Journal of Modeling in Mechanics and Materials

ISSN: 2512-353X

Topics

Volume 1 Issue 2

July 2017

June 7, 2017

Nonlinear transient and thermal analysis of functionally graded shells using a seven-parameter shell finite element

Miguel Gutierrez Rivera, J. N. Reddy

Article number: 20170003

Abstract

In this paper the thermo-mechanical response of functionally graded plates and shells is studied using a continuum shell finite element model with high-order spectral/hp basis functions. The shell element is based on the seven-parameter first-order shear deformation theory, and it does not utilize reduced integration or stabilization ideas and yet exhibits no locking. The static and dynamic response of functionally graded shells, with power-law variation of the constituents, under mechanical and thermal loads is investigated by varying the volume fraction of the constituents. Numerical results for deflections and stresses are presented and compared with available analytical and finite element results from the literature. The performance of the shell element for transient thermal problems is found to be excellent.

August 14, 2017

A Two-Dimensional Coarse-Grained Model for Molybdenum Disulphide

Cui-Xia Wang, Chao Zhang, T. Rabczuk

Article number: 20170007

Abstract

We parametrize a two-dimensional (2D) coarse-grained (CG) model of molybdenum disulphide (MoS 2 ) with Stillinger Weber (SW) potential in which all SW geometrical parameters are determined analytically from the equilibrium condition for each potential term, while the SW energy parameters are derived analytically based on the valence force field (VFF) model. This parametrization method transfers the accuracy of the VFF model to the SW potential. The uniqueness of the CG model is that the hexagonal lattice symmetry is maintained, and especially, the positions of Mo i beads and S i beads in the CG model are the same as Mo atoms and S atoms, respectively, in the atomic SLMoS 2 , where the subscript i represent the ith order CG level. Owing to its simplicity, the CG model can be used to investigate the adsorption effect on the resonant frequency. We find that the resonant frequency of the oscillation is insensitive to the adsorbed effect.

June 7, 2017

Eringen’s small length scale coefficient for vibration of axially loaded nonlocal Euler beams with elastic end restraints

C. M. Wang, H. Zhang, N. Challamel, W. H. Duan

Article number: 20160158

Abstract

This paper presents the calibration of Eringen’s small length scale coefficient e 0 for elastically restrained beams (in the context of buckling and axially loaded vibration) on the basis of an interesting connection between a discrete beam model (DBM) and the Eringen’s nonlocal beam model (ENBM). The DBM is formulated from the use of the central finite difference method which has been shown to be equivalent to the Hencky bar-chain model. By solving the discrete beam formulation using the theory of linear difference equations and matching the buckling loads and natural frequencies of the DBM with those of the ENBM, the small length scale coefficient e 0 may be calibrated for buckling and vibration beam problems. It is found that by applying the traditional nonlocal continuous boundary conditions, e 0 varies with respect to the boundary conditions. However, e0=1/6${e_0} = 1/\sqrt 6$ for purely free vibration problems while e0=1/12${e_0} = 1/\sqrt {12}$ for buckling problems, irrespective of the boundary conditions, when the continualized discrete boundary conditions are applied. For both traditional continuous and continualized discrete boundary conditions, the value of e 0 is found to be dependent on the axial load.

May 31, 2017

A review on energy harvesting from ocean waves by piezoelectric technology

N. V Viet, N Wu, Q Wang

Article number: 20160161

Abstract

Piezoelectric materials have been widely used to harvest energy from ocean waves. This review is to introduce and review the development of the technologies. First, from comparison of the three major energy conversion techniques namely electrostatic, electromagnetic and piezoelectric technologies, in terms of power generation capability, transmission efficiency, and structural installation and economic costs, the advantages of applying piezoelectric energy conversion technology are identified. Second, the review sums up different methodologies and designs of harvesting energy from ocean waves based on different piezoelectric effects. In particular, the designs and efficiencies of available harvesters based on the piezoelectric effects from longitudinal, bending, and shear couplings are introduced and discussed. Finally, the futuristic research directions and methods for improving the efficiencies of the piezoelectric harvesters are discussed profoundly in this area.

Publicly Available February 15, 2017

Analysis of mechanical properties in bending processes and optimal design of simple tape spring

Hongling Ye, Chunhua Zhao, Yang Zhang, Qi Yao, Yanni Xiao

Article number: 20160156

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Abstract

Tape spring is straight, thin-walled, elastic strip with curved cross-section, which can replace traditional hinges by allowing for folding elastically and unfolded releasing stored energy with fewer component parts. This work is devoted to the properties of the folding and deployment of simple tape spring by numerical simulation and experiment method. Firstly, the folding process of tape spring is experimentally investigated using a specially designed test rig and verified by using nonlinear finite element ABAQUS/Standard solver. Then the moment-rotation relationships for symmetric bending are studied, the effects of subtended angle of section, total tape spring length, thickness and cross section radius on the performance of tape spring are investigated. Furthermore, the optimal model of tape spring structure design is established based on the response surface methodology (RSM) and parameter’s effective analysis, which aims at maximum strain energy during the tape-spring hinge deployment and subjects to allowable stress of tape spring. And the interior point algorithm is used to solve the optimal model. The optimal results are of great importance to the design of novel deployable structures with high stability, reliability and lightweight.

June 8, 2017

Unsteady Boundary Layer Flow and Convective Heat Transfer of a Fluid Particle Suspension with Nanoparticles over a Stretching Surface

B. C. Prasannakumara, B. J. Gireesha, M. R. Krishnamurthy, Rama Subba Reddy Gorla

Article number: 20170002

Abstract

We analyzed the effects of Biot number and non-uniform heat source/sink on boundary layer flow and nonlinear radiative heat transfer of fluid particle suspension over an unsteady stretching surface embedded in a porous medium with nanoparticles. We considered conducting dust particles embedded with -water nanopartcles. The governing equations are transformed into nonlinear ordinary differential equations by using local similarity transformations and solved numerically using Runge–Kutta-Fehlberg-45 order method along with shooting technique. The effects of non-dimensional parameters on velocity and temperature profiles for fluid phase and dust phase are discussed and presented through graphs. Also, friction factor and Nusselt number are discussed and presented through graphs. Comparisons of the present study were made with existing studies under some special assumptions. The present results have an excellent agreement with existing studies. Results indicated that the enhancement in fluid particle interaction parameter increases the heat transfer rate and depreciates the wall friction. Also, radiation parameter has the tendency to increase the temperature profiles of the dusty nanofluid.

Volume 1 (2017)

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Type: Journal
Language: English
Publisher: De Gruyter
First published: March 20, 2017
Last published: July 1, 2017
Publication Frequency: 2 Issues per Year