Layer-wise finite-element analysis of a functionally graded hollow thick cylinder with a piezoelectric ring

Author(s):  
M H Yas ◽  
M Shakeri ◽  
M Khanjani

In this work, a layer-wise finite-element formulation is developed for the analysis of a functionally graded material (FGM) hollow thick cylinder with one piezoactuator ring. The cylinder and ring is divided into many sublayers in the thickness direction and the full layer-wise shell theory is used to model a discretely stiffened FGM cylinder. In this model, the displacements are approximated linearly through each mathematical layer. This accounts for any discontinuities in the derivatives of the displacement at the interface of the ring and the cylindrical thick shell. This formulation is derived from the virtual work statement which includes the total structural potential energy and the electrical potential energy of the piezoelectric ring. Assembling stiffness and mass matrices, at each interface between two elements, stress and displacement continuity are forced, and then the finite-element model is solved. Static and dynamic responses of a functionally graded thick cylinder to electrical and mechanical loads with different exponent ‘ n’ of FGM are determined to show the significant influence of the material in homogeneity. The results obtained at a distance far from the ring are compared with the mechanical behaviour of an FGM cylindrical shell without a ring. Because of the Saint Venant effects, the piezoelectrically induced deformation of the shell is confined to a region close to the piezoelectric ring; thus agreements between these two results are observed.

Author(s):  
Wei Yang ◽  
Jyhwen Wang

A generalized analytical solution of mechanical and thermal induced stresses in a multi-layer composite cylinder is presented. Based on the compatibility condition at the interfaces, an explicit solution of mechanical stress due to inner and outer surface pressures and thermal stress due to temperature change is derived. A finite element model is also developed to provide the comparison with the analytical solution. It was found that the analytical solutions are in good agreement with finite element analysis result. The analytical solution shows the non-linear dependency of thermal stress on the diameters, thicknesses and the material properties of the layers. It is also shown that the radial and circumferential thermal stresses depend linearly on the coefficients of thermal expansion of the materials and the temperature change. As demonstrated, this solution can also be applied to analyze the thermo-mechanical behavior of pipes coated with functionally graded materials.


2007 ◽  
Vol 23 (2) ◽  
pp. 159-172
Author(s):  
S.-S. Chen ◽  
W.-C. Hsu

AbstractA soil-structure system associated with a semi-infinite structure such as tunnel or pavement is usually investigated by finite element analysis. If the boundary of the finite element model selected is not far enough from the excitation source or does not have an appropriate energy-absorption mechanism, it may introduce a significant error induced by reflected waves. This study develops a structural transmitting boundary to absorb the transmitting energy at the boundary of the analytical model. The structure is divided into finite and semi-infinite regions. The stiffness of the semi-infinite region is established by the principle of virtual work and applied at the transmitting boundary. The comparisons of the structural displacements induced by vertical harmonic excitations show that the analytical model size can be significantly reduced, if the proposed transmitting boundary is used to simulate the semi-infinite structural region.


2016 ◽  
Vol 28 (2) ◽  
pp. 272-289 ◽  
Author(s):  
Mohammadreza Saviz

A layer-wise finite element approach is adopted to analyse the hollow cylindrical shell made of functionally graded material with piezoelectric rings as sensor/actuator, under dynamic load. The mechanical properties of the substrate are regulated by volume fraction as a function of radial coordinate. The thickness of functionally graded material shell and piezo-rings is divided into mathematical sub-layers and then the general layer-wise laminate theory is formulated through introducing piecewise continuous approximations across the thickness, accounting for any discontinuity in derivatives of the displacement at the interface between the ring and cylinder. The virtual work statement including structural and electrical potential energies yields the three-dimensional governing equations which are reduced to two-dimensional differential equations, using layer-wise method. For axisymmetric case, the resulted equations are solved with one-dimensional finite element method in the axial direction. By assembling stiffness and mass matrices, the required stress and displacement continuities at each interface and between the two adjacent elements are forced. The results for free vibration and static loading are applied to study the convergence and verified by comparing them to solutions of similar existing problems. The induced deformation by piezoelectric actuators as well as the effect of rings on functionally graded material shell is investigated.


1997 ◽  
Vol 50 (11S) ◽  
pp. S216-S224 ◽  
Author(s):  
Luis E. Sua´rez ◽  
Arsalan Shokooh ◽  
Jose´ Arroyo

This paper presents a finite element formulation for the modeling of beams and frames with artificial damping provided by means of a constrained single layer of damping material. The behavior of the damping material is described using the fractional derivative model of viscoelasticity. In this model, the first order derivatives of the strains in the constitutive equations of the viscoelastic materials are replaced by derivatives of order α < 1. The finite element model developed is a one-dimensional beam element with three degrees of freedom per node. The dynamic response is calculated with a procedure involving a transformation of the original equations of motion to the state space and its decoupling with the eigenvectors of a special eigenvalue problem. The accuracy of the modal properties obtained with the beam model is compared with those calculated from a more elaborate plane stress finite element model. It was found that the proposed beam element provides very accurate results and with much lower computational costs than the 2-D model.


2011 ◽  
Vol 482 ◽  
pp. 57-65 ◽  
Author(s):  
Marina Fazzini ◽  
Olivier Dalverny ◽  
Sébastien Mistou

The aim of this work is to identify parameters driving constitutive equations of materials with displacement field measurements carried out by image stereo-correlation during an unidirectional tensile test. We evaluate two identification techniques. The first one is the virtual fields method which consists in writing the principle of virtual work with particular virtual fields. It is generally used in the case of linear elasticity and it requires a perfect knowledge of the model in terms of boundary condition since the virtual fields used must be kinematically admissible. This method allows to determine parameters by a direct and fast calculation, without iterations. The second method is the finite element model updating method. It consists in finding constitutive parameters that achieve the best match between finite element analysis quantities and their experimental counterparts. This method is more adaptable than the virtual field method but it needs to spend more calculation time.


