Browse Topic: Brake components

Items (2,125)

Model Based NVH Simulator for Virtual Development

2025-01-0059To be published on 05/05/2025

For mature virtual development, enlarging coverage of performances and driving conditions comparable with physical prototype is important. The subjective evaluation on various driving conditions to find abnormal or nonlinear phenomenon as well as objective evaluation becomes indispensable even in virtual development stage. From the previous research, the road noise had been successfully predicted and replayed from the synthesis of system models. In this study, model based NVH simulator dedicated to virtual development have been implemented. At first, in addition to road noise, motor noise was predicted from experimental models such as blocked force and transfer function of motor, mount and body according to various vehicle conditions such as speed and torque. Next, to convert driver’s inputs such as acceleration and brake pedal, mode selection button and steering wheel to vehicle condition, 1-D performance model was generated and calibrated. Finally, the audio and visual feedback

Park, Sangyoung, Dirickx, Tom, Kang, Yeon June, Nam, Jeong Min, Gonçalves, Vinícius Valencia

Development of a Robust Framework for Fault Detection and Quantification in Automotive Drum Brakes Using Vibration Measurements and ANN

10-09-03-0024

04/15/2025

Passenger safety is of utmost importance in the automotive industry. Hence, the health of the components, especially the brake system, should be effectively monitored. On account of the significance of artificial intelligence in recent times, any brake fault resulting during operation can be accurately detected using a combination of advanced measurement techniques and machine learning algorithms. The current study focuses on developing and evaluating a robust framework to quantify and classify the faults of a general automotive drum brake. For this purpose, a new experiment for a drum brake, which can be operated under a controlled environment with known levels of faults, is developed. The experiment is instrumented to measure the fundamental dynamic signals (such as brake torque, the angular velocity of the brake drum, and brake shoe accelerations) during a braking event. The response signals from several experiments with various faults and operating conditions serve as the input

Yella, Akash, Bharinikala, Yuva Venkat Ajay, Sundar, Sriram

Automotive Air Brake Hose and Hose Assemblies

J1402_202504 (Current)

04/14/2025

This SAE Recommended Practice covers minimum requirements for air brake hose assemblies made from reinforced elastomeric hose and suitable fittings for use in automotive air brake systems, including flexible connections from frame to axle, tractor to trailer, trailer to trailer, and other unshielded air lines with air pressures up to 1 MPa, that are exposed to potential pull or impact. This hose is not to be used where temperatures, external or internal, fall outside the range of -40 to +100 °C. Provisions for extreme low temperature performance testing to -54 °C are included in the document.

Hydraulic Hose and Hose Fittings Committee

Research on Pressure Control Methods for a Dual-Source Electro-Hydraulic Brake System with Redundant Braking Function

2025-01-8716

04/01/2025

This paper presents a novel Dual-source Electro-Hydraulic Brake system (D-EHB) that incorporates a redundant braking module to enhance safety and reliability. The D-EHB is designed to address the critical issue of brake failure in vehicles, which can lead to severe accidents. The D-EHB system comprises two independent units: the Main Brake Unit (MBU) and the Redundant Brake Unit (RBU). Each unit has its own hydraulic power source. The MBU's hydraulic pressure is generated by a combination of a servo motor, ball screw, and servo piston, while the RBU has a simpler structure, with hydraulic pressure generated by a motor and plunger pump combination. Mathematical models for each component of the D-EHB have been developed and validated using AMESim. The mathematical models of each part were then combined to design a wheel cylinder hydraulic pressure estimation algorithm that can calculate the wheel cylinder pressure based on motor and valve output signals, making the system applicable to

Wang, Wenqiang, Zhao, Xuezhi, Shangguan, Wen-Bin, Ren, Bingyu

Thermomechanical Fatigue Behavior of Gray Cast Iron in Brake Rotors

2025-01-8319

04/01/2025

Gray cast iron is a cost-effective engineering material widely used for heavy duty engine blocks and brake rotor discs in vehicles. Thermomechanical fatigue (TMF) frequently occurs during vehicle operation due to temperature fluctuations in brake rotors. To speed up the design of the component, design structurally sounding brake rotors, and prevent premature thermally induced cracking, it is critical to investigate TMF behavior of the gray cast iron. This study presents a series of fatigue tests, including isothermal low cycle fatigue (LCF) tests at temperatures up to 700°C, as well as in-phase (IP) and out-of-phase (OP) TMF tests across various temperature ranges. Because of the asymmetric behavior in tension and compression, creep behaviors in both tension and compression and oxidation are also studied. These behaviors are the key to enable simulation of thermally induced cracks in rotors.

Liu, Yi, Lee, Heewook, Hess, Devin, Coryell, Jason

High-Quality Clamping Force Control for Electro-Mechanical Brake Considering Nonlinear Disturbances

2025-01-8304

04/01/2025

The Electro-Mechanical Brake (EMB) eliminates the traditional hydraulic pipeline arrangement through high-performance servo motor at the vehicles brake calipers. This provides a foundation for intelligent electric vehicles to achieve high-precision, fast response, and strong robustness in brake clamping force control. However, EMB faces some tricky nonlinear disturbances such as varying system stiffness disturbances, complex friction obstruction, etc., which leads to a decline in clamping force control performance. Therefore, this paper proposes a high-quality clamping force control for EMB considering nonlinear disturbances. First, we establish an EMB actuator model including the permanent magnet synchronous motor, mechanical transmission mechanism, and system stiffness characteristics. Next, the high-quality clamping force control strategy for EMB is designed. An outer-loop clamping force regulator is developed using Proportional-Integral-Derivative (PID) feedback control and

Zhao, HuiChao, Chen, Zhigang, Li, Lun, Wang, Zhongshuo, Wu, Jian, Chen, Zhicheng, Zhu, Bing

