From Prototype to Production - The Practical Nature of Brake Squeal Noise

Brake squeal noise continues to be a concern within the brake industry. Today, brakes need to perform squeal-free in increasing combinations of operating and environmental conditions. Such requirements, together with component variations arising from developmental process changes from prototype to production, make development of squeal-free brake systems a real challenge within the brake NVH community.

This paper presents a real-world example of the challenges proposed to brake NVH engineers during the noise development of a brake system.

Using the example of a cast iron front caliper, this paper will highlight the sensitivity of brake squeal noise to the following parameters:

• Rotor natural frequency, geometry, and material composition
• Pad chamfer size and angle
• Ambient temperature and humidity
• Test duty cycle

The sensitivity of brake squeal noise is presented for a matrix of variants of environmental/operating conditions and component parameters in conjunction with analyses from a parametric FEA study on the brake system. The effects of each and how they were dealt with during the development phase are discussed, and the importance of process control of brake pads and rotors from prototype to start of production (SOP) in order to ensure a robust squeal noise solution is demonstrated.