigations indicate that the greatest stress appears on the upper end of the piston and stress concentration is one of the mainly reason for fatigue failure. On the other hand piston overheating-seizure can only occur when something burns or scrapes away the oil film that exists between the piston and the cylinder wall [6]. In recent years, more and more efforts are made to increase horse power to weight ratio of internal combustion engines. In order to achieve the increased power to weight ratio, the necessity of design optimization of various internal combustion engine components is felt very seriously. Lighter piston reduces the dynamic balancing problem to a greater extent. So it is necessary to optimize the design of the piston to keep its weight minimum. This necessitates complete stress analysis of the piston. Analysis will help to modify the existing design for reducing the weight [7]. This paper presents the methodology for a spark ignition piston structural analysis using the finite element method. The loads from the tightening bolts process, the combustion peak pressure and thermal loading were considered as boundary conditions. It is important to determine the piston temperature distribution in order to control the thermal stresses and deformations within acceptable levels. The temperature distribution [8] enables the designer to optimize the thermal aspects of the piston design at lower cost, before the first prototype is built. Most of the internal combustion (IC) engine pistons are made of aluminium alloy which has a thermal expansion coefficient 80% higher than the cylinder made of cast iron. Therefore, the analysis of the piston thermal behaviour is extremely crucial in designing more efficient engines. The thermal analysis of such a piston is important from different point of views. First, the highest temperature of any point on piston [9] should not exceed 66% of the melting The finite element analysis of the thermal stress distribution of a piston head M.X. Calbureanu, R. Malciu, D. Tutunea, A. Ionescu and M. Lungu C INTERNATIONAL JOURNAL OF MECHANICS Issue 4, Volume 7, 2013 467