Dinâmica de frenagem e análise do comportamento térmico de discos de freio BAJA SAE

• Autor(a) principal: Rodrigues, Juliano Marques
• Data de Publicação: 2023
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• dARK ID: ark:/26339/001300000pztf
• Texto Completo: http://repositorio.ufsm.br/handle/1/31102
• topic: brakes; brake discs; braking dynamics; finite elements; thermal analysis; análise térmica; dinâmica de frenagem; discos de freio; elementos finitos; freio; CNPQ::ENGENHARIAS::ENGENHARIA MECANICA

The safety of commercial vehicles and baja SAE vehicles designed by students significantly relies on brake systems. As part of a project conducted by the Technology Center (CT) at the Federal University of Santa Maria (UFSM), Bombaja focuses on researching, designing, and sizing a single-seater OFF-ROAD prototype, including its brake system. The fundamental principle of braking dynamics involves converting the vehicle's kinetic energy into heat, dissipated through brake discs. However, the potential for brake systems to reach high temperatures poses a risk to their functionality, potentially leading to reduced braking efficiency, thermal fatigue, and brake fluid evaporation. Therefore, this project aims to analyze the thermal behavior of a front brake disc in the BJ20 prototype, comprehensively understanding the system's thermal dissipation and studying heating and cooling curves during vehicle use. This study proposes a thermal performance analysis of three brake disc geometries of a Baja SAE vehicle, using analytical, numerical (via the ANSYS finite element software), and experimental methods. These three geometries, made of two different materials (SAE 1045 steel and 304 stainless steel), were compared. Initially, a literature review on various brake types, braking dynamics, and heat generation/dissipation was conducted. Subsequently, analytical calculations for braking dynamics and heat transfer parameters were obtained. The analysis procedures included emergency braking on high-friction surfaces, twenty consecutive braking cycles on high-friction surfaces, and an endurance test on low-friction surfaces. Analytical data were compared with numerical simulations, and real temperatures of the brake disc during physical testing on tracks were recorded. Comparing materials revealed better performance of discs made from SAE 1045 steel, exhibiting lower maximum temperatures due to higher thermal conductivity compared to 304 stainless steel. Regarding geometries, the BJ15 disc showed superior thermal performance, while the BJ14 disc recorded the highest temperatures.