Evaluation and Prevention of Brake Drum Freezing by Aerodynamic Measures

2025-01-8775

04/01/2025

The use of drum brakes in Battery Electric Vehicles (BEVs) offers numerous benefits, including energy efficiency, reduced brake dust emissions, and reliable performance under challenging weather conditions. The capability of regenerative braking reduces the friction brake application frequency in BEVs and therefore the brakes can be prone to corrosion and performance degradation especially considering conventional disc brake systems. The closed design of a drum brake prevents corrosion of the friction-components by sealing out water, dirt or snow. A common sealing concept is performed with a labyrinth between the gap of the rotating drum and the axle mounted backplate. A hermetical isolation of water and snow ingress into the drum cannot be achieved with this concept, so additional aerodynamic measures are necessary to deflect the air/water path and protect the inner brake components. Additionally, interfaces like wheel cylinders, electric park brake parts, brake shoe pins, and axle

Hennicke, Tim, Kuthada, Timo, Bernhard, Adrian, Reichhart, Leander, Weber, Eugen, Moers, Michael, Rettig, Marc

A Design of Electric Drive System for All-Wheel Drive Formula Student Racing Car to Improve Racing Performance

2025-01-8005

04/01/2025

This paper introduces an innovative in-wheel electric drive system designed for all-wheel drive Formula Student Electric racing cars. The system utilized AMK's DD5-14-10-POW-18600-B5 model as the driving motor, with a gearbox transmission ratio of 13.2 determined through Optimum Lap simulation. A two-stage gear reducer was integrated into a unified hub-spoke assembly, which connected directly to the ten-inch carbon fiber rim. In this paper, three conventional FSEC planetary gear reducer shafting designs are introduced, and a new shafting structure is proposed. Then the four structures are compared in multiple dimensions. Subsequently, we designed the shafting of the gear group, determined the size parameters of the shafting structure and the bearing type, and completed the verification. The planetary carriers were integrated with the wheel-edge suspension columns. Meanwhile, a special floating brake disc mounting method was employed, which increased the brake disc's heat capacity by

Guo, Ruijie, Zeng, Junhao, Yang, Yuancai, Hou, Yijie, Zhu, Zhonghui, Xiong, Jiaming

A Control and Fault-Tolerant Strategy Based on Electromechanical Brake System

2025-01-8265

04/01/2025

With the development of automotive electrification and intelligent technology, vehicles have higher and higher requirements for braking systems. On the one hand, it requires it to have an active braking function, and at the same time facilitates the integration with other control systems of the chassis domain. The system should minimize oil pollution as much as possible, and under the premise of ensuring the pedal force, it can be used to recover the brake energy as much as possible to improve the range of electric vehicles as possible. The new brake system based on Electronic mechanical brake (EMB) as a line -controlled decoupling braking system can not only meet the needs of the brake pedal sensation, but also achieve continuous and accurate control of braking power. It can effectively Taking into account braking economy, braking safety, and braking comfort. In addition, the development of EMB technology is still immature and the failure rate is high, so research on EMB's fault

Li, Xuesong, Qin, Keyun, Zheng, Hongyu, Kaku, Chuyo

Material-Combined Vehicle Brake Disc Design for Enhanced Cooling Performance

2025-01-8189

04/01/2025

The improvement of heat dissipation performance of ventilated brake discs is vital to braking safety. Usually, the technical approaches shall be material optimization or structural improvement. In this paper, a simulation model of the heat transfer of brake discs is established using STAR-CCM+ software. Cast iron, aluminum metal matrix composite (Al-MMC), and carbon-ceramic composite materials (C-SiC) are compared. The results show that: Al-MMC has better thermal conductivity so that a more uniform temperature gradient distribution shall be formed; C-SiC has poorer heat capacity yet, according to previous studies, it has better thermal stability, which is the ability to ensure its friction factor under high-temperature condition; cast iron performs better with convective heat transfer rate, which enhances the heat transfer between the surface and surrounding flow field. Based on the results, this paper proposes four types of material combined brake discs using different friction

Wang, Jiarui, Jia, Qing, Zhao, Wentao, Xia, Chao, Yang, Zhigang

Concept of an Electromechanical Brake-By-Wire System for Battery-Electric Vehicles

2025-01-8804

04/01/2025

Brake-by-wire systems have received more and more attention in the recent years, but a close look on the available systems shows, that they have not reached full by-wire level yet. Most systems are still using hydraulic connections between main cylinder and the brake calipers on at least one axle to ensure functional safety. Mostly, this is the front axle, since the front brakes have to convert more kinetic energy during braking manoeuvers. Electromechanical actuators are currently used for rear brakes in hybrid brake-by-wire applications solely, since a loss of the front brake calipers can lead to severe conditions and control loss of the vehicle during braking. Further, the higher mass of battery electric vehicles (BEVs) leads to much higher braking forces on both axles and to increased sizes of the electromechanical calipers. This article presents a concept for a brake-by-wire system for battery electric vehicles, which features electromechanical brake actuators on all corners and a

Heydrich, Marius, Lenz, Matthias, Ivanov, Valentin, Stoev, Julian, Lecoutere, Johan

Fluid Topology Optimization for Heat Dissipation of Ventilated Brake Discs

2025-01-8183

04/01/2025

Enhancing the heat dissipation performance of ventilated brake discs is a complex challenge involving fluid dynamics, solid mechanics, rotational motion, thermal transfer, and frictional interactions. To address this issue, this study developed a comprehensive simulation model for brake disc heat dissipation, informed by wind tunnel testing conducted on a multi-purpose vehicle (MPV) model. The research included a sensitivity analysis of design parameters related to the brake disc blades and employed a topology optimization approach to enhance the disc's heat dissipation capabilities. The study successfully demonstrated the applicability of topology optimization to the intricate thermal simulation of brake discs. As a result, a novel brake disc blade design with a unique geometry was developed, and the underlying principles contributing to its improved thermal performance were thoroughly analyzed. The optimized brake disc design, distinguished by a carefully contoured inlet curve and a

