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ABSTRACT

Wei Huang^1,*, Zhi Zhou²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 68-68, 2019, DOI:10.32604/icces.2019.05066
Abstract Structural members of different materials in hybrid structures have different damage performances. Based on the classical Park-Ang damage model, a consistent modification of that model is proposed for structural members of different materials in order to determine the behavior and the damage process from member-level to structure-level. Furthermore, the specific limit values of this damage model at various performance levels are calculated. Obvious differences have been found between the limit values of different types of members. In order to unify the damage limits that correspond to predefined performance levels such that a comparison between different members can be made directly,… More >

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643

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Vaughan R. Voller
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 69-69, 2019, DOI:10.32604/icces.2019.05082
Abstract There has been current interest in studying diffusion processes that involve memory and non-locality. These phenomena can be modeled using fractional calculus tools. A fractional derivative in time, a convolution of previous states of the system, modeling memory and a fractional derivative in space, a convolution over aspace domain, modeling non-locality. In this work we consider how such treatments can be incorporated into models of phase change systems. In particular, we examine the consequences of replacing the time and space derivative in the classic one-phase Stefan melting problem with appropriate fractional derivatives. A number of alternative formations and associated computational… More >

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1006

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685

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ABSTRACT

Igor Vušanović^1,*, Vaughan R Voller²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 70-70, 2019, DOI:10.32604/icces.2019.05185
Abstract In the modeling of liquid to solid phase change processes the movement of the solid phase (e.g., the grains that form when solidifying an alloy) can have a significant impact on the timing and pattern of the process. While a number of solidification models account for the movement of the solid phase, additional analysis is needed to fully understand the phenomena and guide in the selection of appropriate numerical technologies for its resolution. Towards this end, here, we introduce a reduced complexity model (RCM) to describe the solidification of an initially liquid binary material flowing between two parallel cooled plates… More >

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684

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Shigeru Obayashi^*, Aiko Yakeno
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 71-71, 2019, DOI:10.32604/icces.2019.05229
Abstract In our laboratory, we have been conducting research focusing on a data-driven approach to fluid engineering for design. Designing aerospace machines, these days requires more advanced factors. The recent development of supercomputer leads that we must treat more complex flow phenomena that brings uncertainty, with the more advanced design considered. Such as a reduced-order model and a data assimilation method, to estimate and reduce the uncertainty in numerical simulations, are potential ways to assist the advanced design. That is by use of experimental or observational data and numerical analysis of physical equations. Recently, we are focusing on observation sensitivity, in… More >

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746

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Zhigang Zhu^1,*, Wenxiang Xu¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 72-72, 2019, DOI:10.32604/icces.2019.04957
Abstract The volume fraction of interphase is an important microstructure parameter in the prediction of macroscopic properties of particulate composites. Currently, some researchers have presented theoretical and numerical investigations on the interphase fraction for spherical particle systems, and even quantify the influence of interphase fraction on the overall elastic and transport properties of particulate composites. However, the overlapping interphase fraction in polydisperse non-spherical particle systems is still an open issue. In this study, a generic theoretical model is formulated to derive the overlapping interphase fraction for polydisperse 2D non-circular and 3D non-spherical particle systems by means of the statistical geometry of… More >

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958

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689

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Taku Nonomura
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 73-74, 2019, DOI:10.32604/icces.2019.05266
Abstract In this presentation, a family of Kalman filter dynamic mode decomposition, which consists of algorithms of the linear Kalman filter DMD method which identify the linear system and the extended Kalman filter DMD method which simultaneously identify the system and estimates state variable, is introduced. Then, the application of the extended Kalman filter DMD to data assimilation is discussed. More >

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868

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Junbo Wang^*, Leiting Dong
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 75-75, 2019, DOI:10.32604/icces.2019.04820
Abstract In this study, two/three-dimensional computational grains are developed for micromechanical modeling of heterogeneous materials with nanoscale inhomogeneities, considering the interface stress effect. Two types of computational grains are developed, depending on the types of inhomogeneity in each element. Each computational grain can include alternatively a spherical void or a spherical elastic inclusion. In these computational grains, an inter-element compatible displacement field is assumed along the element outer-boundary, and interior displacement fields in the matrix as well as in the inclusion are independently assumed as T-Trefftz trial functions. For planar problems, complex potentials are used to derive the Trefftz trial displacement… More >

