TY - GEN
T1 - Identification of Local Debonding in Bolted Panels Using Nonlinear Pseudo-forces
AU - Xu, Wei
AU - Ji, Mincong
AU - Cao, Maosen
AU - Su, Zhongqing
AU - Ostachowicz, Wiesław
N1 - Publisher Copyright:
© 2024 SPIE.
PY - 2024/3
Y1 - 2024/3
N2 - Bolt looseness can occur subject to long-term structural service. With this concern of structural integrity and safety, there is a huge demand to identify bolt-looseness-caused local debonding in connected structural components such as bolted panels. With the aid of non-contact laser scanning, transverse operating deflection shapes (ODSs) of a bolted panel can be measured with high spatial resolutions. Perturbation to the linear transverse dynamic equilibrium of the panel can be regarded as the linear pseudo-force (LPF), which is applied to the debonding region only and vanishes at undamaged locations. However, nonlinearities caused by contact of debonding interfaces during vibrations are not taken into consideration in the LPF model. As a consequence, only linear damage features can be contained in the LPFs which are established on linear ODSs, leading to incompleteness of damage features. Addressing this problem, this study establishes a nonlinear pseudo-force (NPF) model from the nonlinear transverse motion of equation of a beam-type bi-layer panel model with local debonding. Superior to LPFs, NPFs can extract linear and nonlinear damage features from linear and nonlinear ODSs, respectively. Similar to LPFs, NPFs concentrate in the debonding regions to form local peaks. Therefore, the NPF can be utilized as an ideal nonlinear indicator for the identification of local debonding in bolted panels. The applicability of the NPF is experimentally validated by identifying width-through debonding in a steel panel connected by bolts, whose ODSs at linear and nonlinear (higher) harmonics are acquired through non-contact laser scanning measurement. Experimental results reveal that the NPF can extract complete linear and nonlinear damage features, and hence has a higher-dimensional capacity for identifying local debonding in connected structural components such as bolted panels, whose occurrence, location, and size can be graphically characterized.
AB - Bolt looseness can occur subject to long-term structural service. With this concern of structural integrity and safety, there is a huge demand to identify bolt-looseness-caused local debonding in connected structural components such as bolted panels. With the aid of non-contact laser scanning, transverse operating deflection shapes (ODSs) of a bolted panel can be measured with high spatial resolutions. Perturbation to the linear transverse dynamic equilibrium of the panel can be regarded as the linear pseudo-force (LPF), which is applied to the debonding region only and vanishes at undamaged locations. However, nonlinearities caused by contact of debonding interfaces during vibrations are not taken into consideration in the LPF model. As a consequence, only linear damage features can be contained in the LPFs which are established on linear ODSs, leading to incompleteness of damage features. Addressing this problem, this study establishes a nonlinear pseudo-force (NPF) model from the nonlinear transverse motion of equation of a beam-type bi-layer panel model with local debonding. Superior to LPFs, NPFs can extract linear and nonlinear damage features from linear and nonlinear ODSs, respectively. Similar to LPFs, NPFs concentrate in the debonding regions to form local peaks. Therefore, the NPF can be utilized as an ideal nonlinear indicator for the identification of local debonding in bolted panels. The applicability of the NPF is experimentally validated by identifying width-through debonding in a steel panel connected by bolts, whose ODSs at linear and nonlinear (higher) harmonics are acquired through non-contact laser scanning measurement. Experimental results reveal that the NPF can extract complete linear and nonlinear damage features, and hence has a higher-dimensional capacity for identifying local debonding in connected structural components such as bolted panels, whose occurrence, location, and size can be graphically characterized.
KW - bolted panel
KW - laser scanning measurement
KW - local debonding identification
KW - nonlinear harmonics
KW - nonlinear ODS
KW - nonlinear pseudo-force
UR - http://www.scopus.com/inward/record.url?scp=85194877713&partnerID=8YFLogxK
U2 - 10.1117/12.3009653
DO - 10.1117/12.3009653
M3 - Conference article published in proceeding or book
AN - SCOPUS:85194877713
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Health Monitoring of Structural and Biological Systems XVIII
A2 - Su, Zhongqing
A2 - Peters, Kara J.
A2 - Ricci, Fabrizio
A2 - Rizzo, Piervincenzo
PB - SPIE
T2 - Health Monitoring of Structural and Biological Systems XVIII 2024
Y2 - 25 March 2024 through 28 March 2024
ER -