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Shim bond coverage analysis is a common practice in brake and pad manufacturing during brake pad development. This analysis is used to assess the quality of a shim bond and quantify it in case of any quality or de-bond issues during production and warranty returns. Currently, the analysis is carried out manually in the industry using a 1:1 template printed on tracing paper, which is placed on the deboned shim to identify bad bonded regions. The bond coverage is then calculated manually based on the data obtained from the template, which is a time-consuming process taking around 15 minutes per pad/shim analysis. To minimize manual work and increase accuracy, artificial intelligence is being used to estimate the shim bonding quality and coverage. The idea is to feed the deboned shim and pad picture to the model and predict the following: Whether the bond coverage is good or bad. Identify the good/bad and unnecessary regions on the shim/pad for bond coverage analysis.

The rising popularity of EVs has led to a resurgence of interest in drum brakes. Drum brakes benefit from less complex mechanical design, have no residual brake drag, and the enclosed design is less susceptible to corrosion and debris emission. For the commercial EVs, the elimination of engine noise makes brake noise a major contributor to vehicle noise. With the renewed interest in drum brakes, there is an increased need for property data for NVH simulations to optimize noise performance. Similar to disc brakes, the modeling of drum brake performance requires a complete set of friction material engineering properties determined over the pre-loads and temperatures encountered in brake applications. Results are presented for eight different drum brake formulations and platforms. The measurement approach and data analysis parallels that used for the elastic property measurements of disc pad friction materials, SAE J2725.

The Simulated Los Angeles City Traffic (SLACT) test is a well-established dynamometer test procedure used to evaluate brake noise and lining wear performance under a typical US city driving conditions. This procedure is based on a vehicle test conducted on the roads of Los Angeles, California. Unlike ICE vehicles, in electric vehicles regenerative brakes do a significant amount of the work to stop the vehicle, resulting in less work required from the foundation brakes. This means that the life of a brake pad could significantly increase in electric vehicles. It is possible then to reduce the thickness of the brake pad to improve packaging and cost. However, in situations where regenerative braking is disabled due to a failure or low battery charge level, all the work must be done by the foundation brake with no support from the regenerative braking. Hence, it is crucial to select the optimal brake pad thickness for such scenarios.

The automotive industry continues to focus heavily on new electrified mobility strategies. Whether this electrified mobility consists of battery electric vehicles or electrified brake boost systems, there is a level of system sensitivity which presents new challenges throughout the industry during development of a new product. Most specifically in brake system development, much of the critical performance targets that have come along with electrification are cascaded down to the vehicle corner and its component performance. These corner level requirements have transformed to be more stringent in order to improve the overall system efficiency. It is important that the factors which lead to less than desirable performance are identified and understood. Some of the factors that influence the brake system corner performance are driven by multiple components, and this paper will go into identifying & explaining the following.

New technologies, such as electrified powertrain and autonomous driving solutions, are transforming the automotive industry in such a way that achieving vehicle level performance requirements demands an increasingly intensive and detailed system integration exercise. Validation of the braking system, critical to any vehicle level project, must evolve so that the ever-increasing requirements cascade is answered in a way that ensures the highest level of safety and performance as the industry moves toward a new frontier of features. To support this evolution of integration methodology, critical-to-performance components, such as brake pads, must undergo a transformation in how performance metrics are characterized, communicated, and documented.

Friction material manufacturing is a complex process where numerous raw materials are mixed, pressed, and cured to make brake pads. It is important to have a consistent manufacturing process that can produce a brake pad that satisfies the vehicle braking requirements. A basic and critical requirement for any brake pad is structural integrity with no internal cracks. In this work a series of processing changes were made to intentionally produce internal cracks in the friction material. Various pad crack detection methods were studied, and their advantages and disadvantages are discussed in detail. One of the crack detection methods used an ultrasonic measuring instrument which gives objective data in the form of calculated modulus of elasticity and signal loss. The details of the machine and how the measurements are obtained are discussed. The modulus calculation is also described.

Friction material back plate design, manufacturing and consistent quality are some of the key attributes for better brake performance. Historically, the auto industry’s focus on back plate quality has been limited to drawing dimensions. Recently, vehicle manufacturers across the globe are tightening caliper performance criteria to achieve near zero drag for fuel consumption regulations and improved NVH to attract end customers. To meet these new stringent requirements, friction and back plate suppliers need to focus, in more detail, on how to improve the backing plate quality and better understand the interface characteristics of back plate/pad assembly to caliper performance. While many key characteristics of the back plate were identified in past assembly design process, there has been vague understanding to connect with caliper performance, thus, the definition of back plate quality has been limited to basic dimensional measurement.

It is always a challenging task for the braking industry to maintain consistent friction material behavior during brake system development. Lack of consistency in friction behavior causes significant disruptions in efforts to integrate friction material with the foundation brake system. This is especially true when new friction formulations and/or manufacturing processes are introduced during an application program. Furthermore, every new program has new requirements that introduce new challenges and issues to the brake and friction manufacturers. As issues arise during the Application development, engineers devise countermeasures that often entail new engineering techniques and methods. Sometimes, such countermeasures amount to inventions to cover the inadequacy of lining behavior during brake integration.