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M. R. Banan

Bio: M. R. Banan is an academic researcher from Shiraz University. The author has contributed to research in topics: Finite element method & Estimation theory. The author has an hindex of 11, co-authored 31 publications receiving 658 citations. Previous affiliations of M. R. Banan include University of Illinois at Urbana–Champaign.

Papers
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Journal ArticleDOI
TL;DR: In this article, two algorithms are proposed for estimating member constitutive properties of a finite-element model with known geometry and topology from measured displacements under a known static loading.
Abstract: Two algorithms are proposed for estimating member constitutive properties of a finite-element model with known geometry and topology from measured displacements under a known static loading. The proposed algorithms are based on the concept of minimizing an index of discrepancy between the model and the measurements, the first using the error in nodal forces and the second using the error in displacements at the measurement sites. The problem is set up as a constrained least-squares minimization and is solved with the recursive quadratic programming method. Both estimators are capable of making estimates with spatially incomplete measurements, and both are amendable to the modeling of complex structures.

184 citations

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TL;DR: In this article, the behavior of a force-error estimator and a displacement-error estimation using Monte Carlo simulation and a bowstring truss as the model problem is studied.
Abstract: The behavior is studied of a force-error estimator and a displacement-error estimator using Monte Carlo simulation and a bowstring truss as the model problem. The most important factors governing the performance of any parameter-estimation algorithm are the quality and quantity of measured data. To assess the performance of the force-error estimator and the displacement-error estimator, we examine their behavior with respect to the amount of noise in the measurements, the spatial distribution of measurements, the number of spatial measurements, the number of load cases, and the character of load cases (specifically, loading patterns). In addition to the extensive study of the effects of the physical character of the data and the experiment, we examine the effects of different starting values of the unknown parameters used to initiate the iteration.

145 citations

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TL;DR: In this paper, the thermal buckling and postbuckling analysis of laminated composite beams with temperature-dependent material properties is presented, where the governing equations are based on first-order shear deformation beam theory (FSDT) and the geometrical nonlinearity is modeled using Green's strain tensor in conjunction with the von Karman assumptions.
Abstract: The thermal buckling and postbuckling analysis of laminated composite beams with temperature-dependent material properties is presented. The governing equations are based on the first-order shear deformation beam theory (FSDT) and the geometrical nonlinearity is modeled using Green's strain tensor in conjunction with the von Karman assumptions. The differential quadrature method (DQM) as an accurate, simple and computationally efficient numerical tool is adopted to discretize the governing equations and the related boundary conditions. A direct iterative method is employed to obtain the critical temperature (bifurcation point) as well as the nonlinear equilibrium path (the postbuckling behavior) of symmetrically laminated beams. The applicability, rapid rate of convergence and high accuracy of the method are established via different examples and by comparing the results with those of existing in literature. Then, the effects of temperature dependence of the material properties, boundary conditions, length-to-thickness ratios, number of layers and ply angle on the thermal buckling and postbuckling characteristic of symmetrically laminated beams are investigated.

68 citations

Journal ArticleDOI
TL;DR: In this paper, a time-domain equation error estimator for estimating the constitutive parameters of a complex linear structure is proposed, which can accommodate response sampled incompletely in time, state and space and is amenable to identification of complex structural systems.
Abstract: The authors propose a time-domain equation error estimator for the problem of estimating the constitutive parameters of a complex linear structure. From a mathematical model with known geometry, topology, load history, and responses at certain locations, a parameter estimation problem evolves that, when solved, determines the unknown constitutive parameters of that model. First, the authors estimate the displacement and velocity at the locations where accelerations have been measured by standard integration/filtering techniques. Next, the equations of motion are recast and established as a discrete multistep method in regards to displacements at the unmeasured degrees of freedom and weighted sum of residual forces at adjacent time points. Finally, the unknown constitutive parameters are estimated by solving a constrained nonlinear optimization problem, assuming the parameter estimate to be an average of estimates over several time intervals. The recursive quadratic programming method is the preferred method to solve the optimization problem. The proposed time-domain estimator can accommodate response sampled incompletely in time, state, and space and is amenable to identification of complex structural systems.

