Experimental study on the impact of variations in the friction material properties on the vibration behaviour of brake pads

Document Type : H. Ahmadian Prize


1 Automotive Research Centre, Department of Mechanical and Energy Systems Engineering, University of Bradford, Bradford, UK

2 Assistant Professor, School of Automotive Engineering, Iran University of Science & Technology, Tehran, Iran


Brake noise is often caused by the coupling of the natural frequencies of the disc and pad. To prevent this, it is important to control the natural frequencies of these components, hence, the dispersion of natural frequency values is a critical factor in brake noise determination. This paper examines how the brake pad's natural frequencies and mode shapes are affected by its friction material properties, such as Poisson's ratio, Young's modulus, and shear modulus in different directions. Two brake pad designs from Land Rover are modelled and analysed using finite element analysis (FEA) and experimental modal analysis (EMA). A machine learning algorithm based on multiple-features linear regression is used to identify the main friction material parameters and their relationship to the natural frequencies. The results show that increasing the transverse Young's modulus or decreasing the longitudinal Young's modulus, shear modulus, or Poisson's ratio in all directions can increase the natural frequencies. Consequently, the paper suggests that Poisson's ratio and transverse Young's modulus should be considered when selecting friction compounds for brake pads.


  • Friction material properties are found affecting brake pad natural frequencies and vibration modes.
  • Transverse Young's modulus is found having the greatest impact on natural frequency dispersion.
  • Poisson's ratio and transverse Young's modulus are found key factors for brake noise prevention.
  • Machine learning algorithm successfully identified friction material parameters.
  • •  Principal findings are applicable to any brake pad design regardless of aspect ratios and geometries


Main Subjects

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