TY - GEN
T1 - Damage Identification in Beams by Post-processing Modal Displacements and Rotations with Haar Wavelet
AU - dos Santos, J. V.Araújo
AU - Lopes, H.
AU - Katunin, A.
N1 - Publisher Copyright:
© 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.
PY - 2021
Y1 - 2021
N2 - A study on the post-processing of modal displacements and modal rotations with the Haar wavelet is presented in this paper. A free-free aluminum beam is chosen as a structure to be analyzed and its modal displacements and rotations in both undamaged and multiple damaged states are computed with the finite element method. Three sets of damage indicators are proposed: (1) wavelet transform of damaged modal displacements or modal rotations, (2) wavelet transform of differences in modal displacements or modal rotations, and (3) ratio of wavelet transform of differences in modal displacements or modal rotations to wavelet transform of undamaged modal displacements or modal rotations. The study shows that post-processing modal displacements with the Haar wavelet leads to poor damage identifications. On the other hand, if one applies the same type of wavelet to modal rotations, the damage indicators (2) and (3) clearly pinpoints the location of the damage. Although the set of damage indicators (1) and (2) are prone to the boundary effect, where high values of wavelets coefficients are present, the third set of damage indicators does not present this problem. Furthermore, for large values of damage, this damage indicators shows the presence of damage in all scales of the wavelet scalogram. The present study clearly shows that by post-processing modal rotations with the simplest wavelet one can obtain reliable identifications of multiple damage.
AB - A study on the post-processing of modal displacements and modal rotations with the Haar wavelet is presented in this paper. A free-free aluminum beam is chosen as a structure to be analyzed and its modal displacements and rotations in both undamaged and multiple damaged states are computed with the finite element method. Three sets of damage indicators are proposed: (1) wavelet transform of damaged modal displacements or modal rotations, (2) wavelet transform of differences in modal displacements or modal rotations, and (3) ratio of wavelet transform of differences in modal displacements or modal rotations to wavelet transform of undamaged modal displacements or modal rotations. The study shows that post-processing modal displacements with the Haar wavelet leads to poor damage identifications. On the other hand, if one applies the same type of wavelet to modal rotations, the damage indicators (2) and (3) clearly pinpoints the location of the damage. Although the set of damage indicators (1) and (2) are prone to the boundary effect, where high values of wavelets coefficients are present, the third set of damage indicators does not present this problem. Furthermore, for large values of damage, this damage indicators shows the presence of damage in all scales of the wavelet scalogram. The present study clearly shows that by post-processing modal rotations with the simplest wavelet one can obtain reliable identifications of multiple damage.
KW - Beam
KW - Boundary effect
KW - Finite element method
KW - Modal displacement and modal rotation
KW - Multiple damage identification
KW - Wavelet transform
UR - https://www.scopus.com/pages/publications/85102274502
U2 - 10.1007/978-3-030-64908-1_76
DO - 10.1007/978-3-030-64908-1_76
M3 - Conference contribution
AN - SCOPUS:85102274502
SN - 9783030649074
T3 - Lecture Notes in Civil Engineering
SP - 817
EP - 824
BT - European Workshop on Structural Health Monitoring - Special Collection of 2020 Papers - Volume 2
A2 - Rizzo, Piervincenzo
A2 - Milazzo, Alberto
PB - Springer Science and Business Media Deutschland GmbH
T2 - 10th European Workshop on Structural Health Monitoring, EWSHM 2020
Y2 - 1 July 2022 through 1 July 2022
ER -