57 citations

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TL;DR: In this article, the role of temperature dependence of material properties on the thermal postbuckling behavior of laminated composite skew plates has been investigated, and the plate governing equations are based on first-order shear deformation theory (FSDT) and the geometrical nonlinearity is modeled using Green's strain tensor in conjunction with the von Karman assumptions.
Abstract: Thermal postbuckling and consequently, the role of temperature dependence of material properties on the thermal postbuckling behavior of laminated composite skew plates have not been addressed in literature. Hence, this problem is investigated here. The plate governing equations are based on the first-order shear deformation theory (FSDT) and the geometrical nonlinearity is modeled using Green’s strain tensor in conjunction with the von Karman assumptions. Since the problem is geometrically and physically nonlinear, the differential quadrature method (DQM) as an accurate, simple and computationally efficient numerical tool is adopted to discretize the governing equations and the related boundary conditions. Then, a direct iterative method is employed to obtain the critical temperature (bifurcation point) and consequently the nonlinear equilibrium path (the postbuckling behavior) of symmetrically laminated skew plates. After validating the formulation and the method of solution, the effects of temperature dependence of the material properties on the postbuckling characteristic of laminated skew plates with different skew angle, boundary conditions, length-to-thickness ratio, number of layers and ply layout are investigated.

44 citations


Cited by
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TL;DR: In this paper, the authors present the results of a health monitoring study, carried out during the destructive load testing of a prototype reinforced concrete (RC) bridge, which represented a popular class of road bridges in which regular health monitoring is a very important issue during the service life.
Abstract: This paper presents the results of a health monitoring study, carried out during the destructive load testing of a prototype reinforced concrete (RC) bridge. The bridge was made up of cement-concrete reinforced with steel rods, and represented a popular class of road bridges in which regular health monitoring is a very important issue during the service life. The bridge was instrumented with piezoceramic transducer (PZT) patches, which were electrically excited at high frequencies, of the order of kHz, and the real part of admittance (conductance) was extracted as a function of the exciting frequency. The patches were scanned for the acquisition of this signature at various stages during the loading process. The signatures of the patches located in the vicinity of the damage were found to have undergone drastic changes, while those farther away were less affected. Damage was quantified in non-parametric terms using the root mean square of the deviation in signatures with respect to the baseline signature of the healthy state. This non-parametric index was found to correlate well with the damage progression in the structure.

366 citations

Journal ArticleDOI
TL;DR: In this article, the problem of structural damage detection is formulated as an optimization problem, which is then solved by using genetic algorithm (GA), which is able to detect the approximate location of the damage, even when practical considerations limit the number of on-site measurements to only a few.

332 citations

Journal ArticleDOI
TL;DR: The electromechanical impedance (EMI) technique, which employs piezoelectricceramic leadzirconatetitarate (PZT) patches as impedance transducers, has emerged as a powerful non-destructive evaluation.
Abstract: The electromechanical impedance (EMI) technique, which employs piezoelectricceramic leadzirconatetitarate (PZT) patches as impedance transducers, has emerged as a powerful nondestructive evaluation...

276 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented the results of an experimental study for the detection and characterization of damages using PZT transducers on aluminum specimens, which was adopted for damage detection.
Abstract: The detection of damages by modal analysis and similar vibration techniques depends upon the knowledge and estimation of various modal parameters. In addition to the associated difficulties, such low-frequency dynamic response based techniques fail to detect incipient damages. Smart piezoelectric ceramic (PZT) transducers, which act both as actuators and sensors in a self-analyzing manner, are emerging to be effective in non-parametric health monitoring of structural systems. In this paper we present the results of an experimental study for the detection and characterization of damages using PZT transducers on aluminum specimens. The method of extracting the impedance characteristics of the PZT transducer, which is electromechanically coupled to the host structure, is adopted for damage detection. Three types of damage are simulated and assessed by the bonded PZT transducers for characterization. We present the effectiveness of PZT transducers in the detection and characterization of incipient damages without the need to know the modal parameters. The PZT transducers are found to have a significantly large sensing area for detecting even small incipient damages. The possibility of replicating the pristine state signatures of different transducers under similar conditions of bonding and geometrical location is also explored. For appropriate characterization of damages, a few statistical signature pattern recognition techniques are evaluated.

242 citations

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TL;DR: In this paper, a neural-network-based control algorithm has been developed and tested in the computer simulation of active control of a three-story frame structure subjected to ground excitations.
Abstract: A new neural-network-based control algorithm has been developed and tested in the computer simulation of active control of a three-story frame structure subjected to ground excitations. First, an emulator neural network has been trained to forecast the future response of the structure from the immediate history of the system's response, which consists of the structure plus an actuator. The trained emulator has been used in predicting the future responses and in evaluating the sensitivities of the control signal with respect to those responses. At each time step of the simulation, the control signal has been adjusted to induce the required control force in the actuator based in a control criterion. A controller neural network has been trained to learn the relation between the immediate history of response of the structure and actuator, and the adjusted control signals. The trained neurocontroller has been used in controlling the structure for different dynamic loading conditions. Results of this initial st...

231 citations