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Article
Publication date: 12 June 2017

Priyadarshi Biplab Kumar and Dayal R. Parhi

Being an interdisciplinary research area, biomechanics has gained interest among researchers. Biomechanics deals with integration of mechanical phenomenon with the…

Abstract

Purpose

Being an interdisciplinary research area, biomechanics has gained interest among researchers. Biomechanics deals with integration of mechanical phenomenon with the structural and functional aspects of biological systems. Biological systems being very much complex provide a very intricate platform for their analysis. In case of damages created by accidents or sport malfunctions, artificial implants are used for the replacement of bones. These implants may cause incompatibility with the human body, depending on their design and characterization. So, this research aims to analyze the vibrational characteristics of a human femur bone and to predict the safe ranges of frequencies of operation.

Design/methodology/approach

The current research is aimed at vibrational characterization of a human femur bone. The model of the femur bone is prepared using SOLIDWORKS software. The material properties of the femur are collected from the available literature and provided with the CAD model. The model is imported to the ANSYS software. Loading patterns as applied on the human body are also applied to the prepared model. Suitable boundary conditions are chosen for normal sitting and standing positions. The natural frequencies of the femur bone and other vibrational parameters are found out.

Findings

The first data obtained from the ANSYS software are the natural frequencies and mode shapes of vibration. Other data include the stress distributions, strain distributions, deformation patterns and potential zones of damage. The frequencies and mode shapes enable the safe ranges of human operation and the frequency range to be followed in the designing of implants. The stress distributions enable to know the potential zones of damage so that those areas can be given focus during strength considerations.

Research limitations/implications

The current investigations take into account only normal sitting and walking conditions. This work can be included under static loadings. This can also be extended toward dynamic loading conditions. In the dynamic loading, walking and running conditions can be taken into account. This work focuses on the safe designing of the artificial implants and their compatibility with the human body. This can also be extended toward role of dynamic forces in the damaged bone formation and the role of implant’s characteristics for healing of bones.

Practical implications

Bone damage and ligament fracture are common nowadays due to increasing number of accidents, which may be vehicular or sports. In case of any damage to the skeletal parts, some artificial implant is used to support the damaged part and to help in the process of healing. The designing of the implants must be compatible with the human body. The natural frequencies and mode shapes give an idea that the vibrational parameters of the implant material must fall in the same range as the actual bone. The stress distribution and potential zone damage emphasize on strength considerations.

Originality/value

The current method is a novel approach toward implant designing. Here an analysis of vibrational parameters of the human femur bone is performed. Those parameters include natural frequencies, mode shapes, principal normal stress distributions, principal shear stress distributions, maximum shear elastic strains and total deformation. These parameters reflect an idea about behavior of the femur bone under actual loading conditions. This analysis enables an implant designer to focus on material properties and strength considerations of the implants which are to be used in case of bone damage.

Details

World Journal of Engineering, vol. 14 no. 3
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 1 August 1999

Jaroslav Mackerle

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the…

Abstract

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Details

Engineering Computations, vol. 16 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 11 November 2020

Feng Wang, Fangfang Zhang, Qixiang Huang and Mohammad Salmani

The purpose of this paper is to propose a method with capability of short-time implementation.

Abstract

Purpose

The purpose of this paper is to propose a method with capability of short-time implementation.

Design/methodology/approach

This paper was directed using both experimental tests and simulations to propose a comprehensive method for lifetime estimation of the solder joints.

Findings

A new method with good agreement with experimental tests has been proposed.

Originality/value

It is confirmed that paper is original.

Details

Soldering & Surface Mount Technology, vol. 33 no. 3
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 5 September 2016

Feride Akman and Nevin Çankaya

This paper aims to synthesise and characterise N-cyclohexylmethacrylamide (NCMA) monomer which contains thermosensitive group. The characterisation of monomer was…

Abstract

Purpose

This paper aims to synthesise and characterise N-cyclohexylmethacrylamide (NCMA) monomer which contains thermosensitive group. The characterisation of monomer was performed both theoretically and experimentally.

Design/methodology/approach

The monomer was prepared by reacting cyclohexylamine with methacryloyl chloride in the presence of triethylamine at room temperature. The synthesised monomer was characterised by using not only Density Functional Theory (DFT) and Hartree–Fock (HF) with the Gaussian 09 software but also fourier transform infrared (FT–IR), 1H and 13C nuclear magnetic resonance (NMR) spectroscopy.

