Ameneh Maghsoodi - Academia.edu (original) (raw)

Papers by Ameneh Maghsoodi

Research paper thumbnail of Calculation of Wave Dispersion Curves in Multilayered Composite-Metal Plates

Shock and Vibration, 2014

The major purpose of this paper is the development of wave dispersion curves calculation in multi... more The major purpose of this paper is the development of wave dispersion curves calculation in multilayered composite-metal plates. At first, equations of motion and characteristic equations for the free waves on a single-layered orthotropic plate are presented. Since direction of wave propagation in composite materials is effective on equations of motion and dispersion curves, two different cases are considered: propagation of wave along an axis of material symmetry and along off-axes of material symmetry. Then, presented equations are extended for a multilayered orthotropic composite-metal plate using the transfer matrix method in which a global transfer matrix may be extracted which relates stresses and displacements on the top layer to those on the bottom one. By satisfying appropriate boundary conditions on the outer boundaries, wave characteristic equations and then dispersion curves are obtained. Moreover, presented equations may be applied to other materials such as monoclinic, transversely isotropic, cubic, and isotropic materials. To verify the solution procedure, a number of numerical illustrations for a single-layered orthotropic and double-layered orthotropic-metal are presented.

Research paper thumbnail of Multiple-crack damage detection in multi-step beams by a novel local flexibility-based damage index

Journal of Sound and Vibration, 2013

Research paper thumbnail of Vibration based algorithm for crack detection in cantilever beam containing two different types of cracks

Vibration based algorithm for crack detection in cantilever beam containing two different types of cracks

Journal of Sound and Vibration, 2013

ABSTRACT In this paper, a simple method for detection of multiple edge cracks in Euler-Bernoulli ... more ABSTRACT In this paper, a simple method for detection of multiple edge cracks in Euler-Bernoulli beams having two different types of cracks is presented based on energy equations. Each crack is modeled as a massless rotational spring using the Linear Elastic Fracture Mechanics (LEFM) theory, and a relationship among natural frequencies, crack locations and stiffness of equivalent springs is demonstrated. In the procedure, for detection of m cracks in a beam, 3m equations and natural frequencies of healthy and cracked beam in two different directions are needed as input to the algorithm. The main accomplishment of the presented algorithm is the capability to detect the location, severity and type of each crack in a multi-cracked beam. Concise and simple calculations along with accuracy are other advantages of this method. A number of numerical examples for cantilever beams including one and two cracks are presented to validate the method.

Research paper thumbnail of Energy-based procedure for detection of crack in stepped-beam like structures

ABSTRACT In this paper, we presented a simple energy-based procedure for detection a crack in ste... more ABSTRACT In this paper, we presented a simple energy-based procedure for detection a crack in stepped-beam like structures modeled by Euler-Bernoulli beam theory. We modeled the existing crack by a local torsional spring in order to develop energy-based local damage index. We demonstrated a relationship among crack parameters and natural frequencies that it is usable for forward and inverse problems. For detection of the crack in stepped beam, we used first three natural frequencies of beam and presented two different simple methods for solving the related equations: Plotting diagram and numerical calculation. We present the numerical examples for a two-step cantilever beam to validate our method.

Research paper thumbnail of Calculation of Wave Dispersion Curves in Multilayered Composite-Metal Plates

Shock and Vibration, 2014

The major purpose of this paper is the development of wave dispersion curves calculation in multi... more The major purpose of this paper is the development of wave dispersion curves calculation in multilayered composite-metal plates. At first, equations of motion and characteristic equations for the free waves on a single-layered orthotropic plate are presented. Since direction of wave propagation in composite materials is effective on equations of motion and dispersion curves, two different cases are considered: propagation of wave along an axis of material symmetry and along off-axes of material symmetry. Then, presented equations are extended for a multilayered orthotropic composite-metal plate using the transfer matrix method in which a global transfer matrix may be extracted which relates stresses and displacements on the top layer to those on the bottom one. By satisfying appropriate boundary conditions on the outer boundaries, wave characteristic equations and then dispersion curves are obtained. Moreover, presented equations may be applied to other materials such as monoclinic, transversely isotropic, cubic, and isotropic materials. To verify the solution procedure, a number of numerical illustrations for a single-layered orthotropic and double-layered orthotropic-metal are presented.

Research paper thumbnail of Multiple-crack damage detection in multi-step beams by a novel local flexibility-based damage index

Journal of Sound and Vibration, 2013

Research paper thumbnail of Vibration based algorithm for crack detection in cantilever beam containing two different types of cracks

Vibration based algorithm for crack detection in cantilever beam containing two different types of cracks

Journal of Sound and Vibration, 2013

ABSTRACT In this paper, a simple method for detection of multiple edge cracks in Euler-Bernoulli ... more ABSTRACT In this paper, a simple method for detection of multiple edge cracks in Euler-Bernoulli beams having two different types of cracks is presented based on energy equations. Each crack is modeled as a massless rotational spring using the Linear Elastic Fracture Mechanics (LEFM) theory, and a relationship among natural frequencies, crack locations and stiffness of equivalent springs is demonstrated. In the procedure, for detection of m cracks in a beam, 3m equations and natural frequencies of healthy and cracked beam in two different directions are needed as input to the algorithm. The main accomplishment of the presented algorithm is the capability to detect the location, severity and type of each crack in a multi-cracked beam. Concise and simple calculations along with accuracy are other advantages of this method. A number of numerical examples for cantilever beams including one and two cracks are presented to validate the method.

Research paper thumbnail of Energy-based procedure for detection of crack in stepped-beam like structures

ABSTRACT In this paper, we presented a simple energy-based procedure for detection a crack in ste... more ABSTRACT In this paper, we presented a simple energy-based procedure for detection a crack in stepped-beam like structures modeled by Euler-Bernoulli beam theory. We modeled the existing crack by a local torsional spring in order to develop energy-based local damage index. We demonstrated a relationship among crack parameters and natural frequencies that it is usable for forward and inverse problems. For detection of the crack in stepped beam, we used first three natural frequencies of beam and presented two different simple methods for solving the related equations: Plotting diagram and numerical calculation. We present the numerical examples for a two-step cantilever beam to validate our method.