Friction coefficient definition in compression-fit couplings applying the DOE method

The fundamental goal of this work is to define a generalized methodology which is useful to calculate the starting friction coefficient µll in the fork-pin compression fit couplings of front motorbike suspensions. The starting friction coefficient µll for these applications was obtained applying the Design of Experiment methodology on several specimens and performing some Finite Element Method analyses in combination with a mathematical model. Couplings are different both for the material of the elements in contact and for the coupling surfaces condition. The possible combinations investigated are: the fork in aluminium and the pin in steel and both the fork and the pin in aluminium. The second goal of this work is to update, applying the µll mathematical models, an innovative software (Fork Design©), realized by the authors in Visual Basic® programming language, which is useful to perform the design and the verification of the fork-pin couplings of front motorbike suspensions, differentiated by the geometry (that means by the stiffness of the fork) and by the materials of the coupled parts.