A new appraisal of the thermomechanical behaviour of a hybrid composite brake disc in a formula vehicle
To be published on November 21, 2019 by SAE International in United States
Event: NuGen Summit
A new appraisal of the thermomechanical behaviour of a hybrid composite brake disc in a formula vehicle Research Objective This paper presents a hybrid composite brake disc with reduced Un Sprung Weight clearing thermal and structural analysis in a formula vehicle.Main purpose of this study is to analyse thermomechanical behaviour of composite brake disc for a formula vehicle under severe braking conditions. Methodology In the disk brake system, the disc is a major part of a device used for slowing or stopping the rotation of a wheel. Repetitive braking of the vehicle leads to heat generation during each braking condition. Based on the practical understanding the brake disc was remodelled with unique slotting patterns and grooves, using the selected aluminium alloy of (AA8081) with reinforcement particle of Silicon carbide (SiC) and Graphite (Gr) as a hybrid composite material for this proposed work. In First Phase of this Project work, By varying slotting pattern and groove angles the transient thermal and structural analysis using ANSYS workbench ,the hybrid composite disc plate of disk brake is done.The coupled thermal-structural analysis is used to determine the deformation and the Von Mises stress established in the disc for both solid disk and disk provided with multiple ventilations(slotting patterns and grooves angles) using the hybrid composite material to enhance the performance of the brake disc.. Recommended for fabrication and usage in formula vehicles. The second phase of this proposed work, the optimal design of the aluminium hybrid composite material disc plate was fabricated by using the liquid metal melting technique. In the fabricating work were cast disc plate by using Aluminium alloy (AA8081) as a matrix material with reinforcement particle of 10 wt% Silicon carbide (SiC) and 3 wt% Graphite (Gr) as a secondary phase element. The disc plate was preparing under stir cum squeeze-cast condition. For each casted disc plate one kilogram of AA8081 alloy ingot was dissolved in the heater at a temperature of 725oC until a homogeneous fluid stage is gotten. Amid this stage, a spread transition of 8g is utilized to clean the liquefy, and hexachloroethane (C2Cl6) of 12g is utilized as a degasser to dispose of the entrapped gases from the liquid metal. The liquid melt is agitated by the mechanical stirrer rotating at 400 rpm for 5 minutes in order to create a fine vortex. While stirring the melt, the preheated reinforcement particle of 15 wt% SiC and 3 wt% Gr along with wettability salt K2TiF6 progressively added to the melt and transfer into the 225oC preheated die, immediately squeeze pressure of 140 MPa was applied for few seconds to produce sound casted disc plate. At last, the casted disc plate samples are separated from the die cavity and the prepared disc plate was solution treated at 5400 C for 4 hrs in a furnace and quenched in water at 250C. The heat treated disc plate was artificially aged (T6) at 4 hrs. at a temperature of 1550 C and extinguished in the water at 250C. Results 1.Optimum design Pattern Groove Angles of the Brake Disc were obtained through Analysis in ANSYS. 2.The test examples are set up according to ASTM measures to assess the hardness, ultimate tensile strength, thermal properties, wear rate and coefficient of friction. Finally prepared disc plate were implemented in a formula vehicle and performance was observed and recorded for validation.Results were found to be improved. Limitations of this Study This concept can be extended to Manufacturing by NanoComposite Hybrid but Process will be expensive.This Paper is limited to Aluminium Alloy,but can be extended to Magnesium Based Alloy. Offer from the Authors that is New in this Field that differ from earlier work To Design and Develop the Optimum Slotting Patterns and Groove Angles in the Brake Disc.Additionally the Brake Disc was Fabricated using Hybrid Metal Matrix Composite Material through stir cum squeeze-casting Route Conclusion Light Weight without compromising Performance is achieved by this Design Optimisation of Slotting and Groove Angles with Hybrid Metal Matrix Composite.This is more suitable for High speed Vehicles compared to conventional Material..The prepared hybrid composite disc plate reduces the un-sprung weight of the formula vehicle without compromising the strength.