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After the anti-skid brake system (ABS) introduction, mandatory for all vehicles in the Brazilian market, manufacturers have given increasing attention to optimized systems which meet legal and safety requirements. For commercial vehicles, an alternative for the ABS, which presents feasibility, is the configuration 4S/3M (4 wheel-speed sensors and 3 modulator valves) in substitution to the configuration 4S/4M. In other words, application of just one modulator valve to control the brakes of the same axle, front or rear, instead of independent control per each brake of the vehicle. The aim of this paper is to present a performance comparison between a brake system fitted with ABS configuration 4S/3M and an ABS configuration 4S/4M. To this end, both configurations were tested on the same vehicle application in accordance with the Brazilian legislation, CONTRAN 519/15.

With the constant evolution of vehicle systems becomes increasingly challenging the Components project. The demand for mass and cost optimization in a challenging project schedule scenario generates a great challenge to the engineering teams, who look for design and development methods more assertive. In order to reduce the risk of failure, testing time and design cost, simulation tools are being increasingly used. A major challenge in the component project for trucks and buses is the knowledge of the real loads that the components are subjected. In the case of propeller shaft bearings several factors should influence the magnitude of the efforts. The biggest influent factors that has been studied and discussed widely for many years are the torque and joints angles.

The higher is the volume of automated transmissions for high load capacity commercial vehicles in the market, the higher is the necessity to develop auxiliary systems capable to reduce the wear of the clutch disc during start-ability performance in slopped plans. The Hill Start Assist System, HSA, is compounded by a set of components in the brake system, disposed in such a way that provides to the driver the possibility of starting to run with comfort and safety by the actuation of the service brakes, without overheating the clutch system and simultaneously avoiding the undesirable effect of composition roll-back. For this, it is only necessary that the vehicle be equipped, besides automated transmission, Anti-lock Braking System, ABS, and an active traction control in, at least, one of the drive axles.

In engineering development, simulation methods are frequently used to perform thermal and mechanical stress components analysis. In brake systems, where the components are exposed to mechanical and thermal loads, the numerical analysis is very helpful. Once a numerical model for brake assembly is available, it will be possible to understand the effects of successive brake applications on the temperature distribution in drum brake's friction materials. This is a fundamental aspect to determine, for instance, the thermal stress distribution which is related to the warming and cooling of the brakes. In this work, an analytical solution to calculate stabilized temperature was used to establish a heat flux through a pneumatic S cam drum brake's friction material applied to a numerical model in a finite element analysis.