Xie-Fei Ding, Lin Zhan, Hui-Feng Xi and Heng Xiao
A direct and unified approach is proposed toward simultaneously simulating large strain elastic behaviors of gellan gels with different gellan polymer concentrations. The purpose…
Abstract
Purpose
A direct and unified approach is proposed toward simultaneously simulating large strain elastic behaviors of gellan gels with different gellan polymer concentrations. The purpose of this paper is to construct an elastic potential with certain parameters of direct physical meanings, based on well-designed invariants of Hencky’s logarithmic strain.
Design/methodology/approach
For each given value of the concentration, the values of the parameters incorporated may be determined in the sense of achieving accurate agreement with large strain uniaxial extension and compression data. By means of a new interpolating technique, each parameter as a function of the concentration is then obtained from a given set of parameter values for certain concentration values.
Findings
Then, the effects of gellan polymer concentrations on large strain elastic behaviors of gellan gels are studied in demonstrating how each parameter relies on the concentration. Plane-strain (simple shear) responses are also presented for gellan gels with different polymer concentrations.
Originality/value
A direct, unified approach was proposed toward achieving a simultaneous simulation of large elastic strain behaviors of gellan gels for different gellan polymer concentrations. Each parameter incorporated in the proposed elastic potential will be derived as a function of the polymer concentration in an explicit form, in the very sense of simultaneously simulating large strain data for different concentrations.
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Heng Xiao, Zi-Tao Li, Lin Zhan and Si-Yu Wang
The purpose of this study is to show how gradual strength degradation of metal beams under cyclic bending up to fatigue failure is simulated based on a new elastoplasticity model…
Abstract
Purpose
The purpose of this study is to show how gradual strength degradation of metal beams under cyclic bending up to fatigue failure is simulated based on a new elastoplasticity model free of any yield criterion.
Design/methodology/approach
A new approach is proposed toward accurately and explicitly prescribing evolution of non-uniform stress distribution on beam cross-section under cyclic bending and, as such, gradual degradation of the bending strength can be directly determined.
Findings
Explicit results for the bending response in a whole cyclic process up to fatigue failure are obtained and the fatigue characteristic curve is for the first time simulated directly between the curvature amplitude and the cycle number to failure.
Originality/value
First, explicit and accurate determination of the non-uniform stress distribution on beam cross-section is achieved with asymptotic softening effects. Second, degradation of the bending strength can be directly deduced cycle by cycle. Finally, the relationship between the bending moment and the curvature is calculated using new and efficient numerical algorithms, thus bypassing usual time-consuming calculations with finite element procedures. Numerical results are presented and in good agreement with experimental data.
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Heng Xiao, Wei-Hao Yan, Lin Zhan and Si-Yu Wang
A new and explicit form of the elastic strain-energy function for modeling large strain elastic responses of soft solids is constructed based on Hencky's logarithmic strain tensor.
Abstract
Purpose
A new and explicit form of the elastic strain-energy function for modeling large strain elastic responses of soft solids is constructed based on Hencky's logarithmic strain tensor.
Design/methodology/approach
Well-designed invariants of the Hencky strain are introduced for characterizing deformation modes and, furthermore, a new interpolating technique is proposed for combining piecewise splines into a single smooth function.
Findings
With this new form and this new technique, objectives in three respects may be achieved for the first time.
Originality/value
First, no adjustable parameters need to be treated. Second, large strain responses for three benchmark modes are derivable in a decoupled sense without involving strongly nonlinear coupling effects. Finally, large strain data may be automatically and accurately matched for three benchmark modes, including uniaxial, equi-biaxial and plane-strain extension. Numerical examples are presented and compared with usual approaches.
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José-Antonio Corral-Marfil and Gemma Cànoves-Valiente
The proceedings of the 17 editions of the conference of the Spanish Association of Scientific Experts in Tourism constitute a valuable archival resource within the research on…
Abstract
The proceedings of the 17 editions of the conference of the Spanish Association of Scientific Experts in Tourism constitute a valuable archival resource within the research on Spanish tourism. But so far their contents have not been analyzed. The aim of this chapter is to examine the research that has been presented at its conference by means of a bibliometric analysis of the proceedings of 17 editions. The study focuses on the origin of the research (countries, regions, institutions, and authors), as well as its characteristics in terms of themes dealt with, geographical areas researched, methodologies, disciplinary areas, and attitudes toward tourism. Implications for the evolution of the research are discussed in terms of knowledge contributions and the shaping of major tourism research traditions.
