Estimation of in-Plane Elastic Parameters and Stiffener Geometry of Stiffened Plates

Identification of Elastic Properties of Stiffened Composite Shell

“…Despite the great variety of literature available on the identification of the elastic constants of laminated plates, there are very few studies dedicated to the problems of the estimation of the elastic parameters of stiffened plates. By S. Chakraborty and M. Mukhopadhyay (Chakraborty et al 2000), the determination of in-plane elastic constants of stiffened plates was performed. In that study, instead of a physical experiment, numerical vibration data were used to determine the elastic constants.…”

Analysis of the sensitivity of a vibration-based procedure for structural identification

“…In order to compare the results obtained with cubic approximation, it is necessary to have 4 5 6 6 20 ⋅ ⋅ = experimental runs. Since in this case the FEM calculations are not very time-consuming, the D-optimal Latin hypercube-type design [2] with N = 70 runs and K = 3 variables has been selected (Fig. 2 To disclose the frequencies existing in the plate, the time integration was carried out with a small step, namely, 0.0001 s. During modeling it became clear that it was necessary to apply an asymmetric impulse load to the structure for excitation of the greatest number of frequencies.…”

“…1 (2) Previous investigations [1] showed that the second-order approximations should be used to construct the approximations f . In this case, the relative error of the approximation is less than 0.03%, which is much smaller than the error of the FEM.…”

“…The method of eigenfrequencies of oscillations is widely used for estimation of structural material properties. The methodology of identification is similar to that described for composite plates in [1][2][3]. According to this method, the eigenfrequencies of structures are measured (by the resonance method and Fourier transformation) and, at the same time, a finite element model (FEM) is developed.…”

Techniques for Identification of Bending and Extensional Elastic Stiffness Matrices on Thin Composite Material Plates Based on Virtual Field Method (VFM): Theoretical and Numerical Aspects

“…The difference among the identification techniques based on these iterative procedures is basically in the way as the optimization problem is formulated, for example, the type of adopted search method to find the minimal, the boundary conditions, the geometric characteristics of the samples, the type of anisotropy of the test material, the type of experimental devices, and the numerical method used to compute the mode shapes (or operational modes) with their respective frequencies (Deobald & Gibson, 1988;Pedersen & Frederiksen, 1992;Lai & Lau, 1993;Ayorinde & Gibson, 1995;Rikards & Chate, 1998;Ayorinde & Yu, 1999Rikards et al, 1999;Bledzki et al, 1999;Hwang & Chang, 2000;Araujo et al, 2000;Chakraborty & Mukhopadhyay, 2000;Rikards et al, 2001;Lauwagie et al, 2003;Lauwagie et al, 2004;Lee & Kam, 2006;Cugnoni et al, 2007;Bruno et al, 2008;Diveyev & Butiter, 2008a, 2008b. In works that do not use iterative process, natural frequencies and mode shapes, or operational frequencies and modes, are input data of an algorithm based on the differential equation that governs the transversal vibration of sample in a specific direction and under specific boundary conditions (Gibson, 2000;Alfano & Pagnotta, 2007).…”