Engineering Commons^™

Towards Intelligent Structural Health Monitoring Of Infrastructure Systems: An Interdisciplinary Study Of Acoustic Emission Monitoring, Numerical Simulation, And Artificial Intelligence, Li Ai

Theses and Dissertations

Some complex infrastructure systems, such as nuclear facilities and bridges, are subject to structural damage due to environmental erosion, material deterioration, and other factors after long periods of use. Stress corrosion cracking (SCC) and alkali-silica reaction (ASR) have been identified as the primary degradation mechanisms for steel and concrete structures in nuclear facilities and bridges. Ensuring the integrity and operational safety of structures during their lifetime is an important task. Nondestructive methods and structural health monitoring can be used to detect damage caused by SCC and ASR instead of conventional visual inspection. Among the nondestructive methods, acoustic emission (AE) is …

An Acoustic Emission And Artificial Intelligence Approach To Structural Health Monitoring For Aerospace Application, Joseph Chandler Garrett

Theses and Dissertations

In the area of aerospace and other applications, structural health monitoring (SHM) has been a significant and growing area of research in recent years. Throughout the operational life of aerospace structures, various damage scenarios may manifest, and it is of great concern to the aerospace community to develop methodologies for detecting and assessing these damage scenarios. In this paper, fundamental research on the use of the acoustic emission (AE) approach to SHM for fatigue crack growth is presented. In general, the AE approach to SHM and non-destructive evaluation (NDE) involves the sensing of ultrasonic Lamb waves propagating through a structure. …

Impact Damage Ascertainment In Composite Plates Using In-Situ Acoustic Emission Signal Signature Identification, Robin James, Roshan Prakash Joseph, Victor Giurgiutiu

Faculty Publications

Barely visible impact damage (BVID) due to low velocity impact events in composite aircraft structures are becoming prevalent. BVID can have an adverse effect on the strength and safety of the structure. During aircraft inspections it can be extremely difficult to visually detect BVID. Moreover, it is also a challenge to ascertain if the BVID has in-fact caused internal damage to the structure or not. This paper describes a method to ascertain whether or not internal damage happened during the impact event by analyzing the high-frequency information contained in the recorded acoustic emission signal signature. Multiple 2 mm quasi-isotropic carbon …

Evaluation Of Temporal Damage Progression In Concrete Structures Affected By Asr Using Data-Driven Methods, Vafa Soltangharaei

Theses and Dissertations

Alkali-silica reaction (ASR) is a chemical reaction, which causes damage in concrete structures such as bridges, dams, and nuclear containments and powerplant structures. The ASR-induced damage may endanger the integrity and serviceability of structures. Several methods such as visual inspection, petrographic analysis, demountable mechanical strain gauges, and cracking index have been utilized for study the effect of ASR on structures, which are not always efficient in early damage detection and some are destructive and prohibited in nuclear structures. Nondestructive methods and structural health monitoring techniques can be alternatives for the condition assessment of structures. Among the nondestructive methods, acoustic emission …

Investigating The Effects Of Aggregate Size And Reinforcement On Asr Cracking In Concrete Structures Studied With Different Evaluation Methods, David Joseph Bianco

Theses and Dissertations

The objective of this thesis is to investigate different (non-destructive) evaluation methods to assess the effects of reactive aggregate size and reinforcement on ASR affected concrete. It has been shown in previous literature that reactive coarse aggregates lead to more expansion as opposed to reactive fine aggregates. However, there is a lack in the literature exhibiting this relationship using different evaluation methods, such as acoustic emission (AE) and ultrasonic pulse velocity (UPV). Also, the literature does not emphasize the role this relationship plays when the concrete is imposed with stress boundary conditions. Non-destructive test methods, including acoustic emission, are becoming …

Acoustic Emission And Guided Wave Modeling And Experiments For Structural Health Monitoring And Non-Destructive Evaluation, Roshan Prakash Joseph

Theses and Dissertations

This dissertation is organized into major parts. In Part I of the dissertation, plate guided waves due to an acoustic emission (AE) event are analytically studied in the context of seismic moment tensor sources. The guided wave propagation elastodynamic equation corresponding to a point source applied to the plate in an arbitrary direction is modified in order to describe the case when the source is a seismic moment tensor of various tensor components. This part of the dissertation also discusses the analytical modeling of AE test sources such as pencil lead break, hammer hit excitation, etc.

In Part II of …

Recent Advances In Piezoelectric Wafer Active Sensors For Structural Health Monitoring Applications, Hanfei Mei, Mohammad Faisal Haider, Roshan Prakash Joseph, Asaad Migot, Victor Giurgiutiu

Faculty Publications

In this paper, some recent piezoelectric wafer active sensors (PWAS) progress achieved in our laboratory for active materials and smart structures (LAMSS) at the University of South Carolina: http: //www.me.sc.edu/research/lamss/ group is presented. First, the characterization of the PWAS materials shows that no significant change in the microstructure after exposure to high temperature and nuclear radiation, and the PWAS transducer can be used in harsh environments for structural health monitoring (SHM) applications. Next, PWAS active sensing of various damage types in aluminum and composite structures are explored. PWAS transducers can successfully detect the simulated crack and corrosion damage in aluminum …

Recent Advances In Piezoelectric Wafer Active Sensors For Structural Health Monitoring Applications, Hanfei Mei, Mohammad Faisal Haider, Roshan Joseph, Asaad Migot, Victor Giurgiutiu

Faculty Publications

In this paper, some recent piezoelectric wafer active sensors (PWAS) progress achieved in our laboratory for active materials and smart structures (LAMSS) at the University of South Carolina: http: //www.me.sc.edu/research/lamss/ group is presented. First, the characterization of the PWAS materials shows that no significant change in the microstructure after exposure to high temperature and nuclear radiation, and the PWAS transducer can be used in harsh environments for structural health monitoring (SHM) applications. Next, PWAS active sensing of various damage types in aluminum and composite structures are explored. PWAS transducers can successfully detect the simulated crack and corrosion damage in aluminum …

Damage Mechanism Evaluation Of Large-Scale Concrete Structures Affected By Alkali-Silica Reaction Using Pattern Recognition, Vafa Soltangharaei, Rafal Anay, Nolan Wesley Hayes, Lateef Assi, Yann Le Pape, Zhongguo John Ma, Paul Ziehl

Faculty Publications

Alkali-silica reaction has caused damage to concrete structures, endangering structural serviceability and integrity. This is of concern in sensitive structures such as nuclear power plants. In this study, acoustic emission (AE) was employed as a structural health monitoring strategy in large-scale, reinforced concrete specimens affected by alkali-silica reaction with differing boundary conditions resembling the common conditions found in nuclear containments. An agglomerative hierarchical algorithm was utilized to classify the AE data based on energy-frequency based features. The AE signals were transferred into the frequency domain and the energies in several frequency bands were calculated and normalized to the total energy …