Tapping and listening: a new approach to bolt looseness monitoring

Abstract

Bolted joints are among the most common building blocks used across different types of structures, and are often the key components that sew all other structural parts together. Monitoring and assessment of looseness in bolted structures is one of the most attractive topics in mechanical, aerospace, and civil engineering. This paper presents a new percussion-based non-destructive approach to determine the health condition of bolted joints with the help of machine learning. The proposed method is very similar to the percussive diagnostic techniques used in clinical examinations to diagnose the health of patients. Due to the different interfacial properties among the bolts, nuts and the host structure, bolted joints can generate unique sounds when it is excited by impacts, such as from tapping. Power spectrum density, as a signal feature, was used to recognize and classify recorded tapping data. A machine learning model using the decision tree method was employed to identify the bolt looseness level. Experiments demonstrated that the newly proposed method for bolt looseness detection is very easy to implement by ‘listening to tapping’ and the monitoring accuracy is very high. With the rapid in robotics, the proposed approach has great potential to be implemented with intimately weaving robotics and machine learning to produce a cyber-physical system that can automatically inspect and determine the health of a structure.

Detecting Debonding between Steel Beam and Reinforcing CFRP Plate Using Active Sensing with Removable PZT-Based Transducers

“…Future work will involve the integration of the proposed removable PZT transducers with robotic manipulators to automate the debonding detection of CFRP reinforced steel beams. In addition, the percussion or the tapping-and-listening-based approaches have been recently reported for damage detection [61][62][63], which motivates us to investigate detection of the debonding of the CRRP reinforcement by using the percussion approach in future work. To model the debonding process between a steel beam and the reinforcing CFRP plate, we plan to use the fractal contact theory [64,65] to analyze the stress wave attenuation across the debonding zone.…”

Predicting the Loose Zone of Roadway Surrounding Rock Using Wavelet Relevance Vector Machine

“…For many years, rock bolts are commonly used to enhance the stability of surrounding rock [2][3][4][5]. However, rock bolts are subjected to the loose zone of pre-load [6][7][8] or corrosion [9][10][11] and may fail [12]. The thickness determination of loose zone is not only a significant factor for the roadway surrounding rock's stability, but also an important basis for the design of roadway support.…”

Preload Monitoring in Bolted Connection Using Piezoelectric-Based Smart Interface

“…After a long-term service life, however, bolted connections could experience loss of preloads (i.e., self-loosening) due to repetitive external forces and vibrations, those threaten their functionality. Therefore, bolt preload monitoring is essential and recently gained growing interest in efforts to ensure the safety of bolted joints and to prevent the catastrophic failures of entire structures [1][2][3][4][5][6].…”