Browse Publications Technical Papers 2019-01-2111

Squeal Noise Improvement by High Damping & High Stiffness under Layer Material 2019-01-2111

The purpose of this research is to clarify how damping characteristics of Under Layer (hereafter “UL”) material in the brake pads (hereafter “PAD”) influences brake squeal noise performance. In this study, UL material structure and dynamic viscoelasticity, for two different types of UL formulations are investigated. In addition, PAD damping ratio and squeal noise performance for multiple UL formulations are verified. As a result, the raw material orientation is determined based on manufacturing method, and it causes the UL material’s anisotropic properties. Dynamic viscoelasticity are dependent on the direction in which they are measured. In particular, the loss modulus, which is the damping element of dynamic viscoelasticity, is higher in the direction of the raw material orientation for the high damping and high stiffness UL formulation. In addition, it was confirmed that this loss modulus in the direction of the raw material orientation is effective for bending vibration. In the verification, the study focuses on the PAD damping ratio and squeal noise performance in the 1st bending vibration of the PAD. It is clarified that the PAD damping ratio increased as the loss modulus increases, which leads to improve squeal noise. In conclusion, this research proves that the high damping and high stiffness UL material is effective for squeal noise improvement.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

In-Plane Vibration Investigations of a Noisy Twin Calliper Disc Brake


View Details


Study of Brake Squeal - Classification for Vibration Modes of Mounting Bracket


View Details


A Study on Trigger of Disc Brake Squeal Generation


View Details