Zhao, Wentao, Jia, Qing, Qin, Lanwei, Xia, Chao, Chao, Han, Daxin, Jiang, Yang, Zhigang

Energy-Efficient Maneuvering of Connected and Automated Vehicles: NEXTCAR Phase II Results

2025-01-8385

04/01/2025

Onboard sensing and Vehicle-to-Everything (V2X) connectivity enhance a vehicle's situational awareness beyond direct line-of-sight scenarios. A team led by Southwest Research Institute (SwRI) demonstrated 20% energy savings by leveraging these information streams on a 2017 Prius Prime as part of the first phase of the ARPA-E-funded NEXTCAR program. Combining this technology with automation can improve vehicle safety and enhance energy efficiency further. In the second phase, SwRI demonstrated 30% energy savings over the baseline. This paper summarizes the efforts to achieve 30% savings on a 2021 Honda Clarity PHEV. The vehicle was outfitted with the SwRI Ranger automated driving suite for perception and localization. Model-based control schemes with selective interrupt and control (SIC) were used to override stock vehicle controls and actuate the accelerator, brake, and electric power steering system, enabling drive-by-wire and steer-by-wire functionalities. Key algorithms contributing

Bhagdikar, Piyush, Gankov, Stanislav, Sarlashkar, Jayant, Hotz, Scott, Rajakumar Deshpande, Shreshta, Rengarajan, Sankar, Adsule, Kartik, Drallmeier, Joseph, D'Souza, Daniel, Alden, Joshua, Bhattacharjya, Shuvodeep

The Accuracy of Vehicle Speeds, Decelerations, and Brake Onset Times Calculated from Onboard Dash Cameras

2025-01-8691

04/01/2025

Videos from cameras onboard a moving vehicle are increasingly available to collision reconstructionists. The goal of this study was to evaluate the accuracy of speeds, decelerations, and brake onset times calculated from onboard dash cameras (“dashcams”) using a match-moving technique. We equipped a single test vehicle with 5 commercially available dashcams, a 5th wheel, and a brake pedal switch to synchronize the cameras and 5th wheel. The 5th wheel data served as the reference for the vehicle kinematics. We conducted 9 tests involving a constant-speed approach (mean ± standard deviation = 57.6 ± 2.0 km/h) followed by hard braking (0.989 g ± 0.021 g). For each camera and brake test, we extracted the video and calculated the camera’s position in each frame using SynthEyes, a 3D motion tracking and video analysis program. Scale and location for the analyses were based on a 3D laser scan of the test site. From each camera’s position data, we calculated its speed before braking and its

Flynn, Thomas, Ahrens, Matthew, Young, Cole, Siegmund, Gunter P.

Research on Shuffle Reduction Control in Dual Motor Hybrid System Based on the Motor Torque Intervention

2025-01-8517

04/01/2025

Due to the frequent and significant changes of the motor torque of hybrid vehicles during driving often occurring with the driving conditions, and the existence of the transmission tooth surface switching caused by the change in torque direction, as well as the underdamping characteristics caused by the relatively simple transmission system, the vehicle is prone to vehicle body shaking problems under conditions such as the transformation from acceleration conditions to energy recovery conditions, and exit from energy recovery. In order to ensure the ride smoothness of the hybrid vehicle while improving its power response performance, aiming at the underdamping characteristics of its transmission system, this paper develops a transmission PCM vibration suppression control strategy based on the vehicle control system to enhance the torque response and smoothness after Tip out or Tip in after braking. This strategy includes the identification of preconditions and the active intervention

Jing, Junchao, Zhang, Junzhi, Zuo, Botao, Liu, Yiqiang, Huang, Weishan, Xue, Tianjian

Research on Pedal Operation Characteristics for Detecting Pedal Misapplication

2025-01-8675

04/01/2025

Drivers sometimes operate the accelerator pedal instead of the brake pedal due to driver error, which can potentially result in serious accidents. To address this, the Acceleration Control for Pedal Error (ACPE) system has been developed. This system detects such errors and controls vehicle acceleration to prevent these incidents. The United Nations is already considering regulations for this technology. This ACPE system is designed to operate at low speeds, from vehicle standstill to creep driving. However, if the system can detect errors based on the driver's operation of the accelerator pedal at various driving speeds, the system will be even more effective in terms of safety. The activation threshold of ACPE is designed to detect operational errors, and it is necessary to prevent the system from being activated during operational operations other than operational errors, i.e., false activation. This study focuses on the pedal operation characteristics of pedal stroke speed and

Natsume, Hayato, Shen, Shuncong, Hirose, Toshiya

Anti-Noise Brake Pads Shims: T-Pull Test and Bond Coverage

J2694_202503 (Current)

03/05/2025

This recommended practice covers the attachment of bonded anti-noise brake pad shims only. Mechanically attached shims (those without bonding) are not covered by this procedure.

