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ABSTRACT

Renyong Zhang
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 22-24, 2019, DOI:10.32604/icces.2019.04656
Abstract This article aims to give a method for the fast numerical computation and continuation of families of periodic orbits in the strong nonlinear circular restricted three-body problem, and we focus our attention on those in the Earth-moon system. This work is primarily motivated by a series of missions and plans that take advantages of the three-body periodic orbits associated with the collinear equilibrium points, L1, L2 and L3 or two gravitational celestial bodies. We describe the method used that allows to follow individual families of periodic orbits by numerical continuation, which based on Jacobi energy surface, of More >

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Xin Wang^1,*, Xiaokui Yue¹, Honghua Dai¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 25-25, 2019, DOI:10.32604/icces.2019.04851
Abstract With the rapid development of space technologies, the requirements of precise pointing and extreme stability increase a lot for spacecrafts. For some spacecrafts, sensitive payloads, including space telescopes, imaging sensors, space-borne optical interferometers are essential for the missions, which require a relatively quiet working environment. Generally, a spacecraft includes multiple instruments, including reaction wheels, cryogenic coolers, control moment gyroscopes and solar array drives, which can produce micro-vibrations. However, the micro-vibrations from the spacecraft and orbital perturbations both have a serious influence on the performance of sensitive payloads. For the sensitive payloads, performance requirements of low… More >

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1013

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Bin Dong^1,2,3, Changyong Jiang^1,3,*, Xiang Liu^1,3, Lixi Huang^1,3
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 26-26, 2019, DOI:10.32604/icces.2019.05017
Abstract How to reduce fan noise has always been a significant research topic in equipment ranging from small-scale devices, such as computer cooling fans and building ventilation fans, to large high bypass ratio turbo engines. In recent years, in order to produce higher pressure rise or larger flow rate with lower noise level in the fan stage, interest in the contra-rotating fan (CRF) configuration has been rekindled. The Vold-Kalman order tracking filter technique was employed to separate tonal and broadband noise components from CRF acoustic data to study the characteristics of the noise spectrum. Based on More >

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945

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Wei Xia^1,2,*, Kun Wang¹, Haitao Yang¹, Shengping Shen¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 27-27, 2019, DOI:10.32604/icces.2019.05197
Abstract Panel flutter arises from the aeroelastic instability of the skin structures on the high-speed vehicles, usually in supersonic regime and combined with thermal environment. Unlike the catastrophic flutter of the wings, panel flutter tends to be treated as non-catastrophic one. The nonlinear panel flutter response is of great interest to find the fatigue loading spectra. Present work introduces an aeroelastic model for a thermal isolating panel made from functionally graded materials (FGMs). The Mindlin plate theory is employed to establish the structural equations, the first-order piston theory is adopted for the supersonic aerodynamic loads, and… More >

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930

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Ryota Misawa^*,1, Sunghoon Lim¹, Shinichi Maruyama¹, Takayuki Yamada¹, Kazuhiro Izui¹, Shinji Nishiwaki¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 28-28, 2019, DOI:10.32604/icces.2019.05203
Abstract Multi-material design, where more than one material is placed in appropriate configurations, is indispensable to reduce weights of mechanical components while keeping their required performances. Multi-material topology optimization is a promising method for realizing such efficient multi-material designs.
The present authors’ group has been developing a multi-material topology optimization method using level set functions and reaction diffusion equations. In this method, multiple level set functions are used to represent the geometrical structure (i.e., shape and topology) and distribution of materials according to the MM-LS (Multi-Material Level Set) model. Then, each level set function is updated using… More >

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859

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Zixin Zhang^1,2,*, Shuaifeng Wang^1,2, Xin Huang^1,2
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 29-29, 2019, DOI:10.32604/icces.2019.04704
Abstract Block theory is widely used in numerical simulation of rock engineering due to its concision and fast-calculation. The paper proposes block theory for TBM (tunnel boring machine) tunnels to extend the traditional block theory applicative for tunnels excavated by TBM. In the proposed method, TBM-block interaction forces are taken into consideration. Subsequently, an index is proposed to estimate the stability of the TBM tunnel based on safety factor at every given chainage of the tunnel. Finally, a real water-conveyance tunnel project is studied with block theory for TBM tunnels. The simulation results include the joint More >

