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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Optimization of ceramic composite material disk brakes design for automotive applications: A study on lightweight structure, efficiency, and mechanical durability</title>
      <link>https://trid.trb.org/View/2701155</link>
      <description><![CDATA[This research aims to investigate the utilization of composite materials in the vehicle industry by manufacturing the disk brakes. The vehicle industry persistently searches for augmenting efficiency through the integration of innovative technologies, enhancing performance and minimizing the cost to increase riding safety and comfort. In this work the strong adhesive epoxy is employed as a binder matrix to fabricate disk brakes. The reinforcing agents include high strength, high hardness, heat resistance, and high thermal conductivity ceramic powders, such as alumina and zinc oxide. The hybrid composite material characteristics were assessed via experimental tests, which included tensile, hardness, impact, wear, and friction tests. A finite element analysis via ANSYS 2023 R² software and solid work 22 were used for further scrutiny of the experimental tests. The finite element model of the composite sample was used to determine the optimal mechanical properties. The investigation involves the analysis of von-Misses stress, total deformation, equivalent elastic strain, and strain energy. A comparative analysis was performed on the results obtained with a disk brake made of structural steel and gray cast iron as traditional materials.]]></description>
      <pubDate>Wed, 20 May 2026 09:10:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2701155</guid>
    </item>
    <item>
      <title>Improving the Efficiency of Using an Electric Scooter in Urban Electromobility</title>
      <link>https://trid.trb.org/View/2686205</link>
      <description><![CDATA[The popularity of electric scooters as an individual means of transport results from their availability in the urban sharing system, ease of movement in the city and reduction of driving time compared to other means of passenger transport. The user can choose from a whole range of vehicles with different driving range and equipment with elements increasing the functionality of using the scooter. The article presents a proposal for changes to the design of a typical electric scooter. The main objective of the work is the engineering design of suspension and braking systems, in particular the swing arm suspension of the front and rear wheels and an additional disc brake. Increasing the diameter of the wheels and equipping it with a front and rear suspension system allowed for the reduction of vibrations and shocks transferred to the vehicle when driving on uneven surfaces. The results of analytical calculations confirming the positive effects of the introduced modifications were included. Adding a disc brake allowed for shortening the braking distance from 13.7 to 8.9 m, which has a positive effect on driving safety. A Finite Element Method (FEM) strength analysis was also performed, the results of which confirm the correctness of the new design. The modernized design improved the ride comfort and safety of using the electric scooter.]]></description>
      <pubDate>Wed, 13 May 2026 17:01:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2686205</guid>
    </item>
    <item>
      <title>The influence of air parameters on the indicators of air movement in the air pipe of a brake test bench</title>
      <link>https://trid.trb.org/View/2666137</link>
      <description><![CDATA[The article describes the features of computer modelling of air flow in the air pipe of a brake test bench. The study was conducted in ANSYS, in which FLOW-SIMULATION was implemented. The influence of air parameters on the indicators of air movement in the air pipe of a brake test bench has been determined. It was found that the controlled indicators are directly proportional to the air temperature. The results of the calculations will help reproduce the actual braking conditions of a railway car in the laboratory and can be a useful experience in the development of modern disc brakes for rolling stock with improved characteristics.]]></description>
      <pubDate>Mon, 23 Mar 2026 15:15:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2666137</guid>
    </item>
    <item>
      <title>Further Investigation of Disc Pad Compression Deformation during ISO Compressibility and Dynamic Modulus Measurements under Relatively Low Pressures</title>
      <link>https://trid.trb.org/View/2600498</link>
      <description><![CDATA[In an earlier publication, it was reported that the pad compressibility measured under 160 bars on NAO formulas keeps decreasing with increasing number of repeated measurements due to unrecoverable residual deformation of the friction material combined with increasing moisture adsorption, which increases the hardness of the friction material. This current investigation was undertaken to find out if this same phenomenon occurs for NAOs under a low pressure of 100 bars during compressibility measurements and under 700N during dynamic modulus measurements. In all cases, it is found that the same phenomenon occurs, meaning that friction materials become permanently compressed without full recovery, making them harder to compress and raising up the modulus. The dynamic modulus of friction material attached to a backplate is found to be lower as compared with the friction material without the backplate, which is caused by more rapid moisture adsorption of friction material pads without a backplate. As pad properties are continuously changing under pressure at temperature during usage, compressibilities and dynamic moduli measured for the initial quality must not be used for predicting brake performance/NVH – an important issue for AI databases.]]></description>