Brake Linings Standards Committee

Enhancing Disc Brake Performance: Investigating Squeal Noise, Wear, and the Application of Functionally Graded Materials in Brake Rotors

2025-28-0162

02/07/2025

Disc brakes play a vital role in automotive braking systems, offering a dependable and effective means of decelerating or halting a vehicle. The disc brake assembly functions by converting the vehicle's kinetic energy into thermal energy through friction. The performances of the brake assembly and user experience are significantly impacted by squeal noise and wear behaviour. This paper delves into the fundamental mechanisms behind squeal noise and assesses the wear performance of the disc brake assembly. Functionally graded materials (FGMs) are an innovative type of composite material, characterized by gradual variations in composition and structure throughout their volume, leading to changes in properties such as mechanical strength, thermal conductivity, and corrosion resistance. FGMs have emerged as a groundbreaking solution in the design and manufacturing of brake rotors, addressing significant challenges related to thermal stress, wear resistance, and overall performance. These

C V, Prasshanth, S, Gurumoorthy, Bhaskara Rao, Lokavarapu, S, Sridhar, S, Badri Narayanan, Kumar, Ajay, Biswas, Sayan

Composite Brake Pads Reinforcement with Natural Fiber: A Comparative Analysis of Mechanical and Thermal Properties

2024-01-5112

12/30/2024

This work pioneers the development of eco-friendly brake pads using coconut fiber and sawdust as reinforcement materials, combined with abrasives and friction modifiers. The innovation lies in the utilization of these natural fibers, which are not only cost-effective and abundantly available but also contribute to the sustainability of brake pad manufacturing. The study aims to explore the feasibility and performance of these organic fibers in brake pad applications. Coconut fiber and sawdust were chosen for their unique properties, such as high strength-to-weight ratio and thermal stability, making them ideal candidates for enhancing brake pad performance. The inclusion of abrasives and friction modifiers further optimizes the braking efficiency and durability of the pads. Comprehensive testing was conducted, including hardness, compression, wear (using a pin-on-disc apparatus), and thermogravimetric analysis (TGA), to thoroughly evaluate the mechanical properties and thermal

Ajay Devan, V., Gunasekar, N., Ravikumar, K., Balaguru, B. A., Deepak, S.

Brake Pedal Sizing and Preliminary Design of Balance Bar in the Brake of a SAE Formula Type Vehicle

2024-36-0054

12/20/2024

The SAE Formula prototypes are developed by students, where in the competition, various aspects of project definitions are evaluated. Among the factors evaluated for scoring is the braking system, in which the present work aims to present the development and design of the braking system of a vehicle, prototype of Formula SAE student competition. As it is a project manufactured mostly by students, where the chassis, suspension system, electrical, transmission and powertrain are developed, it is important to first pass the static and safety tests, where the brakes of the four wheels are tested during deceleration at a certain distance from the track. To enable such approval and also to demonstrate, for the competition judges, the veracity of the system’s sizing, all the parameters and assumptions of the choice of the vehicle’s braking system are presented, thus ensuring their reliability, efficiency and safety. Using drawing and simulation software such as SolidWorks and Excel for

Gomes, Lucas Olenski, Grandinetti, Francisco José, Martins, Marcelo Sampaio, Souza Soares, Alvaro Manoel, Reis de Faria Neto, Antônio, Castro, Thais Santos, Almeida, Luís Fernando

Brake Rotor Thickness Variation and Lateral Run-Out Measurements

J3111_202412 (Current)

12/12/2024

This SAE Recommended Practice is derived from common methods used within the industry and is not intended to validate a given design or configuration. This SAE Recommended Practice applies to vehicles below 4540 kg of gross vehicle weight rating.

Brake NVH Standards Committee

Road Vehicles - Friction Materials - Finished Brake Pad Normalized Elastic Constant of Friction Material

J3175_202412 (Current)

12/06/2024

This SAE standard specifies a method for testing and measuring a normalized elastic constant of brake pad assemblies using ultrasound. This document applies to disc brake pad assemblies and its coupons or segments used in road vehicles.

Brake Linings Standards Committee

A Simulation Based Methodology for Optimizing Correlation of Brake Disc Temperature

2024-28-0183

12/05/2024

Brake disc temperature is a critical factor influencing the performance and wear characteristics of braking systems in automobiles. Hence it is very important to optimize the correlation of brake disc temperature prediction with test. In this study critical parameters of Brake Disc temperature evaluation are identified, and algorithm is used to optimize the critical parameters to achieve the correlation of prediction with experiment data. Through a series of controlled experiments and simulations, disc temperatures are monitored under different braking conditions and simultaneously input parameters for prediction are optimized to achieve the correlation. Statistical methods were applied to evaluate the observed correlations and to model the predictive behavior of brake disc temperatures. Finally, A front-loading tool is developed to optimize the brake disc keeping target thermal capacity via algorithm. The findings of this study are expected to contribute to the enhancement of brake

Negi, Ayush Singh, Kochhar, Raman

12/01/2024

10/10/2024

TOC

Tobolski, Sue

Understanding the Actuation Point Stiffness of Electromechanical Drum Brakes

15-18-01-0002

09/24/2024

Electromechanically actuated drum brakes are one interesting option for the realization of brake-by-wire systems for future electric vehicles. A key characteristic for the design and control of electromechanical brake actuators is the actuation point stiffness, as this quantity relates the actuation force to the required actuator position. The various known approaches for the control of electromechanical brakes, which primarily focus on disc foundation brakes, typically rely on the stiffness curve at least to some extent. A transfer of these approaches to drum brakes is not straightforward, because the actuation point stiffness for drum brakes is much more complex compared to disc brakes. In particular, a strong hysteretic behavior is observed for the standing drum and a considerable change of the stiffness and hysteresis can be observed for the rotating drum. Although drum brakes have been used for decades these effects have not been thoroughly discussed in literature, yet. Hence

Peter, Simon, Janhsen, Michael, Stümke, Daniel, Görges, Daniel

Structural and Thermal Analysis of Brake Disc with Various Composites

2024-28-0066

09/19/2024

The essential aspect of an automobile is its braking system. Brakes absorb the kinetic energy of the rotating parts, i.e., wheels, and dissipate this energy into the surroundings in the form of heat. This entire process is quite complex, and the brake disc is subjected to extreme thermal and structural stresses along with deformation, which might damage the disc. This paper presents a structural and thermal analysis of an Audi Q3 brake disc using an ANSYS 2021-R1. The present brake disc is designed using SOLIDWORKS software. Composite materials are added in the ansys material library by adding their respective characteristics. The thermal analysis mainly focused on temperature variation and directional heat flux. The structural study was conducted to understand the stresses developed during braking and the deformations observed. Along with a comprehensive structural and thermal analysis, this work has also estimated the life of the brake disc, the factor of safety, and the real-time

