Dynamic analysis and wave propagation in rotating heterogeneous cylinders under moving load and thermal conditions; implementing an efficient mesh free method

Purpose – The purpose of this paper is to propose a hybrid mesh-free method based on generalized finite difference (GFD) and Newmark finite difference methods to study the elastic wave propagation in functionally graded nanocomposite reinforced by carbon nanotubes (FGNRCN). The presented hybrid mesh-free method is applied for a thick hollow cylinder, which is made of FGNRCN and excited by various mechanical shock loadings. Design/methodology/approach – The FG nanocomposite cylinder is assumed to be under shock loading. The elastic wave propagation is obtained and studied for various nonlinear grading patterns and distributions of the aligned carbon nanotubes. The distribution of carbon naotubes in FG nanocomposite are considered to vary as nonlinear function of radius, which varies with various nonlinear grading patterns continuously through radial direction. The effective material properties of functionally graded carbon nanotube are estimated using a micro-mechanical model. Findings – The mechanical shock analysis of FGNRCN thick hollow cylinder is carried out and the dynamic behavior of displacement field and the time history of radial displacement are obtained for various grading patterns. An effective hybrid mesh-free method based on GFD and Newmark finite difference methods is presented to calculate the average velocity of elastic wave propagation in FGNRCN. The average velocity of elastic wave propagation is obtained for various grading patterns and various kinds of volume fraction. The effects of some parameters on average velocity of elastic wave propagation are obtained and studied in detail. Originality/value – The calculation of elastic radial wave propagation in a FGNRCN thick hollow cylinder is presented using a hybrid mesh-free method. The effects of some parameters on wave propagation such as various grading patterns of distribution of carbon nanotubes are studied in details.

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A mesh-free method with arbitrary-order accuracy for acoustic wave propagation

Computers & Geosciences ◽

10.1016/j.cageo.2015.02.006 ◽

2015 ◽

Vol 78 ◽

pp. 15-25 ◽

Cited By ~ 20

Author(s):

Junichi Takekawa ◽

Hitoshi Mikada ◽

Naoto Imamura

Keyword(s):

Wave Propagation ◽

Acoustic Wave ◽

Arbitrary Order ◽

Acoustic Wave Propagation ◽

Order Accuracy ◽

Mesh Free ◽

Mesh Free Method

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An absorbing boundary condition for acoustic-wave propagation using a mesh-free method

Geophysics ◽

10.1190/geo2015-0315.1 ◽

2016 ◽

Vol 81 (4) ◽

pp. T145-T154 ◽

Cited By ~ 14

Author(s):

Junichi Takekawa ◽

Hitoshi Mikada

Keyword(s):

Boundary Condition ◽

Wave Propagation ◽

Acoustic Wave ◽

Boundary Conditions ◽

Absorbing Boundary Conditions ◽

Absorbing Boundary Condition ◽

Acoustic Wave Propagation ◽

Absorbing Boundary ◽

Mesh Free ◽

Mesh Free Method

We have developed an absorbing boundary condition for acoustic-wave propagation using a mesh-free method without sacrificing the flexibility of the mesh-free framework. When we simulate acoustic-wave propagation using a numerical method, artificial reflections from model edges induced by a truncated computational domain should be avoided. Although many absorbing boundary conditions have been developed, most of them have been based on a regular latticed alignment of grids or nodes, and the efficiency of such absorbing boundary conditions for irregular arrangement of grids or nodes has not been examined yet. We have studied the artificial reflections generated at the boundaries of a model for a mesh-free method, and we have proposed a novel approach for suppressing the artifacts. The method uses a hybrid approach with a transition zone, in which the wavefield is estimated by a weighted average of solutions from the one- and two-way wave equations. Numerical experiments indicate that the proposed method can provide good performance in suppression of the artificial edge reflections even for irregular distributions of calculation points in the vicinity of model edges.

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DYNAMIC RESPONSE OF FUNCTIONALLY GRADED NANOCOMPOSITE BEAMS SUBJECTED TO A MOVING LOAD USING A MESH-FREE METHOD

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2017-518 ◽

2017 ◽

Vol 41 (5) ◽

pp. 884-899

Author(s):

Alireza Sayyidmousavi ◽

Mehrdad Foroutan ◽

Habiba Bougherara ◽

Zouheir Fawaz

Keyword(s):

Dynamic Response ◽

Moving Load ◽

Matrix Material ◽

Theory Of Elasticity ◽

Current Approach ◽

Functionally Graded ◽

Design Parameters ◽

Mesh Free ◽

Mesh Free Method ◽

Distribution Type

In this paper, the dynamic response of functionally graded nanocomposite beams under the action of a moving load are investigated. Three different types of Carbon NanoTubes (CNT’s) distributions in a polymer matrix material are studied; Uniform Distribution (UD), Symmetrically Functionally Graded (SFG) distribution and Unsymmetrically Functionally Graded (USFG) distribution. The analysis is carried out by a mesh-free method using the two-dimensional theory of elasticity. After validation, the effects of different design parameters such as CNT’s distribution, the velocity and position of the moving load on the dynamic behavior of the beam are examined. The results also highlight the importance of the reinforcement distribution type from a design perspective. The current approach can serve as a benchmark against which other semi-analytical and numerical methods based on classical beam theories can be compared.

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