List of Articles Hesam Makvandi

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  1 - Crack detection in pressurized pipes using Harris hawk optimization method
  Afshin Fathi Hesam Makvandi
  Sudden failure in structures is one of the results of the presence of defects in parts, which have led to many economic and human damages. Since the creation and growth of cracks can lead to component failure, many researchers have investigated methods to detect the pre More

  Sudden failure in structures is one of the results of the presence of defects in parts, which have led to many economic and human damages. Since the creation and growth of cracks can lead to component failure, many researchers have investigated methods to detect the presence of cracks in the structure. Due to the widespread use of pipes in various industries, inspection of pipes is one of the most important issues in the industry. The purpose of this research is to provide a method for crack detection (investigating crack depth and location) in pressurized pipes using modal analysis and differential quadrature method. For this purpose, first calculating the natural frequencies of the vibrations of the defective pipe, the effect of the characteristics of the crack on the vibrations of the structure is investigated, then using the Harris hawk optimization method, the location and depth of the crack is calculated using the frequencies of the cracked pipe vibrations. Examining the results obtained for cracked pipes under fluid pressure confirms the correctness and accuracy of the presented method for direct and inverse solution. Manuscript profile
• Open Access Article
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  2 - Investigating the performance of several frequency domain and time domain methods in calculating the dynamic parameters of a three-story structure using operational modal analysis
  Mohsen Mahdavi Adeli Hesam Makvandi
  In this research, a practical method for finding modal parameters in structures is investigated. At first, two methods in the frequency domain called FDD and EFDD frequency domain analysis methods and a time domain method called SSI are defined. In order to check the ac More

  In this research, a practical method for finding modal parameters in structures is investigated. At first, two methods in the frequency domain called FDD and EFDD frequency domain analysis methods and a time domain method called SSI are defined. In order to check the accuracy of these methods in identifying the modal parameters of real structures, a three-story structure modeled in Ansys software will be used. This structure was modeled by Ansys software and the correctness of the model performance was confirmed by comparing the results of modal analysis of the structure with the results of experimental tests. The acceleration response obtained from the created model is given as an input to environmental modal analysis methods, whose responses are compared with actual results. It was observed that all three methods could estimate the frequencies, mode shapes and damping coefficients of the structure with high accuracy. It is also observed that using the SSI method is easier, but the FDD and EFDD methods need less time to solve. Manuscript profile