Bahulekar, Atharv, Shiralkar, Shaunak, Jomde, Amit, Shamkuwar, Sonal, Patane, Prashant, Shinde, Tarang, Dandin, Shahbaz

Niobium Alloyed Ferritic Nitrocarburized Brake Rotors

2024-01-3031

09/08/2024

Niobium (Nb) alloyed Grey cast iron in combination with Ferritic Nitrocarburize (FNC) case hardening heat treatment is proposed to improve wear resistance and reduce brake dust generation of brake rotors. Standard Eutectic and Hypereutectic Grey irons alloyed with Niobium were evaluated in comparison to baseline unalloyed compositions. Brake speed snub sensitivity tribological testing was performed on a matrix including Niobium alloyed, Unalloyed, FNC, Non FNC, Non-Asbestos Organic (NAO) friction and Low metallic (Low Met) friction materials. Full size brake rotors were evaluated by Block Wear and Corrosion Cleanability. Improved wear, corrosion resistance and reduced brake dust debris were demonstrated by the Niobium alloyed FNC brake rotor combinations. Corrosion is an important consideration when evaluating brake performance. Combining cyclic corrosion and brake rotor testing provides the best comparison with field exposure.

Holly, Mike

Glow Discharge Optical Emission Spectroscopy Study of Cr(III) Sealing in Anodized Aluminum-Silicon Alloys

2024-01-3038

09/08/2024

The work investigates the penetration depth of a low environmental impact Cr(III)-based sealing on two anodized Aluminum-Silicon alloys (i.e., EN AC-42200 and EN AC-43200) for brake system applications. EN AC-42200 and EN AC-43200 specimens are: 1) obtained by sectioning of gravity cast components; 2) anodized using different process times to obtain different anodic layer thicknesses; and 3) sealed in a Cr(III)-based proprietary sealing solution at low temperature. The obtained sealed anodic layers are characterized using several techniques including: Glow Discharge Optical Emission Spectroscopy (GDOES), metallographic analyses and Eddy current thickness measurements. Results demonstrate that: a) the Cr(III) concentration within the anodic layers shows an exponentially decreasing trend from the specimen surface toward the anodic layer-substrate interface; b) the typical thickness of the sealing layer is in the order of 1.5μm; and c) the Cr(III) penetration depth is only marginally

Pavesi, Arianna, Fumagalli, Luca, Abello, Mary Angel, Bonfanti, Andrea, Mancini, Alessandro, Vedani, Maurizio, Bertasi, Federico

Investigation on Brake-Drag-Optimization on Vehicle-Level

2024-01-3037

09/08/2024

Brake drag in disc brakes occurs during the off-brake-phase, when the brake is not applied but friction contacts between brake disc and pads persist. First and foremost, the resulting drag torque increases energy consumption, where a few Newton meters can have a significant impact on the crucial factor – range – of battery-electric-vehicles. Moreover, brake wear is accelerated in conjunction with enlarged taper-wear of the pads. Additional wear can also imply increased brake particle emissions which are going to be limited by upcoming regulations due to their potential health risk. In this light different countermeasures aim to create and maintain a sufficient air gap between brake disc and pads when the brake is released to avoid residual friction contacts. Among others these include optimization of piston retraction by adjusting the seal-grooves and integrating pad springs into the caliper to push the pads back. State of the art to analyze the effectiveness of countermeasures are

Huchtkoetter, Philipp, Neubeck, Jens, Wagner, Andreas

Low-Speed Stop and Near Zero-Speed Start-to-Move Brake Noise: Effect of Moisture Adsorption, Prior Braking and Deceleration Rate

2024-01-3057

09/08/2024

The influence of moisture adsorption, prior braking, and deceleration rate on the low-speed braking noise has been investigated, using copper-free disc pads on a passenger car. With increasing moisture adsorption time, decreasing severity of prior braking or increasing deceleration rate, the noise sound level increases for the air-borne exterior noise as well as for the structure-borne interior noise. The near-end stop noise and the zero-speed start-to-move noise show a good correlation. Also, a good correlation is found between the noise measured on a noise dynamometer and on a vehicle for the air-borne noise. All the variables need to be precisely controlled to achieve repeatable and reliable results for dynamometer and vehicle braking groan noise tests. It appears that the zero-speed start-to-move vehicle interior noise is caused by the pre-slip vibration of the brake: further research is needed.

Sriwiboon, Meechai, Rhee, Seong Kwan, Sukultanasorn, Jittrathep, Kunthong, Jitpanu

Time for a Model Change - Inorganic Friction Materials

2024-01-3042

09/08/2024

This paper’s aim is to explain alternative friction lining formulations based on inorganic polymer binders for the production of new, future-proof brake friction materials. The aspects of high-temperature stability in the fading tests of the AKM- and AMS tests, as well as the reduction in PM10 emissions compared to classic organic friction materials, make these materials particularly fascinating for future use. Additionally, the energy savings potential of this type of friction lining could be of particular importance when sustainability considerations further influence our development activities in friction brake related applications.