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Quan-Pu Liu, Jia Kang, Long-Xu Tan, Si-Yu Wang, Otto Bruhns and Heng Xiao
This paper aims to present a direct analysis to demonstrate why markedly different tensile and compressive behaviors of concretes could not be simulated with the Drucker–Prager…
Abstract
Purpose
This paper aims to present a direct analysis to demonstrate why markedly different tensile and compressive behaviors of concretes could not be simulated with the Drucker–Prager yield criterion.
Design/methodology/approach
This study proposed an extended form of the latter for establishing a new elastoplasticity model with evolving yield strengths.
Findings
Explicit closed-form solutions to non-symmetric tensile and compressive responses of uniaxial specimens at finite strain are for the first time obtained from hardening to softening.
Originality/value
With such exact solutions, the yield strengths in tension and compression can be explicitly prescribed by uniaxial tensile and compressive stress-strain functions. Then, the latter two are further provided in explicit forms toward accurately simulating tensile and compressive behaviors. Numerical examples are supplied for meso-scale heterogeneous concrete (MSHC) and high-performance concrete (HPC), etc. Model predictions are in good agreement with test data.
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Blanca A. Camargo, Tazim Jamal and Erica Wilson
Pressing sustainability issues face the 21st century, as identified by the Millennium Development Goals and its post initiatives, and ethical principles related to fairness…
Abstract
Pressing sustainability issues face the 21st century, as identified by the Millennium Development Goals and its post initiatives, and ethical principles related to fairness, equity, and justice are increasingly important to address climate change and resource scarcities. Yet, such ethical dimensions remain surprisingly little addressed in the tourism literature. Ecofeminist critique offers insights into this gap, identifying historical antecedents in patriarchal, Enlightenment-driven discourses of science where positivistic approaches facilitate the control and use of nature and women. This chapter draws from this critique to propose a preliminary, justice-oriented framework to resituate sustainable tourism within an embodied paradigm that covers intangibles such as emotions, feelings, and an ethic of care.
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This chapter explores the potential for and value of imagining a humanist paradigm for tourism studies. It explores how the idea of a “paradigm” in tourism can be conceptualized…
Abstract
This chapter explores the potential for and value of imagining a humanist paradigm for tourism studies. It explores how the idea of a “paradigm” in tourism can be conceptualized, arguing that dominant thoughtlines in other fields regarding the meaning of a paradigm are not sufficient for making sense of this idea in the context of tourism studies. The chapter introduces humanism as a philosophical position in the academy and as a lived cultural practice, explores examples of extant work in tourism studies that might be seen to provide the seeds of a humanist paradigm, and offers reflections on the value of imagining such a paradigm for our field.
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Richard Ek and Mekonnen Tesfahuney
In the Western thought tradition, the tourist has not been a subject worthy of intellectual musings and philosophical deliberations. Indeed, the tourist has been portrayed in…
Abstract
In the Western thought tradition, the tourist has not been a subject worthy of intellectual musings and philosophical deliberations. Indeed, the tourist has been portrayed in primarily derisive ways. Nietzsche’s remark, “Tourists—they climb mountains like animals, stupid and perspiring, no one has told them that there are beautiful views on the way,” epitomizes the dominant attitude. Why does the figure of the tourist elicit such negative reactions? Do the sentiments perhaps imply something else, or is the tourist a doppelgänger, not anomalous or marginal but normative—a paradigmatic figure? If so, then what can be said of the poetics and politics of the tourist conceptualized as a paradigmatic subject?
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The purpose of this chapter is to propose a theory which may lead to a holistic description of the mechanism of touristic phenomena. In so doing, the central discussion is to…
Abstract
The purpose of this chapter is to propose a theory which may lead to a holistic description of the mechanism of touristic phenomena. In so doing, the central discussion is to provide descriptive answers to basic questions. It will not be a sociological or anthropological discourse. Instead, it will use perspectives from environmental psychology, genetics, and a theory of information energy in elementary particle physics. The study of tourism, though it is not a distinct disciplinary field, must provide a grand theory. In this chapter, the discussions mainly focus on the concept of tourist to provide several ideas to amend its definition, which may directly correspond to an overall view of touristic phenomena.