Heavy Duty Automotive Drum Brake Squeal Analysis Using the Finite Element Method

Parametric analysis on temperature influence on brake squeal generation in a single-seater off-road vehicle’s disc brake

“…Whether we are traveling on a bicycle, a wagon, or the fastest car, safety relies upon the brakes, which use friction to stop and dissipate the kinetic energy generated into heat and noise vibrations. [1][2][3][4][5] Disc brakes have become the most well-known braking system used in modern cars due to their superior heat dispersion and resistance to fade compared to drum brakes. [6][7][8] However, even disc brakes are not immune to the problem of noise induced by friction, such as brake squeal.…”

“…This noise, also known as whining, occurs when the brake pad material comes in contact with the disc material. Engineers and researchers have defined brake squeal into many categories, [2][3][4]9 with squeal being the most significant due to its frictioninduced nature. Squeal is an auto-excited noise that creates self-sustained vibrations for a short period.…”

“…[8][9][10]12 The most well know brakes used in nowadays cars are the disc brakes, for its better heat dispersion and resist to fade than drum brakes, [6][7][8] however, that does not exclude them from the noise induced problem, the brake squeal. This noise, or whining, as mentioned before, occurs when the pad material comes in contact with the disc material, being defined by engineers and researchers in many categories, [2][3][4]9 but, squeal being the most important, as it is a friction-induced noise, auto-excited, having self-sustained vibrations for a short period, 10,11 having two definitions, low-frequency, with spectrum bands varying from 1 to 7 kHz, and high frequency squeal, happening between 5 to 20 kHz. 5,8,11,12 Currently, there are three explanations for the occurrence of brake squeal: stick slip, sprag slip, and mode-coupling.…”

“…[2][3][4]12,13 The stick slip explanation is primarily based on the assumption that the coefficient of friction between the brake pad and the brake disc decreases with increasing sliding speed between them, systems in which the coefficient of friction decays with increasing speed may have negative damping factors and hence unstable oscillation modes, leading to brake squeal. [2][3][4]11 The sprag slip explanation arises from the geometrical deformation of the brake components, mainly the friction component (the pads for disc brakes and lining for drum brakes), resulting in the normal and tangential force variation, making the system prone to brake squeal. [2][3][4] The third explanation, mode-coupling, occurs when the vibration modes of the brake components become coincident.…”

Friction-induced noise in drum brakes: finite-element modeling and experiments with special focus on damping

“…Usually complex eigenvalue analysis (CEA) of high-dimensional FE disk brake models possessing a million or more degrees of freedom are carried out, e.g. [19,46]. These analyses are often run in the absence of damping, see [4] or focusing on shifting natural frequencies of brake components rather than increasing damping, like the altering of the chemical composition of the casting material [23].…”