Milczarek, Roman Paul, Wittig, Niels

Moisture Adsorption and Compression Deformation Behavior of Semimet vs. NAO Brake Pads: Effect of Pad Cure Temperatures and Moisture Adsorption on Low-Speed Friction

2024-01-3056

09/08/2024

Moisture adsorption and compression deformation behaviors of Semimet and Non-Asbestos Organic brake pads were studied and compared for the pads cured at 120, 180 and 240 0C. The 2 types of pads were very similar in moisture adsorption behavior despite significant differences in composition. After being subjected to humidity and repeated compression to 160 bars, they all deform via the poroviscoelastoplastic mechanism, become harder to compress, and do not fully recover the original thickness after the pressure is released for 24 hours. In the case of the Semimet pads, the highest deformation occurs with the 240 °C-cure pads. In the case of the NAO pads, the highest deformation occurs with the 120 0C-cure pads. In addition, the effect of pad cure temperatures and moisture adsorption on low-speed friction was investigated. As pad properties change all the time in storage and in service because of continuously changing humidity, brake temperature and pressure, one must question any

Rhee, Seong Kwan, Rathee, Aman, Singh, Shivraj, Sharma, Devendra

Objectively Quantify Creep Groan and Dynamic Grunt Performance of Different Brake Friction Materials

2024-01-3035

09/08/2024

The assessment of brake friction materials extends beyond squeal noise and thermal roughness testing as it play crucial role in other brake noise phenomena such as creep groan and dynamic grunt. These low frequency noise types are significant as they directly affect passengers comfort levels. Creep groan noise defined as audible stick-slip noise at low vehicle speed during partial brake application, typically encountered in dense traffic conditions. Dynamic grunt is another form of stick-slip noise observed during high-speed braking and it is noticeable just prior to vehicle’s complete stop. This noise is indicative of frictional interaction between the brake pad and disc under deceleration scenario. Comparative analysis of two distinct brake friction materials was conducted utilizing both NVH dynamometer and real-world vehicle testing. The NVH dynamometer procedure was designed to evaluate the creep groan and dynamic grunt phenomena under controlled environmental conditions. For the

Barot, Ankit, Wang, Weicherng

Analysis of Disc-Brake Squeal Considering Lining Wear

2024-01-3036

09/08/2024

Brake squeal is a phenomenon caused by various factors such as stiffness of brake components, mode coupling, friction coefficient, friction force variation, pressure, temperature and humidity. FEA simulation is effective at predicting and investigating the cause of brake squeal, and is widely used. However, in many FEA simulations, models of brake lining are mostly a brand-new shaper, so that the change of pressure distribution or pad shape, which can occur due to the lining wear, are not taken account. In this research, brake squeal analysis was conducted with consideration of lining wear, applying Fortran codes for Abaqus user subroutine. The brake assembly model for the analysis is created by using a 3D scanner and has a close shape to the real one. The wear patterns calculated by the analysis are similar to those of brake pads after a noise test. The complex eigenvalue analysis shows two unstable modes at the frequency of squeal occurred in the noise test. One is out-of-plane

Ikegami, Tokunosuke, Millsap, Tom, Yamaguchi, Yoshiyuki

Brake Particle Emission Influenced by Grooved Disc Friction Surfaces with or without a Hard Coating

2024-01-3030

09/08/2024

Many performance sport passenger vehicles use drilled or grooved cast iron brake rotors for a better braking performance or a cosmetic reason. Such brake rotors would unfortunately cause more brake dust emission, appearing with dirty wheel rims. To better understand the effects of such brake rotors on particle emission, a pin-on-disc tribometer with two particle emission measurement devices was used to monitor and collect the emitted airborne particles. The first device was an aerodynamic particle sizer, which is capable of measuring particles ranging from 0.5 to 20 μm. The second device was a condensation particle counter, which measures and collects particles from 4 nm to 3 μm. The testing samples were scaled-down brake discs (100 mm in diameter) against low-metallic brake pads. Two machined surface conditions (plain and grooved) with uncoated or ceramic-coated friction surfaces were selected for the investigation. The results showed that the grooved friction surface led to a higher

Cai, Ran, Nie, Xueyuan, Lyu, Yezhe, Wahlström, Jens

Initial Corrosion and Wear Behavior of Brake Rotors Treated with Plasma Electrolytic Aluminating or Ferritic Nitrocarburizing Process

2024-01-3043

09/08/2024

To combat corrosion and wear issues of automotive brake discs, many manufacturers have introduced various surface treatment technologies, such as thermal spraying, laser cladding, and ferritic nitrocarburizing (FNC). Besides those surface treatment technologies, a plasma electrolytic aluminating (PEA) process has also shown to be effective in producing alumina-based ceramic coatings on cast iron substrates, providing an enhanced corrosion resistance. In this study, the PEA-coated brake rotor and FNC-treated brake rotor were comparatively tested in various corrosion conditions, including an electrochemical corrosion test and simulative corrosion experiment, before and after a road driving test. A scanning electron microscope (SEM) and an energy-dispersive X-ray (EDX) were used to observe and analyze morphology and chemical compositions of the surfaces and cross-sections of the tested rotors. The results showed that the new PEA-coated brake rotor demonstrated the best corrosion

Liu, Yinting, Nie, Xueyuan

Enhancing Brake Performance: FNC-Smart-ONC® Technology to Address Corrosion Challenges and Extend the Durability of GCI Rotors

2024-01-3044

09/08/2024

The most used rotor material is gray cast iron (GCI), known for its susceptibility to corrosion. The impact of corrosion on the braking system is paramount, affecting both braking performance and the emission of particulate matter. The issue becomes more severe, especially when the brakes are left stationary or unused for extended durations in humid conditions, as seen with electric vehicles (EVs). Brake disc corrosion amplifies the risk of corrosion adhesion between contacting surfaces, leading to substantial damage, increased quantity and mass of non-exhaust particulate emissions, and decreased braking effectiveness. In addition, brake pads' friction material plays a crucial role in generating the necessary stopping force, creating friction that transforms kinetic energy into heat. However, heightened pressure during braking elevates rotor temperatures, contributing to the degradation of the friction material. This degradation manifests in decreased mechanical strength, heightened