      <pubDate>Tue, 16 Sep 2025 11:05:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2600498</guid>
    </item>
    <item>
      <title>The Analysis and Optimization Approach for Solving the
          Thermomechanical Issues of Automotive Disk Brake</title>
      <link>https://trid.trb.org/View/2595158</link>
      <description><![CDATA[The thermal characteristics of brakes significantly influence the braking                     performance of passenger vehicles. During braking, most of the vehicle’s kinetic                     energy is converted into internal energy in the brake disk through friction,                     leading to complex coupled thermomechanical issues. This article focuses on the                     analysis of a disk brake from a specific vehicle model. Using STAR-CCM+, a                     virtual disk brake bench simulation model was established. Based on the                     multi-timescale and multi-field coupled simulation method, the analysis of the                     brake disk temperature and field distributions under cyclic braking conditions                     was carried out. Subsequently, this work investigated the effects of factors                     such as thermal conduction, thermal radiation, and the shape of ventilation ribs                     on the heat generation and dissipation characteristics of the brake disk.                     Finally, a thermal deformation simulation and optimization method was developed                     using STAR-CCM+, ABAQUS, and ALTAIR OPTISTRUCT software. In comparison with the                     test measurements, the accuracy of the thermal deformation simulation for the                     brake disk reached 94.5%, and the optimized brake disk’s thermal deformation was                     further reduced by 36.1%. This work provides a design verification method for                     brake disk optimization.]]></description>
      <pubDate>Mon, 08 Sep 2025 12:23:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2595158</guid>
    </item>
    <item>
      <title>Methodology for Fast-Running, Time-Resolved Simulation of Non-Exhaust Particle Emissions from Brake Wear Abrasion</title>
      <link>https://trid.trb.org/View/2571698</link>
      <description><![CDATA[Non-exhaust particle emissions, particularly those generated by brake wear, are a significant source of fine particulate matter in urban environments. These emissions contribute to air pollution and pose serious health risks, particularly in densely populated areas. While vehicle exhaust emissions have been extensively studied and regulated, the contribution of non-exhaust sources, including brake wear, remains a critical factor in air quality management. This paper presents a novel methodology for fast-running, time-resolved simulation of non-exhaust particle emissions, specifically those from brake wear abrasion. A 3D CFD model computes the turbulent flow field around the disc brake. The resulting information on the convective air cooling is applied as boundary conditions on a 3D thermal model. This thermal simulation setup is compared and verified with experimental data from literature. The 3D numerical models produce data and boundary conditions for an efficient 1D numerical approach that models the dynamic processes of brake temperature development. The average temperature deviation between the 3D and 1D simulation is less than ΔT1D,3D=1.5 K in the validated section of the WLTP brake. The 1D simulation is coupled with data-based models of brake-induced non-exhaust emissions. This combination enables the generation of detailed, time-resolved emission profiles that account for the variability in driving conditions, such as speed and braking intensity. The methodology further explores and models the key impact factors influencing brake-induced particulate emissions, including material properties, brake system design, and environmental conditions. By providing time-resolved output, the methodology offers a more precise analysis of emission-relevant events in real-world driving scenarios, compared to traditional emission factor approaches, which typically assume constant emission rates. This approach captures the temporal variability of particle emissions during different driving phases. The speed and computational efficiency of the method make it suitable for large-scale simulations, while maintaining high accuracy when validated against experimental data.]]></description>
      <pubDate>Tue, 08 Jul 2025 10:41:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2571698</guid>
    </item>
    <item>
      <title>Modelling and control of electromechanical disc brake for heavy-duty vehicles</title>
      <link>https://trid.trb.org/View/2539845</link>
      <description><![CDATA[This paper proposes a validated procedure that can be used for development stage of model-based controller for heavy-duty electromechanical disc brakes. Firstly, system dynamics model of a single piston electromechanical disc brake is constructed in Matlab/Simulink environment in consideration of nonlinear friction model. To ensure the accuracy of system dynamics model, open loop measurements (clamping force, motor angle and motor current) are conducted on a prototype of single piston electromechanical disc brake. Experimental data is used for the determination of system variables. The predicted outputs are verified by comparison of experimental measurement results. For the control purpose of electromechanical brake, a multi-stage closed loop architecture is introduced. To regulate clamping force, PID and sliding mode controllers are developed in Matlab/Simulink in consideration of braking performance requirements for heavy-duty