Crack Assessment Based on the Use
of Severity-Adjusted Modal Curvatures
of the Healthy Beam
Gilbert-Rainer Gillich , Cristian Tufisi , Magd Abdel Wahab ,
and Codruta Oana Hamat
Abstract The current paper presents an algorithm for locating transverse cracks
present in Euler–Bernoulli steel beams, by considering the relative frequency shifts
(RFSs) measured for the weak-axis vibration modes and the mode shape curvatures.
To apply the algorithm, we first determine, by means of the finite element method
(FEM), the natural frequencies for the first four bending vibration modes for the
healthy beam fixed-free and fixed-fixed end conditions. Afterward, we introduced
transverse cracks with known depth and location and determined again the natural
frequencies. As a next step, we use an original algorithm to plot the potential severity
curves (PSCs) for the four modes and find the intersection, which indicates the crack
severity and location. It was found that the method is reliable for determining the location of transverse cracks just by using the measured natural frequency and the squared
normalized modal curvatures (SNMCs) for both imposed boundary conditions.
1 Introduction
As our society further develops, the need for more advanced methods for evaluating
structural integrity of buildings, structures and mechanical aggregates is more of a
priority. It is no surprise that structures failed over time due to faulty production
technologies, natural aging phenomena and the lack of structural integrity analysis
methods carried out over functioning time. Vibrational-based methods can evaluate a
structure after its production and help determining its ability of maintaining functionality in real time, before structural failing happens [1]. Damage detection methods
G.-R. Gillich (B) · C. Tufisi · C. O. Hamat
“Eftimie Murgu” University of Resita, P-ta TraianVuia 1-4, 320085 Resita, Romania
e-mail: gr.gillich@uem.ro
M. Abdel Wahab
Ghent University, 9052 Zwijnaarde, Belgium
© Springer Nature Switzerland AG 2021
N. Herisanu and V. Marinca (eds.), Acoustics and Vibration of Mechanical
Structures—AVMS 2019, Springer Proceedings in Physics 251,
https://doi.org/10.1007/978-3-030-54136-1_50
499
of Severity-Adjusted Modal Curvatures
of the Healthy Beam
Gilbert-Rainer Gillich , Cristian Tufisi , Magd Abdel Wahab ,
and Codruta Oana Hamat
Abstract The current paper presents an algorithm for locating transverse cracks
present in Euler–Bernoulli steel beams, by considering the relative frequency shifts
(RFSs) measured for the weak-axis vibration modes and the mode shape curvatures.
To apply the algorithm, we first determine, by means of the finite element method
(FEM), the natural frequencies for the first four bending vibration modes for the
healthy beam fixed-free and fixed-fixed end conditions. Afterward, we introduced
transverse cracks with known depth and location and determined again the natural
frequencies. As a next step, we use an original algorithm to plot the potential severity
curves (PSCs) for the four modes and find the intersection, which indicates the crack
severity and location. It was found that the method is reliable for determining the location of transverse cracks just by using the measured natural frequency and the squared
normalized modal curvatures (SNMCs) for both imposed boundary conditions.
1 Introduction
As our society further develops, the need for more advanced methods for evaluating
structural integrity of buildings, structures and mechanical aggregates is more of a
priority. It is no surprise that structures failed over time due to faulty production
technologies, natural aging phenomena and the lack of structural integrity analysis
methods carried out over functioning time. Vibrational-based methods can evaluate a
structure after its production and help determining its ability of maintaining functionality in real time, before structural failing happens [1]. Damage detection methods
G.-R. Gillich (B) · C. Tufisi · C. O. Hamat
“Eftimie Murgu” University of Resita, P-ta TraianVuia 1-4, 320085 Resita, Romania
e-mail: gr.gillich@uem.ro
M. Abdel Wahab
Ghent University, 9052 Zwijnaarde, Belgium
© Springer Nature Switzerland AG 2021
N. Herisanu and V. Marinca (eds.), Acoustics and Vibration of Mechanical
Structures—AVMS 2019, Springer Proceedings in Physics 251,
https://doi.org/10.1007/978-3-030-54136-1_50
499