Investigation of influential factors of a brake corner system to reduce brake torque variation

Abstract

This paper investigates the brake corner system to reduce brake torque variation in the brake judder problem. A numerical model for determining brake torque variation was constructed using the multi-body dynamics model. Using this model, the brake torque variation for a given disc thickness variation was obtained in the time domain. The multi-body dynamics model was verified by a dynamometer test via the comparison of brake torque variation and load distribution patterns of the pad. To reduce the simulation time and cost required to determine factors that influence the reduction in brake torque variation, a simple mathematical model was constructed and used to determine both the brake torque variation and influential factors. The multi-body dynamics model and dynamometer test were modified on the basis of the results of the simple mathematical model and deformed shape of the multi-body dynamics model. These influential factors were verified to reduce the brake torque variation.

Effect of Disc-Pad Contact Modification on the Brake Judder Source Using a Simplified Elasto-Kinematic Model

“…. Previous literature has focused on the sensitivity to stiffness distribution within the caliper system and some coupling with the hydraulic system [2,3,4]. These works suggest that judder sensitivity at the caliper can be reduced by decreasing the effective stiffness of the caliper system, a change which can adversely affect pedal feel.…”

“…Although DTV (ζ(t)) is typically required to produce judder, certain attributes of a disc and caliper system can significantly contribute to . Most mathematical or computational models for brake judder assume a uniform brake disc-pad contact surface [2,3,4]. However, a disc which possesses a wavy braking surface will create a non-uniform contact interface between it and the brake pad.…”

Order domain analysis of speed-dependent friction-induced torque in a brake experiment

“…This low frequency problem is excited by geometric distortions of the brake rotor such as disc thickness variation and lateral run-out. The excitation frequency of the external forcing function is proportional to the vehicle or wheel speed, and the first few orders of geometric disturbance are usually dominant [1][2][3][4][5][6][7]. Jacobsson [1] has discussed plausible causes and effects in a comprehensive pre-2003 literature review.…”

“…Leslie [6] describes a detailed caliper model where the torque amplitude is related to the stiffness of the brake pads, caliper body, and hydraulic system, though amplitude growth is not calculated. Kim et al [7] use the multi-body dynamics approach (via a commercial code) to suggest that a lower stiffness in the normal direction of the brake rotor and a higher stiffness in the rotational direction should lead to lower T(t) amplitudes. Overall, the speed-dependent behavior of T(t) is not well understood, and thus physical mechanisms leading to this response are experimentally, analytically, and numerically examined in this article.…”

Brake judder analysis using a car rigid–flexible coupling model

“…Hussain et al created a two-dimensional and a three-dimensional commercial vehicle model, and investigated the transmission of vibration in the form of judder from the brake of a commercial vehicle to the cab and driver [8]. Kim et al [9] built a multibody system dynamics model of a brake system and investigated the influence factors of the brake cornering system to reduce brake torque variation. Meyer analysed the excitation and transmission mechanism of brake judder using the coupled brake, chassis, and steering system [10].…”