Search results for "Rayleigh-Ritz"
showing 5 items of 5 documents
Thermo-mechanical post-buckling analysis of variable angle tow composite plate assemblies
2017
peer-reviewed The increasing use of composite materials for lightweight structural applications and the extended tailoring capabilities offered by variable stiffness laminates requires rapid and robust analysis tools that adequately describe the mechanical behaviour of such structures. In this work, a Rayleigh–Ritz solution for generally restrained multilayered stiffened variable angle tow plates in the post-buckling regime is presented. The plate model is based on first-order shear deformation theory and accounts for geometrical nonlinearity through von Kármán’s assumptions. General symmetric and unsymmetric stacking sequences are considered and Legendre orthogonal polynomials are employed…
An extended Ritz formulation for buckling and post-buckling analysis of cracked multilayered plates
2018
Abstract An extended Ritz formulation for the analysis of buckling and post-buckling behaviour of cracked composite multilayered plates is presented. The formulation is based on: (i) the First-order Shear Deformation Theory to model the mechanics of the multilayered plate; (ii) the von Karman’s theory to account for geometric non-linearities ; (iii) the use of an extended set of approximating functions able to model the presence of an embedded or edge crack and to capture the crack opening fields as well as the global behaviour within a single cracked domain. The numerical results of the buckling analyses and the equilibrium paths in the post-buckling regime are compared with the results fr…
A Rayleigh-Ritz approach for postbuckling analysis of variable angle tow composite stiffened panels
2018
Abstract A Rayleigh-Ritz solution approach for generally restrained multilayered variable angle tow stiffened plates in postbuckling regime is presented. The plate model is based on the first order shear deformation theory and accounts for geometrical nonlinearity through the von Karman’s assumptions. Stiffened plates are modelled as assembly of plate-like elements and penalty techniques are used to join the elements in the assembled structure and to apply the kinematical boundary conditions. General symmetric and unsymmetric stacking sequences are considered and Legendre orthogonal polynomials are employed to build the trial functions. A computer code was developed to implement the propose…
Vibration-based identification of mechanical properties of orthotropic arbitrarily shaped plates: Numerical and experimental assessment
2018
Abstract An innovative procedure is introduced for the identification of the mechanical parameters of orthotropic plates of arbitrary shape, under various boundary conditions, based on vibration data. The method employs a combination of a convenient Rayleigh-Ritz approach and Particle-Swarm Optimization to estimate elastic constants of the orthotropic material in a straightforward manner, without requiring computationally demanding iterative Finite Element analyses. Specifically, the pb-2 Rayleigh-Ritz procedure is extended and applied to deal with orthotropic plates, simplifying the approach to more easily treat generic plate shapes, taking advantage of the Green's theorem. The method is t…
Optimization of Passive Constrained Layer Damping (Pcld) Treatments for Vibration Reduction
2015
An efficient method to reduce the frequency averaged transverse vibration level of aplate by optimizing the position of attached passive constrained layer damping PCLD is presented.This method uses a multilayer anisotropic plate model which is an equivalent single layer platemodel (ESL) where transverse shear stresses and displacements are continuous at each layer’sinterfaces. Hence, for a laminate composed of an arbitrary number of layers, all the quantities arerelated to those of the first layer. The optimization process is based on the use of the ESL platemodel combined with the genetic algorithm (GA) and Latin Hypercube Sampling (LHS) algorithmimplemented in a Rayleigh-Ritz resolution p…