Findings

Both the experimental and the theoretical methods demonstrated that the monomer was successfully synthesised. The vibrational frequencies, the molecular structural geometry, such as optimised geometric bond angles, bond lengths and the Mulliken atomic charges of NCMA were investigated by using DFT/B3LYP and HF methods with the 3-21G* basis set. The experimental results were compared with theoretical values. The results revealed that the calculated frequencies were in good accord with the experimental values. Besides, frontier molecular orbitals (FMOs) and molecular electrostatic potential of NCMA were investigated by theoretical calculations at the B3LYP/3–21G* basis set.

Research limitations/implications

Monomer and polymer containing a thermosensitive functional group have attracted great interest from both industrial and academic fields. Their characterisation can provide great opportunities for polymer science by using DFT and HF methods.

Originality/value

The monomer containing a thermosensitive functional group and a various polymer may be prepared by using DFT and HF methods described in this paper. The calculated data are greatly important to provide insight into molecular analysis and then used in technological applications.

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Article
Publication date: 11 April 2021

Esra Barim and Feride Akman

This study aimed the synthesis and theoretical/experimental characterization of novel benzofuran-based acrylamide monomer.

Abstract

Purpose

This study aimed the synthesis and theoretical/experimental characterization of novel benzofuran-based acrylamide monomer.

Design/methodology/approach

Novel N-substituted acrylamide monomer, i.e. N-[2–(4-Bromo-benzoyl)-benzofuran-3-yl]-acrylamide (BBFA), was synthesized by reacting (3-Amino-benzofuran-2-yl)-(4-bromophenyl) methanone with acryloylchloride at 0–5oC. Nuclear magnetic resonance (1H-NMR), infrared (FT-IR) and UV-Visible spectrophotometer were used to elucidate the chemical structure of BBFA. Computational studies were performed using the DFT (B3LYP) method on the basis of 6-31 + G (d, p) using Gaussian 09 W and Gauss View 5.0 package in addition to the VEDA program, gauge-independent atomic orbital (GIAO) and time-dependent density functional theory (TD-DFT) methods.

Findings

Molecular geometry and vibration assignments of the BBFA monomer were calculated. The molecular structure of the monomer was examined. Both longest and shortest bonds were determined in the structure. The nucleophilic and electrophilic regions of the monomer were determined. The theoretical spectroscopic data of the monomer were compared with the experimental data; both were consistent with each other. The chemical reactivity of the monomer was also determined.

Originality/value

The synthesized BBFA monomer can be evaluated in many areas; from medicine to industry (such as textiles) owing to the presence of various active functional groups. Indeed, acrylamide copolymers are remarkable materials for polymer science and industry. The data produced in this study is original and adds to the scientific community.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 16 March 2015

Andrew Katz, Justin Nussbaum, Craig P Lusk and Nathan B Crane

The purpose of this paper is to evaluate the use of a simple printed geometry to estimate mechanical properties (elastic modulus, yield strength) with inexpensive test…

Abstract

Purpose

The purpose of this paper is to evaluate the use of a simple printed geometry to estimate mechanical properties (elastic modulus, yield strength) with inexpensive test equipment.

Design/methodology/approach

Test geometry is presented that enables controlled strains with manual deformation and repeatable measurement of vibrational frequencies. This is tested with multiple fused deposition modeling (FDM) machines to assess measurement accuracy and repeatability. Printing orientation and some printing parameters are varied to assess the measurement sensitivity.

Findings

The test methods show good correlation with manufacturer material specifications in the X-Y plane and reported elastic strain limits. It is also sensitive to printing orientation and printing parameters.

Research limitations/implications

Further work is needed to assess the sensitivity of the method to particular defects and parameter errors expected in particular applications.

Originality/value

This method supports process monitoring in production environments and inexpensive assessments of material properties for hobbyist and do-i- yourself users. While it is tested with FDM, it should be applicable to other additive manufacturing processes.

Details

Rapid Prototyping Journal, vol. 21 no. 2
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 June 1997

Jaroslav Mackerle

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…

Abstract

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Details

Engineering Computations, vol. 14 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 11 February 2019

Soheil Oveissi, Davood Toghraie, S. Ali Eftekhari and Ali J. Chamkha

This study aims to study the transverse vibration and instabilities of the fluid-conveying single-walled carbon nanotubes (CNTs). To this purpose, the Euler–Bernoulli beam…

Abstract

Purpose

This study aims to study the transverse vibration and instabilities of the fluid-conveying single-walled carbon nanotubes (CNTs). To this purpose, the Euler–Bernoulli beam model is used. Also, the surface effects, small-size effects of the both fluid and structure and two different elastic mediums viscoelastic and Pasternak elastic are investigated.

Design/methodology/approach

To consider the nano-scale for the CNT, the strain-inertia gradient theory is used and to solve the governing equation of motion for the system, the Galerkin’s method is used. The effect of the flow velocity, aspect ratio, characteristic lengths of the mentioned theory, effects of Knudsen number and effects of the Winkler, the Pasternak elastic and the viscoelastic medium on the frequencies and stabilities of the system are studied. The effects of the above parameters on the vibrational behavior are investigated both separately and simultaneously.

Findings

The results show that the critical flow velocity value is increased as the aspect ratio, characteristic lengths, Winkler modulus, shear and damping factors increase. Also, the critical flow velocity is increased by considering the surface effects. In addition, the consequence of increase in the nano-flow-size effects (Knudsen number) is decreasing the critical flow velocity. Moreover, it can be observed that the effect of the shear factor on increasing the critical flow velocity is different from the rest of parameters.

Originality/value

Use of Timoshenko and modified couple stress theories and taking into account Von-Karman expressions for investigating the nonlinear vibrations of triple-walled CNTs buried within Pasternak foundation.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 4
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 5 June 2020

Manisha Maity, Santimoy Kundu, Raju Kumhar and Shishir Gupta

This mathematical analysis has been accomplished for the purpose of understanding the propagation behaviour like phase velocity and attenuation of Love-type waves through…

Abstract

Purpose

This mathematical analysis has been accomplished for the purpose of understanding the propagation behaviour like phase velocity and attenuation of Love-type waves through visco-micropolar composite Earth’s structure.

Design/methodology/approach

The considered geometry of this problem involves a micropolar Voigt-type viscoelastic stratum imperfectly bonded to a heterogeneous Voigt-type viscoelastic substratum. With the aid of governing equations of motion of each individual medium and method of separation of variable, the components of micro-rotation and displacement have been obtained.

Findings

The boundary conditions of the presumed geometry at the free surface and at the interface, together with the obtained components of micro-rotation, displacement and mechanical stresses give rise to the determinant form of the dispersion relation. Moreover, some noteworthy cases have also been extrapolated in detail. Graphical interpretation irradiating the impact of viscoelasticity, micropolarity, heterogeneity and imperfectness on the phase velocity and attenuation of Love-type waves is the principal highlight of the present study.

Practical implications

In this study, the influence of the considered parameters such as micropolarity, viscoelasticity, heterogeneity, and imperfectness has been elucidated graphically on the phase velocity and attenuation of Love-type waves. It has been noticed from the graphs that with the rising magnitude of micropolarity and heterogeneity, the attenuation curves shift upwards, that is the loss of energy of these waves takes place in a rapid way. Hence, from the outcomes of the present analysis, it can be concluded that heterogeneous micropolar stratified media can serve as a helpful tool in increasing the attenuation or in other words, loss of energy of Love-type waves, thus reducing the devastating behaviour of these waves.

Originality/value

Till date, the mathematical modelling as well as vibrational analysis of Love-type waves in a viscoelastic substrate overloaded by visco-micropolar composite Earth’s structure with mechanical interfacial imperfection remain unattempted by researchers round the globe. The current analysis is an approach for studying the traversal traits of surface waves (here, Love-type waves) in a realistic stratified model of the Earth’s crust and may thus, serves as a dynamic paraphernalia in various domains like earthquake and geotechnical engineering; exploration geology and soil mechanics and many more, both in a conceptual as well as pragmatic manner.

Details

Engineering Computations, vol. 37 no. 9
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 May 1998

Chin‐Hsu Lin

The paper presents a method for the more accurate solution of C0 acoustic vibration problems in finite element (FE) analysis by postprocessing. For each frequency, the…

Abstract

The paper presents a method for the more accurate solution of C0 acoustic vibration problems in finite element (FE) analysis by postprocessing. For each frequency, the method uses the computed eigenvector and the Helmholtz equation to calculate gradients of dependent variables at element centers. Gradients at element centers are then used as sampling points in a patch recovery technique to obtain gradients at nodes. The nodal primary field and its gradients are used to interpolate the dependent variables over each element. This interpolation yields the potential and kinetic energies of each element, and hence a Rayleigh quotient that provides an accurate eigenvalue. One‐, two‐ and three‐dimensional vibration problems are used as numerical examples.

Details

Engineering Computations, vol. 15 no. 3
Type: Research Article
ISSN: 0264-4401

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