2004 ◽  
Vol 31 (3) ◽  
pp. 440-452 ◽  
Author(s):  
Ilian Zinoviev ◽  
Magdi Mohareb

A methodology for the analysis and design of laterally unsupported portal frames is proposed. A finite element model is developed to predict the elastic critical load and associated buckling mode. Regression analysis is then conducted to find lateral displacement and rotation field expressions that closely approximate the buckled configurations predicted by the finite element analysis. The obtained functions are then substituted into the total potential energy expression, and the stationarity conditions are evoked. The resulting eigen-value problem is solved for the out-of-plane buckling loads that are then compared with those based on the finite element model. The agreement between the two solutions provides an indication of the accuracy of the simplified energy solution. The member destabilizing effects induced by axial forces are separated from those induced by strong axis bending. The separation of these two effects is subsequently exploited in a two-step eigen-value procedure, aimed at determining the key member resistances defined in the interaction check of the standard CSA-S16-01, while accurately modeling the boundary conditions of the member. These are (i) compressive resistance of the member in the absence of bending effects and (ii) flexural resistance of the member in the absence of axial force effects.Key words: portal frames, lateral buckling, finite element analysis, wide flange sections, frame design, principle of stationary potential energy.


2011 ◽  
Vol 11 (01) ◽  
pp. 101-125 ◽  
Author(s):  
C. H. CHEN ◽  
C. I. OU

To determine its actual dynamic responses under the wind loads, modal identification from the field tests was carried out for the Kao Ping Hsi cable-stayed bridge in southern Taiwan. The dynamic characteristics of the bridge identified by a continuous wavelet transform algorithm are compared with those obtained by the finite element analysis. The finite element model was then modified and refined based on the field test results. The results obtained from the updated finite element model were shown to agree well with the field identified results for the first few modes in the vertical, transverse, and torsional directions. This has the indication that a rational finite element model has been established for the bridge. With the refined finite element model, a nonlinear analysis in time domain is employed to determine the buffeting response of the bridge. Through validation of the results against those obtained by the frequency domain approach, it is confirmed that the time domain approach adopted herein is applicable for the buffeting analysis of cable-stayed bridges.


2012 ◽  
Vol 594-597 ◽  
pp. 908-913
Author(s):  
Xi Ping Sun ◽  
Zhen Yu Zhu ◽  
Bing Hao Zhao

The project intends to construct steel pipe piles on both sides of trestle wharf, and the soil vibrations caused by piling construction might have an important effect on the safe service of wharf. In this paper, the dynamic signals during piling construction were recorded and recognized by NExT-ERA. Meanwhile, modal analysis through finite element model of wharf was performed. Through a comparative analysis of the two results, the first two orders of frequency for wharf were obtained. The results would lay foundation for further analysis of dynamic responses of wharf when pile locations close to wharf.


Author(s):  
Deren Ma ◽  
Hamid Lankarani

Abstract Computer models of the human body are robust tools for gaining insight into the gross motion of ground vehicle or aircraft occupants and evaluating the loads and deformations of their critical parts. The knowledge of occupant responses will help in the determination of the type and probable causes of injuries that may be sustained during a crash. One important aspect in crash analysis is how the large motion of the relatively rigid segments of an occupant, such as the limbs, and the small deformations of flexible segments, such as the spine column, are inter-related. To this end, a general methodology for kineto-static analysis of multibody systems with flexible structures undergoing large motion and complicated structural deformations is developed. Rigid multibody dynamics is used to predict the gross motions and displacements at the boundaries. Finite element analysis is then performed to determine the corresponding loads and deformations of the entire structure. Based on this methodology, a multibody model of the occupant with a finite element model of the lumbar spine is developed for a Hybrid II (Part 572) anthropomorphic test dummy. The analytical results obtained from the code are correlated with the experimental results from the impact sled tests. Comparison of the results has shown much closer match between the analyses and the experiments.


2022 ◽  
pp. 107754632110564
Author(s):  
Nuruzzama M Khan ◽  
R Suresh Kumar

This study is aimed at incorporating the zig-zag effect by Murakami zig-zag function in the development of a finite element model for active constraining layer damping treatment of functionally graded sandwich plates. The present sandwich construction consists of functionally graded facings distanced by a ceramic core. The substrate functionally graded plate is subjected to active constraining layer damping treatment, which in itself is a two-layered material system comprised of a viscoelastic layer and a 1–3 piezoelectric composite layer. The deformation kinematics of the functionally graded sandwich plate active constraining layer damping system is shaped using Murakami zig-zag function , and the finite element model is obtained by the virtual work principle. A standard feedback control system has been implemented, and a MATLAB subroutine has been developed to present the open- and closed-loop responses. Substrate plates with functionally graded configurations 1-1-1, 1-2-1, and 2-1-2 are considered to evaluate the effect of active constraining layer damping on damping the frequency responses of these plates. Investigation on damping performance has been carried out, bearing in mind the change in power-law index with top and bottom ceramic-/metal-rich surfaces. Also, the effect of variation in fiber orientation angle (obliquely reinforced) of the piezoelectric composite material on the active constraining layer damping performance has been examined thoroughly.


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