Friction Materials and Brake pads

An important factor for brake noise reduction is tuning the resonance frequencies of the main components such as disc, caliper, bracket and brake pad, in order to harmonize them. 

Brake pads can show a significant spread in the resonance frequencies linked to variations over the entire production process.  Variations can be linked to friction material mixtures and inhomogeneity, the pressure and filling degree during the compacting phase, the location in the oven and the time/temperature profile during the baking process.

Given the importance of natural frequencies, the SAE (Society of Automotive Engineers) documented in the SAE J2598 a standardized and repeatable method for performing natural frequency and damping measurements on a disc brake pad.  According to this procedure, the evaluation of the first three natural frequencies is described as the basis for a quality indicator by measuring these frequencies and their respective damping.

GrindoSonic MK7 technology allows the evaluation of 4 frequencies and their respective damping.  Additionally by using the “Brake Pad” application of the system, it becomes a universal instrument for industrial Quality Control and Process Engineering.

  • The entire spectrum can be inspected and visualized
  • Enables to discriminate between good brake pads as per the OEM’s specifications
  • Quantification of the damping enables selection based on the presence of cracks in materials (cracks tend to absorb higher-frequency vibrations and show increased damping)
  • A performance indicator can be determined after identification of a spectral region showing significant difference

With the GrindoSonic MK7 system the “mechanico-elastic” behaviour, say the fingerprint of your brake pad can be measured at the end of the production line. The lower frequencies give an indication of porosity, surface hardness, dimensions whereas the damping indicates the presence of (micro)cracks.

GrinoSonic’s manually operated MK7 is a good tool for analysing and optimizing the process parameters (Quality and Process Engineering).  When tuning a single parameter in the production process, its impact can be measured on the output of the line.

Additionally, the GrindoSonic MK7 technology automatically calculates material characteristics such as  E-, G-modulus and Poisson’s ratio on different object shapes.

It goes without saying that, given its easy, fast and reliable measurement method that complies with the SAE standard, GrindoSonic systems are widely and globally used in the brake pad industry.