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928

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807

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Tian Yang¹, Leiting Dong^1,*, Satya N. Atluri²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 76-76, 2019, DOI:10.32604/icces.2019.05078
Abstract In this paper, a new method, named the Fragile Points Method (FPM), is developed for computer modeling in engineering and sciences. In the FPM, simple, local, polynomial, discontinuous and Point-based trial and test functions are proposed based on randomly scattered points in the problem domain. The local discontinuous polynomial trial and test functions are postulated by using the Generalized Finite Difference method. These functions are only piece-wise continuous over the global domain. By implementing the Point-based trial and test functions into the Galerkin weak form, we define the concept of Point Stiffnesses as the contribution of each Point in the… More >

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783

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1

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ABSTRACT

Xianglong Su^*, Wenxiang Xu, Wen Chen
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 77-77, 2019, DOI:10.32604/icces.2019.05090
Abstract Creep of concrete can last for decades, which displays the ultra-slow rheological phenomena. As an empirical formula, the logarithmic law is usually used to describe the ultra-slow creep. However, the logarithmic law does not always work well especially for the long-term creep. And its corresponding relaxation response cannot be obtained analytically. It is known that the Mittag-Leffler and the inverse Mittag-Leffler functions are generalized from the exponential and the logarithmic functions, respectively. And the inverse Mittag-Leffler function is much slower and generalized than the logarithmic function. In this paper, we use the non-local structural derivative to establish a new Maxwell-type… More >

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1079

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683

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Jintao He, Dong Lei^*, Xuwei Cui, Pengxiang Bai, Feipeng Zhu
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 78-78, 2019, DOI:10.32604/icces.2019.05228
Abstract With the combination of scanning electron microscope (SEM) and digital image correlation (DIC), the mechanical properties of interfacial transition zone (ITZ) in concrete are experimentally studied. The experimental compression tests are performed on cuboid samples whose half part is aggregate and the other part is mortar. The morphology of the ITZ is captured by SEM under compressive load, and from the recorded images the deformation of the ITZ is analyzed. After that, the distribution of the nominal compressive elastic modulus of the ITZ is obtained along the distance from the aggregate to the mortar, which can be used to characterize… More >

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1100

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795

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Jichang Wang, Xiaoming Guo^*, Xiaoxiao Sun
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 79-79, 2019, DOI:10.32604/icces.2019.05248
Abstract Cement mortar is an important component of many composite materials and one of the most widely used materials in engineering construction. At microscopic level, cement mortar can be regarded as a multiphase material composed of fine aggregates, cement paste, and a great many of initial defects, the form of which are micro-cracks and micro-voids. The macroscopic properties of cement mortar will be influenced by mechanical properties of different constituents and complex internal structures. The microscopic model containing micro-voids is established by the method of secondary development. The process of cement mortar damage fracture is studied. The fracture toughness of fine… More >

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693

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Wei Cai^*, Hua Chen
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 80-80, 2019, DOI:10.32604/icces.2019.05672
Abstract Recent decades have witnessed a fast growing research on the theory of wave propagation in granular materials because of its important applications of frequency dependent attenuation. Fractional calculus has been recognized as an efficient tool to model such kind of phenomena. This study firstly presented a survey of the frequency-dependent attenuated fractional wave models. To have a better understanding of the wave propagation in layered materials, the variable-order fractional wave equation is subsequently proposed on the basis of the corresponding viscoelastic constitutive equation. Numerical simulations compared with traditional models are presented by the implicit finite difference method to the efficiency… More >

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766

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Lin Jiang^1,*, Na Wei^1,*, Jinzhou Zhao¹, Shouwei Zhou^1,2, Liehui Zhang¹, Qingping Li³, Guorong Wang¹, Jun Zhao¹, Kaisong Wu¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 81-83, 2019, DOI:10.32604/icces.2019.04515
Abstract With huge reserves, marine natural gas hydrate is one of the most potential unconventional alternative energy sources after shale gas, coalbed methane and tight gas. The research and pilot engineering of natural gas hydrate exploitation technology mainly adopts the depressurization method at home and abroad, all of which refer to the exploitation technology of conventional oil and gas.
While using the depressurization method to exploit the non-diagenetic gas hydrate, the undersea hydrate decomposes in situ, partly flows to the bottom of the well, and escapes into the seawater in large quantities, and the hydrate will face the following six risks… More >

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Na Wei^1,*, Jinzhou Zhao¹, Wantong Sun¹, Shouwei Zhou¹, Liehui Zhang¹, Qingping Li², Haitao Li¹, Qiang Fu^1,2, Xin Lv², Lijun Zheng²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 84-86, 2019, DOI:10.32604/icces.2019.04533
Abstract Currently, marine natural gas hydrate has attracted people’s attention due to its huge amount of resources. As a creative way to securely and efficiently exploit metastable hydrate reservoir which is in shallow subsurface of sea floor and with weak cementing, the method of solid fluidization exploitation is to excavate and crush the marine natural gas hydrate reservoir, transport the hydrate to the sea surface platform through the airtight pipeline, and finally the methane gas is obtained after post-processing.
In the process that the hydrate solid particles are transported up, as the temperature rises and the pressure drops, the hydrate rises… More >

