Assessment of fiber contribution to friction material performance using grey relational analysis (GRA)

Design of friction material composition is a multicriteria optimization problem. The role of fibers in controlling tribo-performance, in particular, is multifunctional. The present article deals with the assessment of fiber contribution to the performance of friction materials based on various possible combinations of organic fibers (Aramid and PAN) and rock fibers (basalt and lapinus). The performance of the materials is evaluated on a Krauss friction tester. The various performance criteria selected for the analysis are friction fade, friction recovery, performance friction, difference between the maxima and the minima in the coefficient of friction, temperature rise of the disc, and wear. The criteria are normalized to conform to the smaller-the-better performance norm correspondingly to their respective performance defining attributes (PDAs). The degree of influence that the fiber combination factors exert on the overall performance is studied by investigating the geometrical correlation between them using grey relational analyzing (GRA). By analyzing the grey relational grade matrix, the most influential fiber combinations with regard to an objective property can be picked. The influence of the individual PDAS on the overall performance is studied. This is based on the correlation between the fiber combinations and their corresponding PDAs. Further, the GRA has enabled to speculate the performance of grey friction materials (based on fiber combinations, which are not evaluated within the context of the present article) in compliance with the existing set of incomplete data.