Mahnaz Shamshirsaz
Professor
Amirkabir University of Technology (Tehran Polytechnic)
Mahnaz Shamshirsaz received her MSc. and Ph.D. degrees in Mechanics from university of Lille I, France, respectively in 1991 and 1995. In 1995, she joined Department of Automation and Mechatronics, University of Aix-Marseille III, as a Research and Teaching Assistant working till 1998. She received a second MSc. degree in Robotics in 1998. She is currently Professor in Amirkabir University of Technology (Tehran Polytechnic) and Head of Mechtronics Laboratory in New Technologies Research Center. Her current research field is developing piezoelec
Participates in
TECHNICAL PROGRAMME | Energy Infrastructure
Pipelines, Storage and SPRs
Forum 08 | Digital Poster Plaza 2
28
April
12:30
14:30
UTC+3
Structural Health Monitoring (SHM) is recognized as an effective tool for enhancing safety and ensuring the integrity of structures, thereby reducing maintenance and repair costs. Among various techniques, the electro-mechanical impedance (EMI) method, which employs piezoelectric materials, has emerged in recent decades as a powerful, non-destructive, real-time approach for early damage detection in critical equipment and structures.
This research focuses on monitoring the health of buried pipelines subjected to transverse loading, using the electro-mechanical impedance method. This technique relies on the interaction between the structure (the pipe) and the piezoelectric material, which acts as both a sensor and an actuator. To address this problem, both finite element modeling and experimental testing have been employed. In particular, transverse loading on fuel transfer pipes is primarily caused by ground subsidence phenomena.
In the adopted method, any defect that affects the structure results in a change in its natural frequency, which in turn alters the structure’s frequency response. This leads to variations in the impedance of the structure. In this study, transverse loading and its effects—including stress, plastic deformation, and work hardening—are considered as potential damages to the pipe. The pipes tested are made of carbon steel X60, similar to those used in gas and oil transmission pipelines.
Initially, based on the actual model and existing standards, a small-scale laboratory model was designed in COMSOL Multiphysics software. For this model, considering laboratory capabilities, three-point bending and four-point bending experimental setups were modeled, and the impedance method was applied under both healthy and loaded conditions. Subsequently, experiments were conducted on specimens similar to these models. Piezoelectric patches were attached to the pipes, and by applying voltage to them, electro-mechanical impedance monitoring was performed during loading.
Finally, the results obtained from implementing the impedance method in COMSOL were compared with experimental data to validate the approach.
The results indicate that as stress increases, the impedance output shifts slightly to the right, and the resonance peaks of the impedance significantly increase. Moreover, due to plastic deformation and work hardening, the impedance signals exhibit behavior opposite to that in the elastic range; that is, before plasticity and within the elastic region, increasing load and tension lead to an increase in impedance amplitude with slight rightward shifts. However, after surpassing the elastic limit and entering the plastic zone, the impedance amplitude decreases and shifts leftward. Similar behavior is observed due to work hardening, with notable differences in amplitude variation compared to the elastic state. The behavior in this case is highly dependent on the magnitude of the applied load, especially in the plastic region.
Co-author/s:
Iman Jalilvand, Postdoctoral Research Fellow, University of British Columbia.
This research focuses on monitoring the health of buried pipelines subjected to transverse loading, using the electro-mechanical impedance method. This technique relies on the interaction between the structure (the pipe) and the piezoelectric material, which acts as both a sensor and an actuator. To address this problem, both finite element modeling and experimental testing have been employed. In particular, transverse loading on fuel transfer pipes is primarily caused by ground subsidence phenomena.
In the adopted method, any defect that affects the structure results in a change in its natural frequency, which in turn alters the structure’s frequency response. This leads to variations in the impedance of the structure. In this study, transverse loading and its effects—including stress, plastic deformation, and work hardening—are considered as potential damages to the pipe. The pipes tested are made of carbon steel X60, similar to those used in gas and oil transmission pipelines.
Initially, based on the actual model and existing standards, a small-scale laboratory model was designed in COMSOL Multiphysics software. For this model, considering laboratory capabilities, three-point bending and four-point bending experimental setups were modeled, and the impedance method was applied under both healthy and loaded conditions. Subsequently, experiments were conducted on specimens similar to these models. Piezoelectric patches were attached to the pipes, and by applying voltage to them, electro-mechanical impedance monitoring was performed during loading.
Finally, the results obtained from implementing the impedance method in COMSOL were compared with experimental data to validate the approach.
The results indicate that as stress increases, the impedance output shifts slightly to the right, and the resonance peaks of the impedance significantly increase. Moreover, due to plastic deformation and work hardening, the impedance signals exhibit behavior opposite to that in the elastic range; that is, before plasticity and within the elastic region, increasing load and tension lead to an increase in impedance amplitude with slight rightward shifts. However, after surpassing the elastic limit and entering the plastic zone, the impedance amplitude decreases and shifts leftward. Similar behavior is observed due to work hardening, with notable differences in amplitude variation compared to the elastic state. The behavior in this case is highly dependent on the magnitude of the applied load, especially in the plastic region.
Co-author/s:
Iman Jalilvand, Postdoctoral Research Fellow, University of British Columbia.
