Next Article in Journal
Design of Event-Triggered Fault-Tolerant Control for Stochastic Systems with Time-Delays
Next Article in Special Issue
A Temperature Drift Compensation Method for Pulsed Eddy Current Technology
Previous Article in Journal
Thermal Energy Harvesting on the Bodily Surfaces of Arms and Legs through a Wearable Thermo-Electric Generator
Previous Article in Special Issue
Development of A Low-Cost FPGA-Based Measurement System for Real-Time Processing of Acoustic Emission Data: Proof of Concept Using Control of Pulsed Laser Ablation in Liquids
Article

Preload Monitoring of Bolted L-Shaped Lap Joints Using Virtual Time Reversal Method

by 1, 1,*, 1,2 and 3
1
School of Astronautics, Northwestern Polytechnical University, Xi’an 710072, China
2
Mechanical Engineering Department, University of Maryland Baltimore County, Baltimore, MD 21250, USA
3
Department of Mechanical Engineering, University of Bristol, Bristol BS81TR, UK
*
Author to whom correspondence should be addressed.
Sensors 2018, 18(6), 1928; https://doi.org/10.3390/s18061928
Received: 1 May 2018 / Revised: 5 June 2018 / Accepted: 12 June 2018 / Published: 13 June 2018
L-shaped bolt lap joints are commonly used in aerospace and civil structures. However, bolt joints are frequently subjected to loosening, and this has a significant effect on the safety and reliability of these structures. Therefore, bolt preload monitoring is very important, especially at the early stage of loosening. In this paper, a virtual time reversal guided wave method is presented to monitor preload of bolted L-shaped lap joints accurately and simply. In this method, a referenced reemitting signal (RRS) is extracted from the bolted structure in fully tightened condition. Then the RRS is utilized as the excitation signal for the bolted structure in loosening states, and the normalized peak amplitude of refocused wave packet is used as the tightness index (TIA). The proposed method is experimentally validated by L-shaped bolt joints with single and multiple bolts. Moreover, the selections of guided wave frequency and tightness index are also discussed. The results demonstrate that the relationship between TIA and bolt preload is linear. The detection sensitivity is improved significantly compared with time reversal (TR) method, particularly when bolt loosening is at its embryo stage. The results also show that TR method is an effective method for detection of the number of loosening bolts. View Full-Text
Keywords: bolt preload monitoring; bolt joints; time reversal; structural health monitoring; guided wave bolt preload monitoring; bolt joints; time reversal; structural health monitoring; guided wave
Show Figures

Figure 1

MDPI and ACS Style

Du, F.; Xu, C.; Wu, G.; Zhang, J. Preload Monitoring of Bolted L-Shaped Lap Joints Using Virtual Time Reversal Method. Sensors 2018, 18, 1928. https://doi.org/10.3390/s18061928

AMA Style

Du F, Xu C, Wu G, Zhang J. Preload Monitoring of Bolted L-Shaped Lap Joints Using Virtual Time Reversal Method. Sensors. 2018; 18(6):1928. https://doi.org/10.3390/s18061928

Chicago/Turabian Style

Du, Fei, Chao Xu, Guannan Wu, and Jie Zhang. 2018. "Preload Monitoring of Bolted L-Shaped Lap Joints Using Virtual Time Reversal Method" Sensors 18, no. 6: 1928. https://doi.org/10.3390/s18061928

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop