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Article
Publication date: 10 June 2014

Stylianos K. Georgantzinos, Georgios I. Giannopoulos and Nick K. Anifantis

The purpose of this paper is to examine the potential of single-walled carbon nanotubes as mass sensors by developing analytical expressions and then comparing the outcome…

Abstract

Purpose

The purpose of this paper is to examine the potential of single-walled carbon nanotubes as mass sensors by developing analytical expressions and then comparing the outcome with structural mechanics corresponding predictions.

Design/methodology/approach

The carbon nanotube (CNT) resonators are assumed to be either single or double clamped. Analytical formulas capable of describing the vibrational behavior of such CNT-based nanoresonators with an attached mass at nanotube tip or various intermediate positions are developed by combining the Euler–Bernoulli theory and Krylov–Duncan functions.

Findings

The validity and the accuracy of these formulas are examined for a wide range of cases via comparisons with corresponding results arisen by spring- or beam-based structural mechanics predictions. Both structural mechanics approaches utilize three-dimensional nanoscale elements formulated according to the molecular theory. The results indicate that the new sensor equations may be utilized for the estimation of vibration response of CNT-based mass sensors with reasonable accuracy.

Originality/value

Simple analytical formulas are proved to approximate the mass sensing ability of CNTs adequately, the fact that may significantly contribute in the effort of developing new sensor devices.

Details

Sensor Review, vol. 34 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Abstract

Details

International Journal of Structural Integrity, vol. 8 no. 6
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 1 February 2005

Shutian Liu, Haipeng Jia and Delun Wang

Usually, an optimal topology is obtained by optimizing the material distribution within a prescribed domain; for example, a rectangular domain with a specified length and…

Abstract

Usually, an optimal topology is obtained by optimizing the material distribution within a prescribed domain; for example, a rectangular domain with a specified length and width for a plane problem. However, the dimensions (i.e. aspect ratio) of a rectangular design domain have significant influence on the resultant optimal topology. In this paper, a minimum Averaged Compliance Density (ACD) based method for topology optimization of structures is proposed. Unlike the conventional topology optimization method, the ACD is taken as the objective function, and the topology and domain dimensions of the structure are optimized simultaneously. As an example, the topology of a cantilever beam with large aspect ratio will be optimized, which is often difficult for traditional topology optimization algorithms. Through optimizing the topology and the dimensions of the design domain, a base structure is obtained, which is repeated to yield the whole, assembled beam. The influence of the relative values of shear force and moment is analyzed numerically. Results show that as the value of the bending moment increases relative to the shear force, the optimal topology changes from a truss‐like structure to a vertically stiffened box‐like structure.

Details

Multidiscipline Modeling in Materials and Structures, vol. 1 no. 2
Type: Research Article
ISSN: 1573-6105

Keywords

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Article
Publication date: 3 July 2017

Zheyuan Zheng and Zhaoxia Li

This paper aims to introduce a multiscale computational method for structural failure analysis with inheriting simulation of moving trans-scale boundary (MTB). This method…

Abstract

Purpose

This paper aims to introduce a multiscale computational method for structural failure analysis with inheriting simulation of moving trans-scale boundary (MTB). This method is motivated from the error in domain bridging caused by cross-scale damage evolution, which is common in structural failure induced by damage accumulation.

Design/methodology/approach

Within the method, vulnerable regions with high stress level are described by continuum damage mechanics, while elastic structural theory is sufficient for the rest, dividing the structural model into two scale domains. The two domains are bridged to generate mixed dimensional finite element equation of the whole system. Inheriting simulation is developed to make the computation of MTB sustainable.

Findings

Numerical tests of a notched three-point bending beam and a steel frame show that this MTB method can improve efficiency and ensure accuracy while capturing the effect of material damage on deterioration of components and structure.

Originality/value

The proposed MTB method with inheriting simulation is an extension of multiscale simulation to structural failure analysis. Most importantly, it can deal with cross-scale damage evolution and improve computation efficiency significantly.

Details

Engineering Computations, vol. 34 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 April 2006

Qing Hua, Jiang He‐fu, Wen Wei‐dong and Wu Chang‐bo

In this paper, a turbine blade was optimized by multidisciplinary design optimization (MDO) method. This turbine blade optimization is based on the optimization frame…

Abstract

In this paper, a turbine blade was optimized by multidisciplinary design optimization (MDO) method. This turbine blade optimization is based on the optimization frame software iSIGHT, in which four disciplines (aerodynamics, thermal dynamics, structural mechanics and structural dynamics) have been integrated. Two commercial discipline analysis soft wares, NUMECA and ANSYS, are coupled in the platform iSIGHT. The three dimensional (3‐D) model of a blade was firstly parameterized. And then a set of parameters are chosen to optimize the blade to obtain the better overall properties. The result shows that the overall performances of the turbine blade have been improved remarkably after it is optimized by using the MDO method.

