A Systems Approach to Eliminating Squeal in a Drum Brake

Proceedings of the Institution of Mechanical Engineers, Part L:

et al. 2021

The method presented in this work intends to analyze drum brake design parameters of a light duty automotive drum brake system. The main objective of this work is to correlate brake materials and unstability parameters to identify which condition will effectively reduce squeal propensity. The methodology involves (a) the finite-element method of the brake components, namely, drum, shoes, and frictional linings, (b) static calculations to get a pre-stress state around which (c) is computed the complex eigenvalues of the system. Hence, positive real parts indicate dynamic instabilities which are explored by varying parameters, namely, the modulus of elasticity of the materials and the friction coefficient at the contact of the shoes with the drum. According to calculations, it was observed that there exist a given range of values for Young’s modulus and friction coefficient that are favorable to reduce drum brake squeal occurrence. In addition, the method proposed delivered results that match with brake squeal literature.

Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Light duty automotive drum brake squeal analysis using the finite-element method

Proceedings of the Institution of Mechanical Engineers, Part L:

et al. 2021

“…This phenomenon can even occur if the friction coefficient is constant 9 and is frequently pointed as the main cause of brake squeal. [9][10][11][12] The high warranty cost and noise pollution on urban areas prompted several research studies about brake squeal. 13 They indicate that squeal is a complex issue with several causes.…”

Section: Introductionmentioning

confidence: 99%

Automotive simplex and duplex drum brake squeal analysis using the finite element method

Noise & Vibration Worldwide

et al. 2022

Despite the fact that disk brakes are used on almost entire mass produced vehicle, drum brakes are still applied on light-, medium-, and heavy-duty vehicles. However, both exhibit a high level of brake noises in which squeal is the most uncomfortable and one of the reasons behind high warranty costs that concern the automotive industry. Hence, the development of prediction methods and models of brake noise have prompted significant efforts. This study intends to analyze two types of drum brakes of a commercial automotive application. Their parametric finite element model comprises drum, shoes, and frictional linings and are submitted to a computational process that includes static calculations of the system under the brake forces to get a pre-stress state around which is computed the complex eigenvalues of the system which characterize their stability. These calculations indicate the unstable frequencies of the entire system. After the design of experiments (DOE) process, the influence of drum brake parameters on system stability can be seen. The friction coefficient and Young’s modulus presented a strong correlation with squeal incidence. At the end is presented a comparison and the optimal material parameters to decrease squeal noise occurrence of these brakes.

“…Behind all these squeal causes and mechanisms are the metallurgical characteristics of the drum brake components, as Young modulus and friction coefficient. 8,19,[21][22][23][24][25][26] Despite the fact that drum brakes are getting obsolete, the disc brake costs are still greater than that. 19 In addition, the drum brake still fits very well in heavy duty vehicles, owing to its bigger selfenforcement effect, high brake power and well suitable for parking device.…”

Section: Introductionmentioning

confidence: 99%

Light duty automotive duplex drum brake squeal analysis using the finite element method

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2021

The brake system creation is an important achievement for automotive production. However there is a secondary response of this system, its noise emission. Brake noise researches started in 1920’s and since then several causes were identified. In addition, many kinds of noises, their frequency range and characteristics were detected. Between these, the squeal is the noise that most concerns the automotive industry by reason of high warranty costs and environmental impact. The squeal noise occurs as a result of three mechanisms that are the stick-slip, the sprag-slip and the modal coupling and these are connected to material parameters of the brake components. This paper proposes a correlation between material and stability parameters of a light duty automotive duplex drum brake to indicate the influence of this on brake squeal. The results suggest that friction coefficient is the most influential parameter and its restrain does make possible to maintain squeal level under emissions regulations.