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943

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Longgang Tian^1,2,*, Xiao Wang^1,2, Qi Zhang^1,2
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 30-30, 2019, DOI:10.32604/icces.2019.04809
Abstract Various defects such as cracks and holes exist in coal-rock body and they have a large influence on the mechanical properties of coal-rock. Therefore, it is of great significance to study the fracture characteristics in order to understand the instability mechanism of coal body. In this study, a variety of defective coal-rock specimens with different cracks and holes were established by PFC software, and then the characteristics of stress-strain and crack evolution law of coal-rock were studied. Results show that the mechanical properties, crack propagating characteristics, propagation forms of initial crack and final crack distributions More >

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895

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Lu Wang, Guangyan Liu, Yanan Yi, Shaopeng Ma^*
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 31-31, 2019, DOI:10.32604/icces.2019.04974
Abstract Nuclear graphite is a key material in high temperature gas-cooled reactors. The evaluation of its damage evolution is of great importance for safety assessment of nuclear graphite structures. However, the damage properties of nuclear graphite are difficult to characterize by the traditional testing approaches, i.e., uniaxial tension and compression tests due to the inconvenience of conducting uniaxial tension/compression tests. In this paper, an inverse method was developed to identify the damage parameters of a nuclear graphite material IG11. The method is based on the non-contact digital image correlation and finite element model updating techniques, and More >

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890

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Yao Tang^*, Dongyang Feng, Yudan Gou, Yongchang Cai
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 32-32, 2019, DOI:10.32604/icces.2019.05015
Abstract It is a serious challenge to estimate the safety and ultimate bearing capacity of a corroded large-span drainage culvert. In this paper, a simplified computational model based on matrix displacement method is established. Within the framework of concrete structure principles and structural mechanics, both the ultimate strength and flexural stiffness reduction of key sections are considered in this model. This simplified model can greatly reduce the computational cost and is readily applicable to engineering practice. Its validity and availability have been verified by finite element analysis with a damage-plasticity coupled concrete constitutive model and physical More >

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925

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Wei Wu^1,2,3, Yaji Jiao^2,*, Hehua Zhu^1,2,3, Rui Jin²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 33-33, 2019, DOI:10.32604/icces.2019.05324
Abstract When shield tunnels pass through gas-bearing strata, leakage may happen through the gasketed segmental joints, which puts threats on the safety during construction and operation process. Previous studies on sealing performance of the gasketed joints have focused on the waterproof behavior. However, differences in physical characteristics between liquid and gas, lead to different permeation properties. This paper presents a combined experimental and computational study to investigate the gas sealing behavior of the gasketed joints used for a shield tunnel project, i.e., Sutong GIL Utility Tunnel, which passes through soft soil strata rich in high-pressure biogas… More >

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926

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Chengbin Du^*, Peng Zhang
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 34-34, 2019, DOI:10.32604/icces.2019.05397
Abstract Considering the existence of side-face loads, a new scaled boundary finite element (SBFEM) shape function is used to study the problem of wing crack propagation. In the solution of crack contact, the contact interface constraint is introduced by Lagrange multiplier method. The polygon SBFEM remeshing technology is used to simulate the crack propagation problem with single and multiple wing crack. Compared with related experimental and numerical simulation results, the correctness and effectiveness of the new SBFEM shape function in solving the wing crack propagation are verified. It is found that under pressure, the wing crack More >

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1191

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869

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ABSTRACT

Yabin Yang, Guangyu Shi^*
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 35-35, 2019, DOI:10.32604/icces.2019.05623
Abstract The efficient and high performance orthotropic steel decks have been widely used in long span bridges over the world. The initial defects at welded joints of orthotropic steel bridge decks will undergo fatigue failure under the action of live load of moving vehicles on the bridge decks. And the fatigue cracks at the rib-to-deck welded joints are the most dangerous cracks for the orthotropic steel bridge decks. Therefore, the fatigue life evaluation of the rib-to-deck welded joints is very important for the safety of orthotropic steel bridge decks. This paper presents a crack propagation-based model… More >

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1062

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Tomoyuki Enomoto, Kazuhiko Kakuda, Shinichiro Miura
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 36-39, 2019, DOI:10.32604/icces.2019.05292
Abstract In this paper, the nonlinear activation functions based on fluid dynamics are presented. We propose two types of activation functions by applying the so-called parametric softsign to the negative region. We apply the activation function to CNN (Convolutional Neural Network) which performs image recognition and approaches from multiple benchmark datasets such as MNIST, CIFAR-10. Numerical results demonstrate the workability and the validity of the present approach through comparison with other numerical performances. More >

