On the feasibility of utilizing vibrations for bolted joint assessment

For many technical installations held together by bolted joints, the regular checking and documentation of proper bolt tightness is essential for certification and safe operation. With large structures and heavy bolts, this requires long hours of monotonous and physically demanding physical work, possibly in tough environments. A better way of monitoring bolt tightness is on high demand in many industries.
The presented study is based on recent experimental results and theoretical studies that indicate and explain the correlation between transient bolt vibrations due to e.g. a hammer impact and bolt tension. The study presents an overview of the features that can be extracted from measured vibrational response and can characterize bolt tension. The main objective of the study is to discuss the practical applicability of these features to robust detection of loosen bolts and a feasibility of a relatively simple and not demanding vibration-based system to monitor bolt tension in industrial environments.