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761

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Hongwei Yang^1,*, Jun Li¹, Gonghui Liu^1,2
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 87-87, 2019, DOI:10.32604/icces.2019.05080
Abstract When gas kick occurs in deepwater drilling, solid hydrate particles are easily formed during the gas bubble rising in the wellbore under low temperature and high pressure conditions, which not only affects the flow characteristics of the mud, but also may lead to wellbore blockage and increase the difficulty and risk of well control treatment.
In this paper, based on water-in-oil drilling fluid, a comprehensive model of hydrate shell growing on droplet surface is established, including an inward growth model and an outward growth model of hydrate shell. The main factors considered in this model are: (i) mass transfer rate… More >

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934

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640

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Ye Chen, Yonghai Gao, Guizhen Xin, Wang Yao, Dongzhi Gao, Litao Chen, Baojiang Sun^*
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 88-89, 2019, DOI:10.32604/icces.2019.05522
Abstract Natural gas hydrate is regarded as a kind of potential alternative energy resource and attracts the attention all over the world. Geological surveys have found that most natural gas hydrates are buried at the bottom of the sea. Several development methods, such as depressurization, thermal stimulation and inhibitor injection are proposed gradually on the basis of hydrate special properties, obtaining certain trial-produce performance. It is of great significance to learn the flow rules underground for production safety guarantee and efficiency improvement. However, the special phase transition of hydrate between solid and fluid accompanied by energy and mass change makes it… More >

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734

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Hideo Matsufuru^1,*, Kohsuke Sumiyoshi²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 90-90, 2019, DOI:10.32604/icces.2019.05390
Abstract The core collapse supernovae are one of key phenomena to understand the history of the Universe and the origin of heavy elements. To understand their explosion mechanism, large scale numerical simulations are essential that require to solve a multi-physics system described by coupled equations of hydrodynamics and neutrino-radiation transfer in multidimensions. Since the neutrino transfer is governed by the Boltzmann equation in six-dimensional space, necessary computational resource rapidly increases as the number of grids in simulations grows. So far numerical studies have been performed mostly on massively parallel computers and only a few studies have been made using accelerator architectures,… More >

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740

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Bingyu Ni, Chao Jiang^*
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 91-91, 2019, DOI:10.32604/icces.2019.05517
Abstract Uncertain parameters with inherent spatial variability are commonly encountered in engineering. These include material properties of the heterogeneous media such as concrete or porous rock, external loads such as wind or snow loads applied on structures, etc. This type of uncertain parameters is traditionally quantified by the random field model, while the large amount of information required in construction of the precise probability distribution functions is often difficult to obtain for many practical engineering problems. The authors propose an interval field model to represent the spatial uncertainties with insufficient information, in which the variation of the parameter at any location… More >

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775

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Guiping Liu^*, Sheng Liu
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 92-92, 2019, DOI:10.32604/icces.2019.05523
Abstract In engineering multi-objective optimization of structures, the parameters involved in the problems are usually given deterministic values. However, due to the presence of manufacturing and measurement errors, uncertainty inevitably exists in the geometrical properties of the structure, the material properties, the boundary conditions, etc. For uncertain problems, the interval optimization methods are widely used. They describe the uncertainty by intervals which only need to find the upper and lower bounds of the uncertain parameters instead of constructing the exact probability distribution function. However, in multi-objective optimization problems, if considered all the upper and lower bounds of the objective functions as… More >

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691

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Seung Kyo Lee, Dongil Chu, Eun Kyu Kim^*
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 93-93, 2019, DOI:10.32604/icces.2019.04995
Abstract We studied on a liquid exfoliation technique for the robust production of transition metal dichalcogenides (TMDC) thin films, because this technique has advantages for residue-free, large-scale, and low-cost fabrication. During the process of liquid exfoliation, a mixture of DI water and ethanol was used to obtain higher concentrations of TMDC flakes in the solution compared to that in water-based solution. The film thicknesses were controlled by a two-step centrifuge process to analyze the influence on the photovoltaic properties with gold/TMDC/silicon geometry. Based on ultraviolet photoelectron spectroscopy measurement results, the energy band diagram of the devices using MoS₂ and WS₂ films… More >

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774