Forced stick-slip oscillations allow the measurement of the friction force: Application to paper materials

• We examine changes in friction coefficients with the experimental protocol.
• We built an experimental device dedicated to the measurement of friction.
• The proposed method gives lower dispersions and better accuracies than standard methods.

Different methods for measuring the friction forces are investigated in this paper. We consider the paper-on-paper contact as an example of application. We first underline several drawbacks for the two main standard methods, namely the inclined and horizontal plane methods. In particular, the horizontal plane test method often involves stick-slip oscillations that make the measurement of the friction force impossible. We then propose a method for characterizing these oscillations and removing their influence on the friction force measurement. The comparison of the proposed method to standards suggests that our proposed method delivers measurements that are much more accurate and repeatable. We finally discuss the validity of averaging the friction force measured during the sliding movement.