Investigation of Brake-judder through Caliper Vibrations due to the Effects of Friction Pad Properties, Disc Thickness Variation and Brake Torque Variation using a Dynamometer

There is a budding demand in the automotive industry for discovering the causes of brake judder and numerous mathematical models for analysis and simulation have been established. Since most of the data and knowledge are hidden within automobile manufacturers, it is still a mystery to unravel and get a clear picture. Judder was reported on the field during vehicle testing with a subjective assessment of Pad A (highlighted in table 1). The aim was to investigate the problem at the brake component by altering pad grades since it was within the scope of the study. Therefore, to save the time of running the vehicles and keeping the least variables from the 4M (Material, Method, Machine, Man), 8 combinations of friction pads were taken on an inertia brake dynamometer and deals with judder arising from the disk brake assembly only. This paper provides a novel approach by running various permutations and combinations of friction pads and interlinking caliper vibrations with the factors such as Brake torque variation (BTV), disc thickness variation (DTV), and friction pad properties by DOE (Design of experiment) analysis. It also provides some insight on the causes, types of brake judder and further gives quantifiable results which determine the bandwidth of the factors based on the experimental results. The paper is structured as follows: the introduction and causes to judder are covered in section 1. Materials and methodology in section 2, Results in section 3, and conclusion in section 4.