فهرست مقالات structural health monitoring

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  1 - The Effect of Corrosion Intensity on Damage Metric in Impedance-Based Structural Health Monitoring of an Aluminum Cantilever Beam
  A Askari F Hajami V Enjilela
  Metal corrosion is the main phenomenon in different industries and destructive effects of this chemical phenomenon cause a lot of costs annually. While corrosion causes a little mass decrease in structure, brings about a dramatic reduction in mechanical strength and fat چکیده کامل

  Metal corrosion is the main phenomenon in different industries and destructive effects of this chemical phenomenon cause a lot of costs annually. While corrosion causes a little mass decrease in structure, brings about a dramatic reduction in mechanical strength and fatigue life of corroded materials. Hence, health monitoring of a structure can make aware of structure status at any time and prevents from harmful consequences. Structural Health Monitoring based on Electromechanical Impedance is one of the real-time monitoring techniques that could recognize damage on a structure by using an electromechanical coupling of piezoelectric materials, immediately. On the other hand, due to high frequency used in this method, small defects in the early stages will be detected. In this paper, Structural Health Monitoring based on Electromechanical Impedance was applied in an aluminum cantilever beam to recognize the corrosion and evaluate the capability of the Electromechanical Impedance method in detecting corrosion. Furthermore, the standard deviation of the mean square root has been chosen as the main metric, that it increases as the defect size increases. Afterwards, Experimental results were compared with health monitoring theory based on the Electromechanical Impedance and more energy method. Subsequently, the experimental results represent this method efficiency in the immediate monitoring of damage caused by corrosion in an aluminum cantilever beam. Besides, the possibility of pinpointing the defect by using this way has shown a good relationship between the place of damage and damage metric پرونده مقاله
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  2 - Damage detection and structural health monitoring of ST-37 plate using smart materials and signal processing by artificial neural networks
  Hamid Reza Mirdamadi Farshad Ghasemi Javad Jafari
  Structural health monitoring (SHM) systems operate online and test different materials using ultrasonic guided waves and piezoelectric smart materials. These systems are permanently installed on the structures and display information on the monitor screen. The user info چکیده کامل

  Structural health monitoring (SHM) systems operate online and test different materials using ultrasonic guided waves and piezoelectric smart materials. These systems are permanently installed on the structures and display information on the monitor screen. The user informs the engineers of the existing damage after observing signal loss which appears after damage is caused. In this paper health monitoring is done for plate shaped structures made of ST-37 steel. After conducting the experimental tests, the stored signals by the multi-layer artificial neural network algorithm is processed and the damage caused in the plate is detected. By analyzing the graphs, it becomes clear that after causing damage the signal amplitude decreases. In the experimental test two piezoelectric discs are used on a steel plate which have been installed using a strong adhesive. Using a strong adhesive improves wave, propagation in the structure. Developing innovative testing methods for the SHM system has caused better control in structures after assembly. پرونده مقاله
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  3 - Placing sensors optimally in base-isolated steel structures using a multi-objective optimization approach
  Mehdi Firoozbakht Hamidreza Vosoughifar Alireza Ghari Ghoran
  10.30495/ijase.2023.1988832.1072
  Adequate selection of sensors placement plays a key role in structural health monitoring (SHM) in base isolated (BI) structures. This critical issue is usually done by past experience and knowledge on the force and vibration situations of a structure. During recent deca چکیده کامل

  Adequate selection of sensors placement plays a key role in structural health monitoring (SHM) in base isolated (BI) structures. This critical issue is usually done by past experience and knowledge on the force and vibration situations of a structure. During recent decades, techniques have received increasing attention as a tool for determining an arrangement of sensors suitable for SHM. In this paper, a multi- objective numerical method for optimal sensor placement (OSP) in BI structures based on the combination of traditional OSP algorithms and nonlinear time-history analysis (NTH) has been proposed. Next, genetic algorithm (GA) was employed to determine the location of sensors on the structure based on the structural dynamic response of the BI system. To show the efficiency of the proposed method, a BI building was modeled using finite element method (FEM) in which NTH were undertaken using the seismic scaled records of near-fault earthquakes (NF). The novel numerical approach called transformed time history to frequency domain (TTFD) was evaluated to transform NTH results to frequency domain and then the effective frequencies according the maximum range of Fourier amplitude were selected. The modified type of modal assurance criteria (MAC) values can be achieved from MAC with the exact seismic displacement. Results show that the proposed method can provide the optimal sensor locations and remarkably reduce the number of required sensors and also improve their optimum location. پرونده مقاله
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  4 - A Pitch-Catch Based Online Structural Health Monitoring of Pressure Vessels, Considering Corrosion Formation
  سیدحمیدرضا هاشمی حمیدرضا هوشیارمنش مجتبی قدسی
  Structural health monitoring is a developing research field which is multifunctional and can estimate the health condition of the structure by data analyzing and also can prognosticate the structural damages. Illuminating the damages by using piezoelectric sensors is on چکیده کامل

  Structural health monitoring is a developing research field which is multifunctional and can estimate the health condition of the structure by data analyzing and also can prognosticate the structural damages. Illuminating the damages by using piezoelectric sensors is one of the most effective techniques in structural health monitoring. Pressurized equipments are very important components in process industries such as oil, gas, petrochemical and power plants, that their health monitoring is vital. The aim of this research is to introduce a technique to illuminate the damages in these equipments by using guided waves. Thereby, two different specimens were used as pressurized vessels at different conditions: pristine and corroded. Different internal pressures were also studied. Piezoelectric transducers were electromechanically coupled to the vessels and the guided waves were propagated by using pitch-catch method. The outcomes indicated that damage parameters in vessels such as corrosion and pressure changes have considerable effect on the signals that piezoelectric sensors receive. Corrosion, the most common damage in pressurized vessels, reduce the signal domain in frequency field to 11%. Also increasing pressure reduce the signal domain.We can used these outcomes to innovate a technique for structural health monitoring of pressure equipmentss. پرونده مقاله