vehicles. For management of running clearance between brake disc and pad, PID position controller is developed in simulation environment. Those controller parameters obtained in the simulation process are introduced to the control hardware. After that closed loop clamping force and position measurements are conducted. When the rise time values of both clamping force controllers are compared, it is seen that sliding mode controller can reach to the settling point faster than PID controller. As for the position controller, the rise time requirement has been achieved by the designed PID controller. The switching process of force and position controllers are implemented and functional closed loop measurements are conducted for different reference input signals. It is seen from the results that the rise time requirement for position controller has been achieved. The system response of clamping force parameter is considerably stable.]]></description>
      <pubDate>Tue, 27 May 2025 09:33:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2539845</guid>
    </item>
    <item>
      <title>Brake Noise CAE Enhancement with the Synergy between Design of Experiments and Machine Learning</title>
      <link>https://trid.trb.org/View/2552222</link>
      <description><![CDATA[The digitalization of industrial systems has led to increased data availability. Machine learning (ML) methodologies are now commonly used for data analysis in industrial contexts. Not all contexts have abundant data; sometimes data collection can be scarce or expensive. Design of Experiments (DOE) is a technique that provides an informative dataset for ML analysis when data are limited. It involves systematically designing experiments to collect relevant data points with regression models.Disc brake noise is a challenging problem in vehicle noise, vibration, and harshness (NVH). Different noise events occur under various operating conditions and across frequencies (1-16 kHz).To enhance computer-aided engineering (CAE) techniques for brake noise, ML is used to generate additional data. Sequential experimentation in DOE aligns well with ML’s ability to continuously learn and improve as more data become available. DOE is applied in CAE to collect data for training ML models. ML helps find patterns in high-dimensional data by modeling relationships between operating conditions and related variables, which are then validated and correlated with CAE results. In summary, combining DOE with ML can address data scarcity and enhance predictive models, especially in complex industrial scenarios like brake noise analysis, and makes it valuable for industrial experiments.]]></description>
      <pubDate>Tue, 13 May 2025 10:11:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/2552222</guid>
    </item>
    <item>
      <title>Evaluation and Prevention of Brake Drum Freezing by Aerodynamic Measures</title>
      <link>https://trid.trb.org/View/2539707</link>
      <description><![CDATA[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 mountings can potentially lead to leaks on the backplate. This study highlights the impact of water/snow ingress on the example of a frozen parking brake during cold climate on-road testing. Through scientific investigation using the state-of-the-art fluorescence method, drum leakages were visualized, and the extent of water ingress was measured. Multiple multiphase CFD simulations supported the design phase of the aerodynamic measures. Subsequently, the vehicle was cooled down to -10 °C to simulate the cold climate test conditions. The frozen parking brake situation could be reproduced with this method, and beneficial aerodynamic and sealing measures were extrapolated to avoid the drum brake from freezing. The tests were conducted in the FKFS Thermal Wind Tunnel, a wind tunnel comprising a two-axle-dynamometer and water irrigation systems with UV illumination.]]></description>
      <pubDate>Tue, 15 Apr 2025 13:56:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2539707</guid>
    </item>
    <item>
      <title>Enhancing Disc Brake Performance: Investigating Squeal Noise, Wear, and the Application of Functionally Graded Materials in Brake Rotors</title>
      <link>https://trid.trb.org/View/2511128</link>
      <description><![CDATA[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 studies evaluate the noise and wear behaviour of disc brake assemblies made with FGMs. The paper also investigates the application of FGMs in brake rotors, highlighting their distinctive properties and the advantages they offer to automotive braking systems. The study underscores the importance of further research and development to fully leverage the benefits of FGMs in enhancing brake system performance.]]></description>
      <pubDate>Tue, 18 Feb 2025 14:58:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2511128</guid>
    </item>
    <item>
      <title>Complex Eigenvalue Analysis for Reducing Low Frequency Brake Squeal</title>
      <link>https://trid.trb.org/View/1787481</link>
      <description><![CDATA[A front disc brake system is used as an example for an investigation of low frequency squeal. Many different modifications to this disc brake system have been proposed and this paper focuses on a solution that reduces the stiffness of the rotor. This is accomplished by a reduction in the Young's modulus of the rotor material. The complex eigenvalue method is used for a detailed analytical study in order to obtain a better understanding of this solution technique. Modal participation factors are calculated to examine the modal coupling mechanism. Parametric studies are also performed to find out the effects of friction coefficient and rotor stiffness. Results show that shifting rotor resonance frequencies may decouple the modal interaction and eliminate dynamic instability, which is in agreement with experimental results.]]></description>
