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The dynamic experimental and numerical analysis of cracked beams has been studied with the aim of quantifying the influence of depth crack on the dynamic response of steel beams. Artificial Neural Method ANN has been used where a numerical simulation was improved in Matlab. A finite element model has also been developed by using the Ansys software, and the obtained results were compared with exact crack length. The study takes into account different hidden layer values in order to determine the sensitivity of the predicted crack depth. The results show that the response of the beam (frequencies) is strongly related to the crack depth, which significantly affects the beam behavior, especially when the crack is very deep where the ANN allows us to identify the crack in lower computational time. Based on the provided results, we can detect that the effect of hidden layer size can affect the results.

The dynamic experimental and numerical analysis of cracked beams has been studied with the aim of quantifying the influence of depth crack on the dynamic response of steel beams. Artificial Neural Method ANN has been used where a numerical simulation was improved in Matlab. A finite element model has also been developed by using the Ansys software, and the obtained results were compared with exact crack length. The study takes into account different hidden layer values in order to determine the sensitivity of the predicted crack depth. The results show that the response of the beam (frequencies) is strongly related to the crack depth which significantly affects the beam behavior, especially when the crack is very deep where the ANN allows us to identify the crack in lower computational time. Based on the provided results, we can detect that the effect of hidden layer size can affect the results.

In this study, numerical simulations are carried out to determine the open water performance of the INSEAN E779A marine propeller. On the other hand, modal and harmonic response analysis under hydrodynamic loading are carried out by using unidirectional approach by coupling the ANSYS Mechanical and the ANSYS CFX codes. The finite element model of the propeller has been constructed. By using this model, the dynamic characteristics of the blade have been analysed. The first 12 natural frequencies under nominal operating conditions, and the harmonic response of the exciting fluid pressures, are obtained. During Fluid-Structure Interaction, the flow around the propeller can lead to excitation of the resonance. The calculated open water performances in terms of thrust and torque coefficients correspond very well to the experimental data for a wide range of the advance coefficient. The results obtained show that the operating frequencies of the INSEAN E779A marine propeller are much lower than the resonant frequencies, so resonant conditions are easily avoided. [ABSTRACT FROM AUTHOR]

Flow-induced vibrations are sometimes catastrophic for mechanical structures and constitute an important dimensioning factor. This study is motivated by modelling and numerical simulation of fluid structure interaction phenomena (FSI) goshawks marine propellers. Indeed, in this work, numerical and experimental modal analyses are performed in air and in water. The resolution of this problem is achieved by one-way coupling with ANSYS Mechanical code of structures (CSD, Computational Structure Dynamics) and ANSYS CFX code of fluids (CFD, Computational Fluid Dynamics). This numerical study would not have been possible without Geometric Characterization of the Propeller, accomplished through a digital comparator. For validating and evaluating the FSI simulation, an experimental study is conducted in the laboratory of vibration using a two-channel vibration analyser FFT/DFT type 2035 and subsonic wind tunnel "TE44CH". The experimental tool has allowed finding the variation of the vibration amplitudes as a function of the fluid speed. This predicts the critical inflow speed. The results show the fluid flow importance to the local vibration of the propeller. A comparison of numerical and experimental results is then carried out. [ABSTRACT FROM AUTHOR]

In this paper, a numerical characterization of aluminum honeycomb sandwich panel and experimental validation are proposed. Firstly, numerical homogenization approach to predict the elastic properties of the core only are performed using initial finite element model of Representative Volume Element (RVE) which does not take into account the double thickness wall existing in aluminum core structure. According to these initial parameters, finite element model of sandwich composite plate is constructed to extract its elasto-dynamic characteristics. In order to validate the numerical achievements, Experimental Modal Analysis of sandwich plate was carried out. Secondly, the double thickness wall is selected to be introduced in the RVE because of important error between results, new comparative study validates the improved elastic parameters and illustrate that the double thickness wall play an important role in the homogenization procedure. Furthermore, the influence of the delamination defect on the vibration behavior of the composite panel is investigated using the validated 3-D finite element model. [ABSTRACT FROM AUTHOR]

An original quasi-3D hyperbolic shear deformation theory for simply supported functionally graded plates is proposed in this work. The theory considers both shear deformation and thickness-stretching influences by a hyperbolic distribution of all displacements within the thickness, and respects the stress-free boundary conditions on the upper and lower surfaces of the plate without using any shear correction coefficient. By expressing the shear parts of the in-plane displacements with the integral term, the number of unknowns and equations of motion of the proposed theory is reduced to four as against five in the first shear deformation theory (FSDT) and common quasi-3D theories. Equations of motion are obtained from the Hamilton principle. Analytical solutions for dynamic problems are determined for simply supported plates. Numerical results are presented to check the accuracy of the proposed theory. [ABSTRACT FROM AUTHOR]