Search results for "Mechanical Engineering & Transports"

Complex power distribution analysis in plates covered with passive constrained layer damping patches

2012

International audience; The vibration of a plate partially covered with a passive constrained layer damping (PCLD) patch is studied from an energetic point of view. The damped plate is excited by an acoustic plane wave. The study is done with a numerical two-dimensional multilayer plate model. Results of the present model are compared to those obtained with three-dimensional finite element models. It is shown that the present model gives accurate results, even for the layer's inner behavior. It is less expansive in terms of computational cost; hence, it can simulate efficiently the structure for higher frequencies. Mathematical formulas for complex mechanical power are presented, and the li…

A class of shear deformable isotropic elastic plates with parametrically variable warping shapes

2017

A homogeneous shear deformable isotropic elastic plate model is addressed in which the normal transverse fibers are allowed to rotate and to warp in a physically consistent manner specified by a fixed value of a real non-negative warping parameter ω. On letting ω vary continuously (at fixed load and boundary conditions), a continuous family of shear deformable plates Pω is generated, which spans from the Kirchhoff plate at the lower limit ω=0, to the Mindlin plate at the upper limit ω=∞; for ω=2, Pω identifies with the third-order Reddy plate. The boundary-value problem for the generic plate Pω is addressed in the case of quasi-static loads, for which a principle of minimum total potential …

Arbitrarily shaped plates analysis via Line Element-Less Method (LEM)

2018

Abstract An innovative procedure is introduced for the analysis of arbitrarily shaped thin plates with various boundary conditions and under generic transverse loading conditions. Framed into Line Element-less Method, a truly meshfree method, this novel approach yields the solution in terms of the deflection function in a straightforward manner, without resorting to any discretization, neither in the domain nor on the boundary. Specifically, expressing the deflection function through a series expansion in terms of harmonic polynomials, it is shown that the proposed method requires only the evaluation of line integrals along the boundary parametric equation. Further, minimization of appropri…

Evolutionary Algorithms and Metaheuristics : Applications in Engineering Design and Optimization

2018

Improving accuracy of FIR filters for computing convolution transforms for smooth non-bandlimited signals

2019

We propose to improve the accuracy of FIR filters for computing convolution transforms for smooth non-bandlimited (NBL) signals by designing filters by the identification method with using a pair of bandlimited portions of the chosen NBL input and output signals related with each other by the given transform. A design example of type IV linear phase differentiator is presented, where filter coefficients are calculated from the bandlimited portions of the Cauchy pulse and its derivative. The performance of the designed differentiator is evaluated by comparing the accuracy of computed derivatives for several smooth NBL test signals, such as the Cauchy pulse, the Hilbert transform of Cauchy pu…

Numerical modelling of the tensile behaviour of BFRCM strips

2019

This paper aims at investigating the tensile behaviour of basalt fibres on cementitious matrix for the strengthening of masonry structures. The use of Basalt Fibre Reinforced Cementitious Matrix (BFRCM) is favourably considered by the scientific community because it represents a natural composite material with high compatibility with stone and masonry substrate. The study is developed through the generation of Finite Element (FE) models capable of reproducing the tensile behaviour of BFRCM strips with different number of layers of grid. For the scope, the micro-modelling approach is adopted assuming different levels of detail for the simulation of the interface constitutive behaviour. Fibre…

A bending theory of thermoelastic diffusion plates based on Green-Naghdi theory

2017

Abstract This article is concerned with bending plate theory for thermoelastic diffusion materials under Green-Naghdi theory. First, we present the basic equations which characterize the bending of thin thermoelastic diffusion plates for type II and III models. The theory allows for the effect of transverse shear deformation without any shear correction factor, and permits the propagation of waves at a finite speed without energy dissipation for type II model and with energy dissipation for type III model. By the semigroup theory of linear operators, we prove the well-posedness of the both models and the asymptotic behavior of the solutions of type III model. For unbounded plate of type III…

Power-Laws hereditariness of biomimetic ceramics for cranioplasty neurosurgery

2019

Abstract We discuss the hereditary behavior of hydroxyapatite-based composites used for cranioplasty surgery in the context of material isotropy. We classify mixtures of collagen and hydroxiapatite composites as biomimetic ceramic composites with hereditary properties modeled by fractional-order calculus. We assume isotropy of the biomimetic ceramic is assumed and provide thermodynamic of restrictions for the material parameters. We exploit the proposed formulation of the fractional-order isotropic hereditariness further by means of a novel mechanical hierarchy corresponding exactly to the three-dimensional fractional-order constitutive model introduced.

Fundamental solutions for general anisotropic multi-field materials based on spherical harmonics expansions

2016

Abstract A unified method to evaluate the fundamental solutions for generally anisotropic multi-field materials is presented. Based on the relation between the Rayleigh expansion and the three-dimensional Fourier representation of a homogenous partial differential operator, the proposed technique allows to obtain the fundamental solutions and their derivatives up to the desired order as convergent series of spherical harmonics. For a given material, the coefficients of the series are computed only once, and the derivatives of the fundamental solutions are obtained without any term-by-term differentiation, making the proposed approach attractive for boundary integral formulations and efficie…

Tensile behaviour of anti-symmetric CFRP composite

2011

Abstract This paper addresses the response of a 17-ply anti-symmetric carbon/epoxy composite subjected to uniaxial tensile loading. Hashin ply damage model is adopted to describe the damage behaviour of the plies, whereas damage initiation and progression of the interfaces are characterised by mixed-mode cohesive damage model. Force-displacement curves obtained numerically and experimentally show good agreement. Results show that all laminae and interfaces experience the damage except laminae with 0o fibre. In addition, damage is concentrated at the tab and central regions of the tensile specimen. Edge delamination is observed in all interfaces.