Details

Multidiscipline Modeling in Materials and Structures, vol. 2 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

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Article
Publication date: 1 June 1992

KJELL MAGNE MATHISEN and PÅL G. BERGAN

This paper discusses algorithms for large displacement analysis of interconnected flexible and rigid multibody systems. Hydrostatic and hydrodynamic loads for systems…

Abstract

This paper discusses algorithms for large displacement analysis of interconnected flexible and rigid multibody systems. Hydrostatic and hydrodynamic loads for systems being submerged in water are also considered. The systems may consist of cables and beams and may combine very flexible parts with rigid parts. Various ways of introducing structural joints are discussed. A special implementation of the Hilber‐Hughes‐Taylor time integration scheme for constrained non‐linear systems is outlined. The formulation is general and allows for displacements and rotational motion of unlimited size. Aspects concerning efficient solution of constrained dynamic problems are discussed. These capabilities have been implemented in a general purpose non‐linear finite element program. Applications involving static and dynamic analysis of a bi‐articulated tower and a floating tripod platform kept in place by three anchor lines are discussed.

Details

Engineering Computations, vol. 9 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 February 2000

Richard Friedrich

This bibliography contains references to papers, conference proceedings, theses and books dealing with finite strip, finite prism and finite layer analysis of structures…

Abstract

This bibliography contains references to papers, conference proceedings, theses and books dealing with finite strip, finite prism and finite layer analysis of structures, materially and/or geometrically linear or non‐linear.

Details

Engineering Computations, vol. 17 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 January 1987

P. Thoft‐Christensen and J.D. Sørensen

Structural optimisation and reliability theory are considered, and described. A general reliability‐based structural optimisation problem is formulated, and consideration…

Abstract

Structural optimisation and reliability theory are considered, and described. A general reliability‐based structural optimisation problem is formulated, and consideration given to procedures for solving it. Two different examples suggest the efficacy of these procedures. The amount of calculations depends to a great degree on the definition of failure of the structure. In order to reduce this by improving optimisation procedures, more research is needed, and the convergence of the optimisation is very dependent on accurate evaluation of the gradients of the reliability constraints.

Details

International Journal of Quality & Reliability Management, vol. 4 no. 1
Type: Research Article
ISSN: 0265-671X

Keywords

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Article
Publication date: 9 April 2020

Dragan D. Milašinović, Petar Marić, Žarko Živanov and Miroslav Hajduković

The problems of inelastic instability (buckling) and dynamic instability (resonance) have been the subject of extensive investigation and have received wide attention from…

Abstract

Purpose

The problems of inelastic instability (buckling) and dynamic instability (resonance) have been the subject of extensive investigation and have received wide attention from the structural mechanics community. This paper aims to tackle these problems in thin-walled structures, taking into account geometrical and/or material non-linearity.

Design/methodology/approach

The inelastic buckling mode interactions and resonance instabilities of prismatic thin-walled columns are analysed by implementing the semi-analytical finite strip method (FSM). A scalar damage parameter is implemented in conjunction with a material modelling named rheological-dynamical analogy to address stiffness reduction induced by the fatigue damage.

Findings

Inelastic buckling stresses lag behind the elastic buckling stresses across all modes, which is a consequence of the viscoelastic behaviour of materials. Because of the lag, the same column length does not always correspond to the same mode at the elastic and inelastic critical stress.

Originality/value

This paper presents the influence of mode interactions on the effective stresses and resonance instabilities in thin-walled columns due to the fatigue damage. These mode interactions have a great influence on damage variables because of the fatigue and effective stresses around mode transitions. In its usual semi-analytical form, the FSM cannot be used to solve the mode interaction problem explained in this paper, because this technique ignores the important influence of interaction of the buckling modes when applied only for undamaged state of structure

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Article
Publication date: 5 September 2018

Snehashish Chakraverty and Nisha Rani Mahato

In structural mechanics, systems with damping factor get converted to nonlinear eigenvalue problems (NEPs), namely, quadratic eigenvalue problems. Generally, the…

Abstract

Purpose

In structural mechanics, systems with damping factor get converted to nonlinear eigenvalue problems (NEPs), namely, quadratic eigenvalue problems. Generally, the parameters of NEPs are considered as crisp values but because of errors in measurement, observation or maintenance-induced errors, the parameters may have uncertain bounds of values, and such uncertain bounds may be considered in terms of closed intervals. As such, this paper aims to deal with solving nonlinear interval eigenvalue problems (NIEPs) with respect to damped spring-mass systems having interval parameters.

Design/methodology/approach

Two methods, namely, linear sufficient regularity perturbation (LSRP) and direct sufficient regularity perturbation (DSRP), have been proposed for solving NIEPs based on sufficient regularity perturbation method for intervals. LSRP may be used for solving NIEPs by linearizing the eigenvalue problems into generalized interval eigenvalue problems, and DSRP may be considered as a direct solution procedure for solving NIEPs.

Findings

LSRP and DSRP methods help in computing the lower and upper eigenvalue and eigenvector bounds for NIEPs which contain the crisp eigenvalues. Further, the DSRP method is computationally efficient compared to LSRP.

Originality/value

The efficiency of the proposed methods has been validated by example problems of NIEPs. Moreover, the procedures may be extended for other nonlinear interval eigenvalue application problems.

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