Search results for "SPAZI"
showing 10 items of 630 documents
Boundary Element Method for Composite Laminates
2017
The boundary element method (BEM) is a numerical technique to solve engineering/physical problems formulated in terms of boundary integral equations. Composite laminates are assemblages of stacked different materials layers, generally consisting of variously oriented fibrous composite materials
Magneto-Electro-Elastic Bimorph Analysis by the Boundary Element Method
2008
The influence of the magnetic configuration on the behavior of magneto-electro-elastic bimorph beams is analyzed by using a boundary element approach. The problem is formulated by using the generalized displacements and generalized tractions. The boundary integral equation formulation is obtained by extending the reciprocity theorem to magneto-electro-elastic problems; it is numerically implemented by using the boundary element method multidomain technique to address problems involving nonhomogeneous configurations. Results under different magnetic configurations are compared highlighting the characteristic features of magnetopiezoelectric behavior particularly focusing on the link between …
Large deflection of magneto-electro-elastic laminated plates
2014
Abstract A model for the large deflection analysis of magneto-electro-elastic laminated plates is derived. The first order shear deformation theory and the von Karman stress function approach are employed. A set of resolving partial differential equations involving kinematical variables and the stress function is obtained as a consequence of the preliminary condensation of the electro-magnetic state to the plate kinematics. A closed form solution for simply-supported plates is presented. Numerical results are carried out for plates consisting of piezoelectric BaTiO 3 and piezomagnetic CoFe 2 O 4 layers. These results show the influence of large deflections on the plate response and could be…
Onthe repeatability of electromechanical impedance for monitoring of bonded joints
2015
The repeatability and sensitivity of the electromechanical impedance (EMI) method when employed for the structural health monitoring of bonded joints were investigated. A simple joint was assembled by bonding an aluminum strip to a square aluminum plate. Two rounds of experiments were performed. The first set aimed at verifying the repeatability of the method. The joint was monitored by using one piezoelectric sensor. The PZT was glued to the plate and never removed, whereas a poorly bonded joint was assembled and disassembled three times. For each case, the electromechanical signature was measured during the curing of the adhesive. After the three tests, the same joint was built with a dif…
Numerical analysis of a piezoelectric structural health monitoring system for composite flange-skin delamination detection
2013
Abstract In this paper, a piezoelectric based Structural Health Monitoring (SHM) system is proposed to detect skin/stiffener debonding and delamination cracks proper of laminated composite structures. The SHM system is analyzed by means of a boundary element code implemented in the framework of piezoelectricity. The multidomain technique, coupled with an interface spring model, is used to model laminated composite structures as well as the bonding between the host delaminated structure and the piezoelectric sensor. Static sensitivity analyses are firstly performed on a drop-ply delaminated structure in order to identify a suitable configuration for the sensor. Then, the dynamic electromecha…
Electroelastic Analysis of Piezoelectric Composite Laminates by Boundary Integral Equations
2004
A boundary integral representation for the electroelastic state in piezoelectric composite laminates subjected to axial extension, bending, torsion, shear/bending, and electric loadings is proposed. The governing equations are presented in terms of electromechanical generalized variables by the use of a suitable matrix notation. Thus, the three-dimensional electroelasticity solution for piezoelectric composite laminates is generated from a set of two partially coupled differential equations defined on the cross section of each individual ply within the laminate. These ply equations are linked through the interface conditions, which allow restoration of the model of the laminate as a whole. …
A fast 3D dual boundary element method based on hierarchical matrices
2008
AbstractIn this paper a fast solver for three-dimensional BEM and DBEM is developed. The technique is based on the use of hierarchical matrices for the representation of the collocation matrix and uses a preconditioned GMRES for the solution of the algebraic system of equations. The preconditioner is built exploiting the hierarchical arithmetic and taking full advantage of the hierarchical format. Special algorithms are developed to deal with crack problems within the context of DBEM. The structure of DBEM matrices has been efficiently exploited and it has been demonstrated that, since the cracks form only small parts of the whole structure, the use of hierarchical matrices can be particula…
Advances in Fracture and Damage Mechanics XII
2014
The proceedings contain 170 papers. The topics discussed include: structural integrity of a shaft subjected to multiaxial fatigue loads in presence of short crack; blunt cracks and two parameter fracture criteria; flexural and shear capacity evaluation of reinforced ultra-high strength concrete members with steel rebars; evolution of shear localization in an elasto-plastic cosserat material under shearing; experimental soil - concrete plate interaction test and numerical models; modeling microstructural effects on the mechanical behavior of a friction stirred channel aluminum alloy; nonlinear thermo-mechanical coupled modeling for the analysis of stress distribution in air-plasma-sprayed th…
A four-node MITC finite element for magneto-electro-elastic multilayered plates
2013
An isoparametric four-node finite element for multilayered magneto-electro-elastic plates analysis is presented. It is based on an equivalent single-layer model, which assumes the first order shear deformation theory and quasi-static behavior for the electric and magnetic fields. First, the electro-magnetic state of the plate is determined in terms of the mechanical primary variables, namely the generalized displacements, by solving the strong form of the magneto-electric governing equations coupled with the electro-magnetic interface continuity conditions and the external boundary conditions. In turn, this result is used into the layers constitutive law to infer the equivalent single-layer…
A finite element formulation for large deflection of multilayered magneto-electro-elastic plates
2014
An original finite element formulation for the analysis of large deflections in magneto-electro-elastic multilayered plates is presented. The formulation is based on an equivalent single-layer model in which first order shear deformation theory with von Karman strains and quasi-static behavior for the electric and magnetic fields are assumed. To obtain the plate model, the electro-magnetic state is firstly determined and condensed to the mechanical primary variables, namely the generalized displacements. In turn, this result is used to obtain laminate effective stiffness coefficients that allow to express the plate mechanical stress resultants in terms of the generalized displacements and a…