      <pubDate>Wed, 22 Jan 2025 09:33:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1787481</guid>
    </item>
    <item>
      <title>An Analytical Method to Predict Thermal Distortion of a Brake Rotor</title>
      <link>https://trid.trb.org/View/1787405</link>
      <description><![CDATA[The severe thermal distortion of a brake rotor can affect important brake system characteristics such as the system response and brake judder propensity. This paper will propose a technique to determine the thermal distortion under transient or steady state conditions. The technique involves utilizing a PC-based computer program to calculate the necessary thermal parameters and apply the results as input to a finite element-based thermal stress analysis. This unique approach provides a reliable methodology to determine the heat input and cooling characteristics of a given brake system in addition to resultant distortion and stress components within the brake rotor. Analysis results are also compared to measured temperature and distortion data.]]></description>
      <pubDate>Mon, 23 Dec 2024 10:40:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1787405</guid>
    </item>
    <item>
      <title>Research on service behaviour of brake pad fastener snap ring during high-speed train braking process</title>
      <link>https://trid.trb.org/View/2437623</link>
      <description><![CDATA[Disc brake performance is an important guarantee for the safe operation of high-speed trains. Brake pad fastener snap rings may fail during train braking, causing the friction body to fall off, which is a serious threat to the safety of train operation. This article establishes a finite element model of brake pads/discs taking into account the thermal-mechanical coupling field in the braking process. The temperature distribution of the brake disc surface, the displacement and stress results of the snap rings at different positions are investigated. The results show that the temperature of the brake disc rises and then falls during braking, and the surface temperature of the brake disc is spread in the form of an annular band. The highest displacement and stress variations are found in the snap ring group around the speed entrance area and the inner side of the brake pad. In the x and z directions, the average displacement changes are 0.1967 and 0.1233 mm, respectively. The average changes in contact stress and internal stress are 9.8 and 15.5 MPa. The results of the service behaviour of the snap ring provide a basis for the study of snap ring failure.]]></description>
      <pubDate>Thu, 05 Dec 2024 09:38:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2437623</guid>
    </item>
    <item>
      <title>Environmental Problems Associated with Vehicle Braking and Their Solutions</title>
      <link>https://trid.trb.org/View/2407146</link>
      <description><![CDATA[The article considers the problem of the reliability of semitrailer truck. The results of processing statistical data on the workability of semitrailer trucks due to a malfunction of the brake system are presented. Data processing was carried out according to the operating data of the world’s leading companies VOLVO and MERCEDES - BENZ (truck), as well as Schmitz, Kögel, Krone (semitrailer). The results of processing the data on the brake pads wear of the truck’s disc brakes are presented. The mass of friction material resulting from the wear of brake pads, calculated per millimeter of worn-out pads and kilometer run of a semitrailer truck, has been determined. An expert assessment and ranking of factors affecting the wear of the friction pair “brake dick - pad” of the road train was carried out. A technical solution for the abrasive particles capture that occurs during braking is proposed. This system can be used on all vehicles with disc brakes.]]></description>
      <pubDate>Wed, 20 Nov 2024 13:08:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/2407146</guid>
    </item>
    <item>
      <title>Study on the influence of running parameters on the temperature field of disc brake on long downhill road</title>
      <link>https://trid.trb.org/View/2437492</link>
      <description><![CDATA[The braking system of the vehicle is liable to fail due to the high temperature of frequent braking in the downhill road. This paper analyzes the influence of the main operating parameters of the vehicle on the maximum temperature of the brake disc surface. Firstly, the mechanical characteristics of the vehicle on the long downhill road are analysed, and the Finite Element Model of the brake disc/friction plate is established; Secondly, the effects of gradient, vehicle weight, brake speed threshold and brake pressure on the braking cycle and disc brake temperature field on long downhill roads are studied. The results show that when the gradient increases from 3° to 9°, the maximum temperature of the brake disc increases by 41.6%, while when the vehicle weight increases from 4 to 7 tons, the brake disc temperature only increases by 16.7%. For the braking speed threshold and braking force that the driver can control, selecting a smaller braking force and a lower braking speed threshold can better inhibit the temperature rise of the brake disc. Finally, the effectiveness of the simulation method is verified by the real vehicle test. It is found that the average measured temperature is 9.2%–11.8% lower than the simulated average temperature. It is considered that the modified temperature value can be obtained by reducing the maximum temperature of the simulation model by 5%–6%.]]></description>
      <pubDate>Tue, 29 Oct 2024 15:29:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2437492</guid>
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