VIBRACINIAIS SIGNALAIS GRINDŽIAMAS TEKINAMO PAVIRŠIAUS ŠIURKŠTUMO VERTINIMAS: METODIKOS ADAPTACIJA IR TAIKYMO RIBOS TEKINANT ALIUMINIO LYDINIUS

Abstract

The article analyses the methodological conditions under which low-frequency normal-direction vibration displacement can be used as an indicator of surface roughness in turning. The work is presented as an applied methodological analysis based on a previously published experimental case involving finish turning of EN AW-2011 aluminium alloy, synchronized displacement-roughness records, and contact profilometry measurements reported as R_a and R_z. The numerical analysis is based on 190 synchronized records. Within the analysed setup, the internal calibration yielded R² = 0.9929 and RMSE = 0.052 µm for R_a, and R² = 0.9905 and RMSE = 0.264 µm for R_z. The article emphasizes that low-rate displacement data should not be interpreted as chatter diagnostics or as a universal predictive model. Instead, such data can support setup-specific process-state monitoring when the sensing direction, sampling limitations, calibration procedure, error range and profilometric validation are explicitly defined. The analysis shows that a simple normal-direction displacement indicator can be useful in low-complexity monitoring environments, provided that it is periodically checked against direct roughness measurements and recalibrated after changes in material, tooling, machine setup or sensor mounting.