Open Access

Article

Article ID: 2372

Innovative intelligent and expert system of bridges damage identification via wavelet packet energy curvature difference method integrated with artificial intelligence algorithms

by Wael A. Altabey

Sound & Vibration, Vol.59, No.2, 2025;

Bridges are important infrastructure for highways. Monitoring their status is of great significance to ensure safe operations. In this work, a novel integrated technique from wavelet packet energy curvature difference (WPECD) and artificial intelligence (AI) for bridge damage identification is established. Initially, the damages are simulated in the bridge decks by changing the material stiffness reduction levels of bridge elements by three levels (5%, 10%, 15%) to study the effect of damage on the bridge response. Then the WPECD maps are plotted from vibration response before and after damage to the bridge for each stiffness reduction level. Unfortunately, given the nonlinearity of damage geometry, it is not easily feasible to use WPECD maps for damage identification accurately. Therefore, the (WPECD) maps are used for training a new architecture of recurrent neural networks with long short-term memory blocks (RNN-LSTM) for bridge damage identification by predicting the wavelet functions and wavelet decomposition layer effect of each node in the bridge. The effectiveness and reliability of the proposed approach were confirmed by numerical and experimental results. The performance of the proposed technique achieved high scores of accuracy, regression, and F-score equal to 93.58%, 90.43% and 88.17% respectively indicating the applicability of the proposed method for use on other important highway infrastructure.

Open Access

Article

Article ID: 2358

Scrutinizing highly nonlinear oscillators using He’s frequency formula

by Gamal M. Ismail, Galal M. Moatimid, Ibrahim Alraddadi, Stylianos V. Kontomaris

Sound & Vibration, Vol.59, No.2, 2025;

Highly nonlinear oscillators are examined in their capacity to simulate intricate systems in engineering, physics, biology, and finance, as well as their diverse behavior, rendering them essential in the development of resilient systems and technological advancement. Therefore, the fundamental purpose of the current work is to analyze He’s frequency formula (HFF) to get theoretical explanations of many types of very nonlinear oscillators. We investigate, in both analytical and computational, the relationship between elastic forces and the solution of a specific oscillator. This oscillator exhibits significant nonlinear damping. It is assumed that the required quantity of trigonometric functions matches the solution of a strong nonlinear ordinary differential equation (ODE) that explains the motion. The novel approach definitely takes less processing time and is less complex than the traditional perturbation methods that were widely used in this field. This novel method, which is essentially giving a linearization of the nonlinear ODE, is known as the non-perturbative approach (NPA). This procedure produces a new frequency that is similar to a linear ODE, much as in a fundamental harmonic scenario. Readers will benefit from an in-depth account of the NPA. The theoretical findings are validated by numerical examination using Mathematical Software (MS). The theoretical and numerical solution (NS) tests yielded fairly similar findings. It is a well-established principle that classical perturbation methods trust on Taylor expansions to approximate restoring forces, therefore simplifying the current situation. When the NPA is used, this vulnerability does not present. Furthermore, the NPA enables a thorough assessment of the problems’ stability analysis, which was a not possible using prior conventional methodology. Consequently, the NPA is a more appropriate responsibility tool for examining approximations in extremely nonlinear oscillators in MS.

Open Access

Editorial

Article ID: 2627

Vibration: A bibliometric analysis

by João Paulo Davim

Sound & Vibration, Vol.59, No.2, 2025;

Vibration is a mechanical phenomenon in which oscillations occur around an equilibrium point. The Scopus database was used for the bibliometric analysis, based on the term {vibration}. The better result shows in the function of the number of documents produced: year 2024; source Proceedings of SPIE; author Inman, D.J.; affiliation Ministry of Education of China; country China; document type article; scientific area Engineering and funding support National Natural Science Foundation of China.