document: The lateral force, Q, is measured and recorded throughout the entire test by a piezoelectric load cell which is connected to the quasi-stationary LSMB. The LSMB is mounted on flexures which provide flexibility in the horizontal direction so that the majority of the lateral force is transmitted though the much stiffer load path which contains the load cell as shown in Fig. 2. Both displacement and load sensors have been calibrated (both externally and in-situ) in static conditions. The load and displacement signals are sampled at a rate of two hundred measurements per fretting cycle at all fretting frequencies, with these data being used to generate fretting loops. The loops were used to derive the contact slip amplitude and the energy coefficient of friction in each cycle according to the method suggested by Fouvry et al. [17]. Average values for these were calculated for each test (the average coefficient of friction included values associated with the initial transients in the tests as suggested by Hirsch and Neu [18]).
extractive_keyphrases: displacement and load sensors flexures load cell lsmb
abstractive_keyphrases: fretting loops. lateral force, q, is measured and recorded piezoelectric load cell