Element Diffusion and Material Properties in Transition Layer of Bending Zone in Laminated Plates

2016 ◽  
Vol 43 (7) ◽  
pp. 0702001
Author(s):  
张攀 Zhang Pan ◽  
王续跃 Wang Xuyue
Keyword(s):  
Material Properties ◽  
Transition Layer ◽  
Laminated Plates ◽  
Element Diffusion

Prediction of elastic properties of carbon nanotube reinforced composites

2005 ◽  
Vol 461 (2058) ◽  
pp. 1685-1710 ◽  
Author(s):  
N Hu ◽  
H Fukunaga ◽  
C Lu ◽  
M Kameyama ◽  
B Yan
Keyword(s):  
Finite Element ◽  
Carbon Nanotube ◽  
Molecular Mechanics ◽  
Elastic Properties ◽  
Polymer Matrix ◽  
Material Properties ◽  
Transition Layer ◽  
Beam Model ◽  
Reinforced Composites ◽  
Computational Structural Mechanics

In this paper, the macroscopic elastic properties of carbon nanotube reinforced composites are evaluated through analysing the elastic deformation of a representative volume element (RVE) under various loading conditions. This RVE contains three components, i.e. a carbon nanotube, a transition layer between the nanotube and polymer matrix and an outer polymer matrix body. First, based on the force field theory of molecular mechanics and computational structural mechanics, an equivalent beam model is constructed to model the carbon nanotube effectively. The explicit relationships between the material properties of the equivalent beam element and the force constants have been set-up. Second, to describe the interaction between the nanotube and the outer polymer matrix at the level of atoms, the molecular mechanics and molecular dynamics computations have been performed to obtain the thickness and material properties of the transition layer. Moreover, an efficient three-dimensional eight-noded brick finite element is employed to model the transition layer and the outer polymer matrix. The macroscopic behaviours of the RVE can then be evaluated through the traditional finite element method. In the numerical simulations, the influences of various important factors, such as the stiffness of transition layer and geometry of RVE, on the final macroscopic material properties of composites have been investigated in detail.

Reflection of elastic waves from a linear transition layer

1966 ◽  
Vol 56 (2) ◽  
pp. 511-526
Author(s):  
Ravindra N. Gupta
Keyword(s):  
Plane Wave ◽  
Material Properties ◽  
Transition Layer ◽  
Elastic Waves ◽  
Wave Reflection ◽  
Reflection Coefficients ◽  
Angle Of Incidence ◽  
Arbitrary Angle ◽  
S Wave ◽  
Incidence Plane

abstract A separation of P- and S-wave potentials is achieved for an inhomogeneous medium in which density is constant and Lame's parameters, λ and μ, are assumed to vary as λ/λ1 = μ/μ1 = (1 + bz)2 where λ1, μ1 and b are constants. The resulting equations are solved for an arbitrary angle of incidence. Plane wave reflection coefficients are obtained for the situation when the material mentioned above forms a transition layer between two homogeneous, elastic half-spaces. First and/or second-order discontinuities in material properties are permitted at the boundaries of the transition layer. Some numerical results are given.

scholarly journals Prediction and Measurement of the Damping Ratios of Laminated Polymer Composite Plates

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3370
Author(s):  
Hugo Sol ◽  
Hubert Rahier ◽  
Jun Gu
Keyword(s):  
Material Properties ◽  
Single Layer ◽  
Composite Plates ◽  
Laminated Plates ◽  
Secondary Importance ◽  
Reinforced Composite ◽  
Composites Materials ◽  
Modal Damping ◽  
Resonance Frequencies ◽  
Subsequent Step

Laminated composites materials are mostly used in dynamically loaded structures. The design of these structures with finite element packages is focused on vibrations, elastic deformations and failure control. Damping is often neglected because of its assumed secondary importance and also because of dearth of information on relevant material properties. This trend is prone to change as it is now realised that damping plays an increasingly important role in vibration comfort, noise radiation and crash simulations. This paper shows in a first step how to identify the orthotropic elastic and damping properties of single layer fibre-reinforced composite material sheets using a new extended version of the Resonalyser procedure. The procedure is based on the elastic-viscoelastic correspondence principle and uses a mixed numerical experimental method. In a subsequent step, the complex laminate stiffness values are computed using the identified single layer material properties. To validate this approach, the modal damping ratios of arbitrary laminated plates of different materials at several resonance frequencies are predicted and experimentally verified.

Vibration analysis of axially moving line supported functionally graded plates with temperature-dependent properties

2013 ◽  
Vol 228 (6) ◽  
pp. 953-969 ◽  
Author(s):  
Hamed Asadi ◽  
Mohammad M Aghdam ◽  
Mahmoud Shakeri
Keyword(s):  
Dynamic Analysis ◽  
Material Properties ◽  
Vibration Analysis ◽  
Volume Fraction ◽  
Functionally Graded ◽  
Laminated Plates ◽  
Functionally Graded Plates ◽  
Temperature Dependent ◽  
Axially Moving ◽  
Temperature Dependent Properties

Vibration analysis of axially moving functionally graded plates with internal line supports and temperature-dependent properties is investigated using harmonic differential quadrature method. The plate is subjected to static in-plane forces while out-of-plane loading is dynamic. Stability of an axially moving plate, traveling at a constant velocity between different supports and experiencing small transverse vibrations are considered. The series of internal rigid line supports parallel to the plate edges are considered together with various arbitrary combinations of boundary conditions. Material properties of the plate are assumed temperature-dependent which is a non-linear function of temperature and differ continuously through thickness according to a power-law distribution of the volume fractions of the plate constituents. Two types of micromechanical models, namely, the Voigt and Mori–Tanaka models are considered. Based on the classical plate theory, the governing equations are obtained for functionally graded plate using the Hamilton’s principle. In the frame of a general dynamic analysis, it is shown that the onset of instability takes place in the form of divergence. The plate may experience divergence or flutter instability at a super critical velocity. Results for dynamic analysis of isotropic and laminated plates are validated with available data in the existing literature, which show excellent agreement. Furthermore, some new results are presented for vibration analysis of functionally graded material plates to study effects of the location of line supports, material properties, volume fraction, temperature, loading, aspect ratio and speed.

Stochastic Finite Element Buckling Analysis of Laminated Plates With Circular Cutout Under Uniaxial Compression

2006 ◽  
Vol 74 (4) ◽  
pp. 798-809 ◽  
Author(s):  
A. K. Onkar ◽  
C. S. Upadhyay ◽  
D. Yadav
Keyword(s):  
Material Properties ◽  
Perturbation Technique ◽  
Compressive Loading ◽  
Laminated Composite ◽  
Composite Plates ◽  
Buckling Analysis ◽  
Laminated Plates ◽  
Buckling Strength ◽  
The Mean ◽  
Random Material Properties

A generalized stochastic buckling analysis of laminated composite plates, with and without centrally located circular cutouts having random material properties, is presented under uniaxial compressive loading. In this analysis, the layerwise plate model is used to solve both prebuckling and buckling problems. The stochastic analysis is done based on mean centered first-order perturbation technique. The mean buckling strength of composite plates is validated with results available in the literature. It has been observed that the present analysis can predict buckling load accurately even for plates with large cutouts. Micromechanics based approach is used to study the effect of variation in microlevel constituents on the effective macrolevel properties like elastic moduli. Consequently, the effect of uncertainty in these material properties on the buckling strength of the laminated plates is studied. Parametric studies are carried out to see the effect of hole size, layups, and boundary conditions on the mean and variance of plate buckling strength.

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