Nousir, Saadia, Winter, Karl-Michael

Piston and Guide-Pin Rattle Noise Mitigation in Electro-Mechanical Brake Caliper

2024-01-3032

09/08/2024

Brake caliper commonly utilizes rubber or spring components to maintain specific clearance range for sliding characteristics, rendering them susceptible to rattle noise. The Electro-Mechanical Brake (EMB) caliper has attracted attention for its advantageous features such as reduced brake drag, optimized vehicle layout, and precise brake control. However, the inclusion of additional components related to the dry-type pressurizing system results in increased caliper weight and susceptibility to rattle noise. This study thoroughly examines rattle noise characteristics in our prototype EMB caliper, identifying primary noise sources on the piston and guide-pin sides. Implementing piston seals and guide-pin boots tightening force proves the effectiveness in improving rattle noise characteristics. Collisions between the piston and ball-screw head can be mitigated by piston inner seal, significantly reducing rattle noise. The effectiveness of the piston outer seal is limited and can be

Yoon, Boram, Jeon, Kyeong Hun, Boo, Sangpil, Shin, Choongsik, Kim, Tae Hoon

Analysis of Stick-slip Phenomenon During Creep Groan Using Acoustic Emission Sensing

2024-01-3033

09/08/2024

When the brakes are released and the vehicle starts, the brakes and suspensions vibrate and the car body resonates at 10 to 300 Hz, which is called brake creep groan. This low-frequency noise is more likely to occur in high-humidity environments. As vehicles become quieter with the introduction of EVs, improving this low-frequency noise has become an important issue. It is known that the excitation force is the stick-slip between the brake rotor and pads, but there are few studies that directly analyze stick-slip occurring in a vehicle. Acoustic emission (AE) is a phenomenon in which strain energy stored inside a material is released as elastic stress waves, and AE sensing can be used to elucidate the friction phenomena. In this study, the AE sensing is used to analyze changes in the stick-slip occurrence interval and generated energy when creep groan occurs. As a result, it was confirmed that the AE signal increased with high humidity. Furthermore, the friction phenomena during creep

Toyoda, Hajime, Yazawa, Yusuke, Arai, Shinichi, Ono, Manabu, Hara, Yasuhiro, Hase, Alan

Thermal coupled structural analysis of a brake disc

2024-36-0305

08/09/2024

Designing a brake disc is a very challenging job. Besides to being a key item in vehicle safety, we are referring to a product that goes through several manufacturing processes and during its application it is exposed to extreme conditions of mechanical stress, temperature and vibration. The raw material for a large portion of commercial brake discs is normally gray cast iron with the possibility of adding alloy elements. This material is characterized by having high resistance to wear due to friction and having practically zero plasticity. As it is a material without a plastic working regime, it is very important to properly size the product for use, once the material’s resistance limit is reached, a catastrophic failure in operation may be inevitable. Quality control systems in casting and machining have great importance in the development of the disc, but physical tests are always essential in this type of product. Dynamometer tests are great options for validating brake discs, due

Deckmann, Jardel Luis, do Nascimento, Vagner

Development of Brake Shoe with Carbon Footprint Reduction

2024-36-0311

08/09/2024

Considered one of the greenest forms of transport, the rail industry is at an exciting point pursuing several key initiatives to decarbonise its operations, assets, and supply chains. Therefore, having a brake shoe with a lower carbon footprint is essential for achieving the goals related to decarbonizing the operation, as it is a wear item. For this purpose, a carbon footprint measurement methodology was applied to the development of a friction material for railway brake shoes in order to reduce the carbon footprint generated in the production of the material, combining a sustainable material with greater durability in operation, thus reducing the total cost of ownership. In order to assess the advantages of the new product, a comparative analysis was carried out of the carbon footprint of the conventional shoe and the new railway shoe proposal, both used in the same application, considering the performance and environmental impact of each raw material and stage of the production

Casagrande, R.B., De Souza, A.R.A., Finimundi, A.V., Pereira, C.H.S, Masotti, D., Rombaldi, R.J., Gotardo, T.

Microstructural Analysis and Tribological Performance of Composite Iron Sulfides in Automotive Brake Pads

2024-36-0322

08/09/2024

This research explores the tribological characteristics of brake friction materials, focusing on synthetic iron-based sulfides with unique microstructures. Tribological testing, conducted per the SAE J2522 and SAE J2707 standards across diverse temperatures, reveals the superior performance of brake pads incorporating composite iron sulfide, especially at high temperatures. These pads exhibit stable friction levels and reduced wear compared to those utilizing pure iron sulfide, signifying a noteworthy advancement in overall tribological properties. A comprehensive cross-sectional analysis of friction materials using Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM/EDS) reveals chemical alterations. Pure iron sulfide undergoes extensive oxidation compared to composite iron sulfide, which exhibits oxidation near the friction surface due to differences in the oxidation mechanism because of the differential microstructure. Furthermore, Thermogravimetric Analysis

Jara, Diego Chavez, Lorenzana, Carlos, Cotilli, Edoardo, Sliepcevich, Andrea, Conforti, Michael

Application of Neural Networks for Real-Time Decision Support in Virtual Approval of Brake Components

2024-36-0306

08/09/2024

This study aims to present a virtual numerical validation procedure for durability in brake system components, using artificial neural networks and based on experimental bench tests. The study focus was concentrated on the drum brake spider component, responsible for mechanically connecting the brake system subassemblies. To develop the validation procedure, engineering software such as ABAQUS, Fe-Safe, Minitab, and MATLAB was used. These were crucial for carrying out stress analyses, statistical data validation, and construction of an Artificial Neural Network (ANN) capable of predicting finite element responses, fatigue life, and supporting real-time decision-making for structural validation of mechanical components. The results obtained from these tools allowed the calibration of a numerical virtual model using the Finite Element Method (FEM) based on mechanical theories and results obtained in bench tests with the brake system, thus, a finite element database was generated for the

Marcon, Lucas, Vieceli, Alexandre, Corso, Leandro

Brake Rotor Thermal Cracking Procedure for Vehicles Below 4 540 kg GVWR

J2928_202405 (Current)

05/17/2024

This recommended practice is derived from common test sequences used within the industry. This procedure applies to all on-road passenger cars and light trucks up to 4 540 kg of GVWR. This recommended practice does not address other aspects such as performance, NVH, and durability. Test results from this recommended practice should be combined with other measurements and dynamometer tests (or vehicle-level tests), and acceptance criteria to validate a given design or configuration.