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1030

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ABSTRACT

Renata Gnatowska
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 40-40, 2019, DOI:10.32604/icces.2019.05110
Abstract The wind pressure loads are affected by a wide range of features involving wind flow conditions, size and shape of the buildings and their neighborhoods. Most of the available publications present the wind load characteristics of buildings with neighbouring structures as a form of idealised urban street canyons, isolated building and much less frequently as group of buildings or part of the urban terrain. The aim of such analyses is to gain a better understanding of the physics of isolated phenomena which, under the influence of other interactions, e.g., additional buildings, strongly change. This study… More >

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817

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Witold Elsner^1,*, Artur Dróżdż¹, Paweł Niegodajew¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 41-41, 2019, DOI:10.32604/icces.2019.05114
Abstract Estimation of the wall skin friction in a turbulent boundary layer (TBL) is always challenging due to the large gradient of mean velocity in the near-wall region and requires precise measurements of mean velocity in viscous sublayer. This problem becomes even more serious for a flow with a strong positive pressure gradient where the low velocity closes the wall occurs. Hence, choosing an appropriate measuring technique for the wall skin friction measurement is an important issue. Most commonly used for this purpose is hot-wire technique, where determination of mean velocity gradient is strongly dependent on… More >

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980

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A. Takahashi¹, K. Motoyama², K. Misaji^1,*
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 42-42, 2019, DOI:10.32604/icces.2019.05446
Abstract Seismic isolation laminated rubber is used as an effective means for suppressing damage to buildings and people in buildings by earthquakes. The restoring-force characteristic of the rubber has non-linerar-vibration characteristics which depend on the displacement amplitude. PFT-ELS (Equivalent linear system using the restoring force model of power function type) has been applied for calculating approximate responses of various non-linear-vibration systems [Kazuhito, M., et al. (1994); Koichi, S., et al. (1995); Koichi, S., et al. (1996)]. The authors have also applied to optimize the non-linear vibration characteristics of the isolation rubber using PFT-ELS and GA [Ayumi,… More >

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ABSTRACT

Akira Matsumoto^1,*, Taku Itoh², Soichiro Ikuno¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 43-43, 2019, DOI:10.32604/icces.2019.05496
Abstract In this study, an improvement technique of convergence property of Communication Avoiding (CA) Kyrlov subspace method is proposed, and parallelization efficiencies of CA Krylov subspace method is numerically investigated. As is known that most of all the procedures of the Krylov subspace method are constituted by addition of vectors, inner products and multiplication of matrices and vectors. These operations are very easy to derive a parallelization efficiency. However, the candidate coefficient matrices of linear system obtained from the numerical analysis such as Finite Element Method are large sparse matrices, and communications occur between Processing Units… More >

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815

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ABSTRACT

Taku Itoh^1,*, Soichiro Ikuno²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 44-44, 2019, DOI:10.32604/icces.2019.05521
Abstract The purpose of this study is to efficiently solve N by N linear systems Ax = b obtained by eXtended Element-free Galerkin method (X-EFG). X-EFG is one of the meshless methods for discretizing partial differential equations, and the linear systems have asymmetric saddle point structure. In this study, the block Krylov subspace methods have been applied for solving linear systems obtained by X-EFG. Note that the block Krylov subspace methods are usually employed for solving linear systems with multiple right hand sides, AX = B, where X = [x₁, x₂, …, x_L], B = [b₁, b₂, …, b_L], and L is… More >

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864

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Jeffrey T. Fong^1,*, Pedro V. Marcal², Robert Rainsberger³, N. A. Heckert¹, J. J. Filliben¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 45-45, 2019, DOI:10.32604/icces.2019.05432
Abstract When a small crack is detected in a pressure vessel or piping, we can estimate the fatigue life of the vessel or piping by applying the classical law of fracture mechanics for crack growth if we are certain that the crack growth exponent is correct and the crack geometry is a simple plane. Unfortunately, for an ageing vessel or piping, the degradation will change the crack growth exponent, and the crack will advance not in a simple planar fashion. To validate the crack growth exponent for an ageing vessel or piping with a crack of… More >

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996

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V. Sladek^*, M. Repka, J.Sladek
The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 46-46, 2019, DOI:10.32604/icces.2019.05773
Abstract A novel discretization method is proposed and developed for numerical solution of boundary value problems governed by partial differential equations. In contrast to the standard Finite Element Method (FEM), the analyzed domain is not covered by a mesh of fixed non-overlapping finite elements, but only a net of nodes is used for discretization. Around each node, there is properly created a Lagrange finite element and the spatial variation of field variables is interpolated within this element in terms of nodal values and polynomial shape functions defined in the intrinsic coordinate space of the finite element.… More >

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879