Search Results

Nowadays, the sever customer targets in term of squeal require an increasing number of different tests. This paper addresses how to develop a new test bench procedure which helps to fulfill this new target with more efficiency. With a single standard test procedure, we want to: find out a maximum number of frequencies in a minimum number of stops, improve road correlation with adapted braking conditions including detection of the low pressure risks, improve the stability of the results to get more valuable test comparison. A statistical analysis performed over three years of chassis dyno matrix test shows that noise risks in low pressures conditions are usually not well estimated in standard procedures. Indeed, pressure, speed and temperature steps are arbitrarily constant in most standard procedures and do not take into account the non-linear influence of these parameters on the noise generation.

This paper discusses the analysis and measurement of the dynamic centre of pressure of a brake pad during a normal braking event. The technique is unique in its design and implementation. The process is progressive whereby the interface static measurements are first taken and then dynamic testing is carried out under braking. Two different measurement systems are considered during the analysis with one used to measure the center of pressure. Both the in-board and out-board pads are measured for wear but the piston pad was selected for pressure measurements. Validation of the spragging process is undertaken on both test rigs and vehicle trials. Pad wear measurements complement the collective information. The results show the position of the centre of pressure to vary considerably during a braking event, both radially and axially along the pad.