Identification of damage based on frequency response function (FRF) data

Abstract

Abstract. Mechanical joints, particularly fasteners such as bolted joints have a complex non-linear behaviour. The non-linearity might emerge from the material, geometry or by the contacts in the joints. However, damage to a structure can be happened either their connections or the material of components. The effect of damage can change the dynamic properties of the structure such as natural frequencies and mode shapes and structural performance and can cause premature failure to structure. This paper presents a damage detection method using a vibration based damage detection method based on the frequency response function (FRF) data. A combination of numerical model and physical bolted jointed structure of damaged and undamaged structure will be investigated. The validation is employed to detect the presence of damage in the structure based on the frequency response function (FRF) data from the parameter values used in the benchmark model and damaged model. The comparisons of the undamaged and damaged structure of the FRF have revealed the damaged structure was shifted from the undamaged structure. The effect of the FRF between undamaged and damaged structure is clearly affected by the reduction of stiffness for the damaged structure.

Wykrywanie Uszkodzeń Węzłów W Modelu Ramy Stalowej Na Podstawie Analizy Inertancji

“…Funkcja przejścia opisuje relację pomiędzy wymuszeniem a rejestrowaną odpowiedzią konstrukcji [2]. Możliwość wykorzystania funkcji przejścia do detekcji uszkodzeń została zaprezentowana między innymi w [3], [4], [5] i [6]. W [3] funkcję przejścia potraktowano jako sygnał.…”

“…Przeprowadzony eksperyment bazował niestety wyłącznie na danych numerycznych. Nieco inne podejście zaproponowano w pracy [4], gdzie wykazano, że wystąpienie uszkodzenia w układzie powoduje przesunięcie wykresu funkcji w stronę niższych częstotliwości, a ocena, czy uszkodzenie wystąpiło czy nie możliwa jest poprzez wizualne porównanie funkcji dla układu wzorcowego i uszkodzonego. W pracy [5] pokazano skuteczność detekcji uszkodzeń na rzeczywistym obiekcie (most), a w [6] wykorzystano FRF do identyfikacji uszkodzenia w postaci zmiany sztywności połączeń.…”

Adaptive Probabilistic Optimization Approach for Vibration-Based Structural Health Monitoring

“…The use of the frequency response function (FRF) for damage detection and structural health monitoring has been widespread [8][9][10]. Recently, the use of FRF has been augmented by using artificial neural networks (ANN) and genetic algorithms (GA) for damage detection [11][12][13]. It has been specifically observed that ANN could be used for the detection of nonlinear damage with a high level of accuracy [11]; however, most of the techniques that use ANN require a large amount of training data.…”

Detection of Anomaly in a Pretensioned Bolted Beam-to-Column Connection Node Using Digital Image Correlation and Neural Networks

“…However, this approach is not ready to be applied in field tests since high measurement accuracy is required but is difficult to be obtained in real-life structure measurements. The article [9] shows the impact of loosening connectors in the Frequency Response Function (FRF), which changes not only its shape but also decreases the resonance frequencies values. The publication also highlights the complex non-linear nature of bolted connections.…”