Mostefa Bouchetara

Simulation of fully coupled thermomechanical analysis of automotive brake discs

The vehicle braking system is considered to be one of the most fundamental safety-critical systems in modern vehicles, as its main purpose is to stop or decelerate the vehicle. The frictional heat generated during braking application can cause numerous negative effects on the brake assembly, such as brake fade, premature wear, thermal cracks and disc thickness variation. In the past, surface roughness and wear at the pad interface have rarely been considered in studies of the thermal analysis of a disc brake assembly using the finite element method. The ventilated pad-disc brake assembly is built by a three-dimensional model with a thermomechanical coupling boundary condition and multi-body model technique. The numerical simulation for the coupled transient thermal field and stress field is carried out sequentially with the thermal-structural coupled method, based on ANSYS software, to evaluate the stress fields of deformations, which are established in the disc with the pressure of the pads and in the conditions of tightening of the disc; thus, the contact pressure distributions field in the pads is obtained, which is another significant aspect in this research. The results obtained by the simulation are satisfactory compared with those of the specialized literature.

Modeling of thermal contact problem of disc brake system with frictional heat generation

Safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle. Each single system has been studied and developed in order to meet safety requirement. Instead of having air bag, good suspension systems, good handling and safe cornering, there is one most critical system in the vehicle which is brake systems. The objective of this work is to investigate and analyze the temperature distribution of rotor disc during braking operation using ANSYS Multiphysics. The work uses the finite element analysis techniques to predict the temperature distribution on the full and ventilated brake disc and to identify the critical temperature of the rotor. The analysis also gives us, the heat flux distribution for the two discs.

Numerical simulation and prediction of the performance of a direct injection turbocharged diesel engine

Increases in fuel prices are constraining car manufacturers to produce highly efficient engines, noting greater regulation in terms of pollutant emissions. The greater complexity of modern engines has rendered the prototyping phase long and expensive. This is where engine modeling has in recent years become extremely useful and an indispensable tool when developing new engine concepts. This study deals with the numerical simulation and performance prediction for a turbocharged diesel engine with direct injection. To predict engine performance we developed a computer program for simulating the operation of a turbocharged diesel engine, and used the commercial software GT-Power to validate the simulation results. We then carried out a comparative study of indicated mean effective pressure, mean effective pressure, power, torque and brake specific fuel consumption obtained by an analytical model for thermodynamic cycle simulation of a turbocharged diesel engine using a computer program developed in Fortran and GT-Power. The Fortran program that was developed is currently used for modeling and the simulation of engine performance.

Thermal and structural analysis of disc brake assembly during single stop braking event

Abstract An automobile disc brake system is used to perform three basic functions, i.e. to reduce speed of a vehicle, to maintain its speed when travelling downhill and to completely stop the vehicle. During these braking events, the disc brake may suffer from structural and wear issues. It is quite sometimes that the disc brake components fail structurally and/or having severe wear on the pad. Thus, this paper aims to determine disc temperature and to examine stress concentration, structural deformation and contact pressure of brake disc and pads during single braking stop event by employing commercial finite-element software, ANSYS. The paper also highlights the effects of using a fixed calliper, different friction coefficients and different speeds of the disc on the stress concentration, structural deformation and contact pressure of brake disc and pads, respectively. The thermal-structural analysis is then used with coupling to determine the deformation and the Von Mises stress established in the disc, the contact pressure distribution in pads.

Thermomechanical analysis of vehicles gray iron brake discs

Purpose – The main purpose of this study is to analyse the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase.Design/methodology/approach – The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disc is actually used to identify the factor of geometric design of the disc to install the ventilation system in vehicles. 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.Findings – The analysis results showed that temperature field and stress field in the process of braking phase were fully coupled.Originality/value – The results are satisfactory when compared with those of the specialized literature.

Thermomechanical Behaviour of Dry Contacts in Disc Brake Rotor with a Grey Cast Iron Composition

The objective of this study is to analyse the thermal behaviour of the full and ventilated brake discs of the vehicles using computing code ANSYS. The modelling of the temperature distribution in the disc brake is used to identify all the factors and the entering parameters concerned at the time of the braking operation such as the type of braking, the geometric design of the disc and the used material. The numerical simulation for the coupled transient thermal field and stress field is carried out by sequentially thermal-structural coupled method based on ANSYS to evaluate the stress and deformations on disc surface including the contact pressure on the pads. The results obtained by the simulation are satisfactory compared with those of the specialized literature.

Thermomechanical Coupling Analysis of a Disc Brake Rotor

The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disc is actually used to identify the factor of geometric design of the disc to install the ventilation system in vehicles. The thermal-structural analysis is then used to determine the deformation established, the von Mises stresses in the disc, and the contact pressure distribution in pads. The results are satisfactorily compared with those found in the literature.

The influence of different parameters on the performance of the compression ignition engine

The purpose of this work was to provide a flexible thermodynamic model based on the filling-and-emptying approach for the performance prediction of a four-stroke turbocharged compression ignition engine. To validate the model, comparisons were made between results from a computer program developed using FORTRAN language and the commercial GT-Power software operating under different conditions. The comparisons showed that there was a good concurrence between the developed program and the commercial GT-Power software. The range of variation of the rotational speed of the diesel engine chosen extends from 800 to 2100 RPM. By analysing these parameters with regard to two optimal points in the engine, one relative to maximum power and another to maximum efficiency, it was found that if the injection timing is advanced, the maximum levels of pressure and temperature in the cylinder are high.

Analytical investigation of the effect of thermodynamic and geometric parameters on the performance of a direct injection turbocharged diesel engine

The thermodynamic performance of a diesel engine with heat transfer and friction term losses is analysed. This study deals with the numerical simulation and performance prediction of a turbocharged diesel engine with six-cylinder direct injection. To predict the engine performances, we developed a computer program for simulating the operation of a turbocharged diesel engine, and used the commercial GT-Power software to validate the simulation results. The range of variation of the rotational speed of the diesel engine chosen extends from 800 rpm to 2100 rpm. In this paper, we studied the influence of several engine parameters on the brake power and effective efficiency. Moreover, it puts in evidence the existence of two optimal points in the engine, one relative to maximum power and another to maximum efficiency; it was found that if the injection time is advanced, then the maximum levels of pressure and temperature in the cylinder are high.

Parametric study of the performance of a turbocharged compression ignition engine

In this study, the thermodynamic performance of a turbocharged compression ignition engine with heat transfer and friction term losses was analyzed. The purpose of this work was to provide a flexible thermodynamic model based on the filling-and-emptying approach for the performance prediction of a four-stroke turbocharged compression ignition engine. To validate the model, comparisons were made between results from a computer program developed using FORTRAN language and the commercial GT-Power software operating under different conditions. The comparisons showed that there was a good concurrence between the developed program and the commercial GT-Power software. We also studied the influence of several engine parameters on brake power and effective efficiency. The range of variation of the rotational speed of the diesel engine chosen extended from 800 to 2100 rpm. By analyzing these parameters with regard to two optimal points in the engine, one relative to maximum power and another to maximum efficiency, it was found that if the injection timing is advanced, so the maximum levels of pressure and temperature in the cylinder are high.