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Da Silva J.G.P.,Fras le S.A. | Fulco E.R.,Fras le S.A. | Varante P.E.D.,Fras le S.A. | Do Nascimento V.,Master Sistemas Automotivos Ltda | And 2 more authors.
SAE Technical Papers | Year: 2013

It is widely known that a typical brake system works by mitigating vehicle kinetic energy and transforming it into thermal energy, ultimately leading to energy dissipation. The main concerns related to this kind of system are: 1) low frequency vibration energy propagating throughout the vehicle structure when the system begins its unblocking action; and 2) high frequency vibration energy propagation which induces undesirable noise levels. Modal analysis of the system can provide important information about its vibration characteristics. Provided that coupling between the dynamic behavior, the pre-stress caused by the applied load, and friction characteristics will certainly occur, it is required that analyses be performed on the entire assembly. As such, this paper presents evaluation of a brake disc system regarding the brake squeal using finite element method comparing with experimental assessment. Copyright © 2013 SAE International.

Travaglia C.A.P.,Multicorpos Engineering LTDA | Araujo J.,MAN Latin America | Bochi M.,MAN Latin America | Yoneda A.,Master Sistemas Automotivos Ltda | And 4 more authors.
SAE Technical Papers | Year: 2013

1 Commercial vehicles have been more and more equipped with more powerful engines allowing considerable increase in size and load capacity. With this increase in capacity, it becomes important to evaluate the efficiency of the brake system to ensure vehicle safety during transportation of people and materials. Braking efficiency of a vehicle is significantly affected by the heat generated by friction between stationary components and rotors. This heat raises the temperature of the components in brake assembly reducing the friction coefficient at the interface between brake lining and drum. Once the friction coefficient is reduced, the braking torque decreases. As consequence, it may cause undesirable scenarios such as braking performance loss due to overheating, tire burst, hub grease melting, brake lining failure, thermal cracking, geometric distortions and brake locking. All these scenarios directly impact the vehicle safety, generating demand for accurate predictions of components temperatures and thermal efficiency in the early stage of development. The purpose of this work is to use computational methods to simulate the cooling effect on the drums in order to provide necessary improvements in the final design of the brake. The present study describes the thermal behavior of a drum brake assembly of a MAN commercial truck by using of Computational Fluid Dynamics technique (CFD). The validation of this method will bring several benefits to the brake development, like reduction of the design time and reduction of the prototype and application tests costs. This paper describes CFD analysis of the unsteady heat dissipated through the truck rear wheels components (including hubs, brake drums, brake linings, rims and tires) after one typical cycle of brake application. After computational simulation, CFD results were validated using a dataset obtained from experimental tests. Copyright © 2013 SAE International.

Gutierrez A.S.,Ford Motor Company | Iombriller S.F.,Ford Motor Company | Prado W.B.,Ford Motor Company | Novello D.,Master Sistemas Automotivos Ltda | And 3 more authors.
SAE Technical Papers | Year: 2013

During the development of a new friction material, besides the interface between lining/drum is also fundamental take in account all aspects involving the attachment of the linings on the brake shoes. This paper presents an optimization approach to the development and manufacturing parameters of brake linings, applied on medium and heavy duty commercial vehicles, aiming to assure the correct specification of the riveted joint clamp forces. These evaluations were conducted based on the quality tools documents and the theoretical aspects of the product usage as well as the modeling of key elements of the referred mechanism throughout various known applications. A calculation methodology was developed based on brake geometry, its generated forces and braking reactions required for each vehicle family. Taking in consideration the mathematical modeling of lining riveting process, the study incorporated calculated parameters on the production of new parts to proceed with bench and dynamometer preliminary tests. After theoretical approach an optimized process of lining riveting was implemented on the riveting machine focusing on its capacity to generate the required clamp force on a production scale. With the results from experimental testing, further vehicular performance correlations were performed aiming durability endurance maximization on proving ground tracks. The main objective of this paper is to show all steps involved on defining a robust riveting process based on calculation, experimental testing and rooted on vehicular correlation and validation aspects, obtaining a method to specify the required clamp force of the riveted joint on brake linings development. Copyright © 2013 SAE International.

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