Ali Belhocine et al./ Elixir Mech. Engg. 55A (2013) 13244-13250 13244 Introduction The braking process is in fact the matter of energy balance. The aim of braking system is to transform mechanical energy of moving vehicle into the some other form, which results by decreasing of the vehicle speed. The kinetic energy is transformed into the thermal energy, by using the dry friction effects and, after that, dissipated into the surroundings [1]. Have developed for a few decades at intervals raised in many sectors :nuclear power, space, aeronautics, automotive, petro chemistry, etc [1]. In 2002, Nakatsuji et. al. [2] did a study on the initiation of hair-like cracks which formed around small holes in the flange of one-piece discs during overloading conditions. The study showed that thermally induced cyclic stress strongly affects the crack initiation in the brake discs. In order to show the crack initiation mechanism, the temperature distribution at the flange had to be measured. Using the finite element method, the temperature distribution under overloading was analyzed. 3D unsteady heat transfer analyses were conducted using ANSYS. A 1/8 of the one piece disc was divided into finite elements, and the model had a half thickness due to symmetry in the thickness direction. In 2000, Valvano & Lee [3] did a study of the technique to determine the thermal distortion of a brake rotor. The severe thermal distortion of a brake rotor can affect important brake system characteristics such as the system response and brake judder propensity. As such, the accurate prediction of thermal distortions can help in the designing of a brake disc. In 1997, Hudson & Ruhl [4] did a study of the air flow through the passage of a Chrysler LH platform ventilated brake rotor. Modifications to the production rotor’s vent inlet geometry were prototyped and measured in addition to the production rotor. Vent passage air flow was compared to existing correlations. With the aid of Chrysler Corporation, investigation of ventilated brake rotor vane air flow was undertaken. The goal was to measure current vane air flow and to improve this vane flow to increase brake disc cooling. Temperature increases can strongly influence the properties of the surface of materials in slip, support physicochemical and microstructural transformations and modify the rheology of the interface elements present in the contact [ 5 ]. Recent numerical models, presented to deal with rolling processes [6,7] have shown that the thermal gradients can attain important levels which depend on the heat dissipated by friction, the rolling speed and the heat convection coefficient .Many other works [8- 9] dealt with the evaluation of temperature in solids subjected to frictional heating. The temperature distribution due to friction process necessitates a good knowledge of the contact parameters. In fact, the interface is always imperfect – due to the roughness – from a mechanical and thermal point of view. Recent theoretical and experimental works [10-11] have been developed to characterize the thermal parameters which govern the heat transfer at the vicinity of a sliding interface. In certain industrial applications, the solids are provided with a surface coating. A recent study has been carried out to analyze the effect of surface coating on the thermal behavior of a solid subjected to the friction process [12]. Increased thermal efficiency and the integrity of materials in high-temperature environments is an essential requirement in modem engineering structures in, automotive, aerospace, nuclear, offshore, environmental and other industries. Nowadays, the finite element method is used regularly to obtain numerical solutions for heat transfer problems. The most common choice when using finite elements is a standard Galerkin formulation [13] In this work, we will make a modeling of the thermomechanical behavior of the dry contact between the disc of brake pads at the time of braking phase, the strategy of calculation is base on the software Ansys 11 [14]. This last is elaborate mainly for the resolution of the complex physical problems. The numerical simulation of the coupled transient thermal field and stress field is carried out by sequentially thermal-structurally coupled method based on Ansys. Tele: E-mail addresses: al.belhocine@yahoo.fr © 2013 Elixir All rights reserved Thermal- mechanical coupled analysis of a brake disc rotor Ali Belhocine and Mostefa Bouchetara Faculty of Mechanical Engineering, University of Sciences and the Technology of Oran, L.P 1505 El -MNAOUER, USTO 31000 ORAN (Algeria) ABSTRACT The main purpose of this study is to analysis the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The thermal-structural analysis is then used coupling to determine the deformation and the Von Mises stress established in the disc, the contact pressure distribution in pads. The results are satisfactory when compared with those of the specialized literature. © 2013 Elixir All rights reserved. ARTICLE INFO Article history: Received: 11 September 2012; Received in revised form: 1 February 2013; Accepted: 19 February 2013; Keywords Brake discs, Heat flux, Heat transfer coefficient, Von Mises stress, Contact pressure. Elixir Mech. Engg. 55A (2013) 13244-13250 Mechanical Engineering Available online at www.elixirpublishers.com (Elixir International Journal)