Brake Dynamometer Standards Committee

Proposed Test Method for Brake Pad Lining Robustness in Cold Conditions

2024-01-5049

04/24/2024

With globalization, vehicles are sold across the world throughout different markets and their automotive brake systems must function across a range of environmental conditions. Currently, there is no current standardized test that analyzes brake pads’ robustness against severe cold and humid environmental conditions. The purpose of this proposed test method is to validate brake system performance under severe cold conditions, comparing the results with ambient conditions to evaluate varying lining materials’ functional robustness. The goal of this paper is to aid in setting a standardized process and procedure for the testing of automotive brakes’ environmental robustness. Seven candidate friction materials were selected for analysis. The friction materials are kept confidential. Design of experiment (DOE) techniques were used to create a full-factorial test plan that covered all combinations of parameters. The test script involves brake applications at 5, 10, 15, and 20 bar, at both

Passador, Stephen Daniel Austin, Boudreau, Douglas Barret, Capacchione, Christopher James

Effect of Surface Roughness on Tribological and NVH Behaviour of Brake System

2024-01-2732

04/09/2024

Brake assemblies are an essential part of any vehicle, and their effective functioning is critical for the safety and comfort of passengers. The surface roughness of brake components plays a vital role in figuring out their tribological and NVH (Noise, Vibration, and Harshness) behavior. It is essential to understand the impact of surface roughness on brake performance to ensure efficient braking and it has been a topic of interest in the automotive industry. In this study, the influence of surface roughness on the wear, and noise characteristics of a brake assembly has been investigated. The study also provides insights into the relationship between surface roughness, frictional behavior, and NVH performance, which can be used to improve the design and manufacturing of brake assemblies. The brake assembly includes of a disc, caliper, and brake pads, which work together to convert the kinetic energy of the vehicle into heat energy, has been considered in this study. First, the

S, Gurumoorthy, Bhimchand, Naresh, Bourgeau, Alyssa, Bhumireddy, Yugandhar

The Influence of Fundamental Processing Parameters of Ultrasonic Shot Peening on Surface Characteristics of 7B50-T7751 Alloy

2024-01-2681

04/09/2024

Aluminum alloy has become an indispensable part of the automotive industry because of its excellent mechanical properties such as lightweight, high strength, high reliability, maintainability, and low cost. Aluminum alloy is used in automobiles, such as engine blocks, cylinder heads, intake manifolds, brake components, and fuel tanks. Fatigue and fracture are the main reasons for its engineering failure. Surface strengthening techniques, such as ultrasonic shot peening (USP), are often used to improve the fatigue resistance of aluminum alloys. This article expounds on the working principle of USP and elucidates the influence of USP process parameters on the surface characteristics of aluminum alloy. Experimental results observed the effects of USP parameters on surface properties such as surface roughness, microhardness, and surface morphology. The effects of shot peening (SP) diameter, vibration amplitude of ultrasonic vibrating head, and sample placement angle on the surface state of

Adeel, Muhammad, Azeem, Naqash, Xue, Hongqian

Analysis of Low-Frequency Brake Noise for Drum Brakes on Semi-Trailers

2024-01-2895

04/09/2024

A road test on semi-trailers is carried out, and accelerations of some characteristic points on the braking system,axles,and truck body is measured,also brake pressure and noise around the support frame is acquired.The measured data was analyzed to determine the causes of the brake noise, and the mechanism of the noise of the drum brake of semi-trailers during low-speed braking was investigated. The following conclusions are obtained: (1) Brake noise of the drum brake of the semi-trailer at low-frequency is generated from vibrations of the brake shoes, axle, and body, and the vibration frequency is close to 2nd natural frequency of the axle. (2) Brake noise is generated from stick-slip motion between the brake shoes and the brake drum, where the relative motion between the brake drum and the brake shoes is changed alternately with sliding and sticking, resulting in sudden changes in acceleration and shock vibration. A multi-body dynamic model of the semi-trailer is established for

Tang, Hao, Shangguan, Wen-Bin, Kang, Yingzi, Zheng, Jing-Yuan, Lan, Wen-Biao

Measurement and Modeling for Creep Groan of a Drum Brake in Trucks

2024-01-2351

04/09/2024

An experiment is carried out to measure creep groan of a drum brake located in a trailer axle of a truck. The noise nearby the drum brake and accelerations on brake shoes, axle and trailer frame are collected to analyze the occurring conditions and characteristics of the creep groan. A multi-body dynamics model with 1/4 trailer chassis structures is established for analyzing brake component vibrations that generates the creep groan. In the model, the contact force between brake cam and brake shoes, the contact friction characteristics between brake linings and inner circular surface of brake drum, and the properties of chassis structure are included. Dynamic responses of brake shoes, axle and trailer frame during the braking process are estimated using the established model and the responses are compared with the measured results, which validate the model. Three conclusions of measurement and calculation are obtained. (1) The creep groan is usually generated when braking speed is lower

Zheng, Jing-Yuan, Shangguan, Wen-Bin, Tang, Hao, Lan, Wen-biao

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