• Title/Summary/Keyword: homogeneous deformation

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Effect of nonlocal parameter on nonlocal thermoelastic solid due to inclined load

  • Lata, Parveen;Singh, Sukhveer
    • Steel and Composite Structures
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    • v.33 no.1
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    • pp.123-131
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    • 2019
  • The present investigation is concerned with two dimensional deformation in a homogeneous nonlocal thermoelastic solid with two temperature. The nonlocal thermoelastic solid is subjected to inclined load. Laplace and Fourier transforms are used to solve the problem. The bounding surface is subjected to concentrated and distributed sources. The analytical expressions of displacement, stress components, temperature change are obtained in the transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerical simulated results are depicted graphically to show the effect of angle of inclination and nonlocal parameter on the components of displacements, stresses and conductive temperature. Some special cases are also deduced from the present investigation.

Thermomechanical interactions in transversely isotropic thick circular plate with axisymmetric heat supply

  • Lata, Parveen;Kaur, Iqbal
    • Structural Engineering and Mechanics
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    • v.69 no.6
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    • pp.607-614
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    • 2019
  • The present investigation has focus on the study of deformation due to thermomechanical sources in a thick circular plate. The thick circular plate is homogeneous, transversely isotropic with two temperatures and without energy dissipation. The upper and lower surfaces of the thick circular plate are traction free. The Laplace and Hankel transform has been used for finding the general solution to the field equations. The analytical expressions of stresses, conductive temperature and displacement components are computed in the transformed domain. However, the resulting quantities are obtained in the physical domain by using numerical inversion technique. Numerically simulated results are illustrated graphically. The effects of two temperatures by considering different values of temperature parameters are shown on the various components. Some particular cases are also figured out from the present investigation.

Performance of novel dynamic installed anchors during installation and monotonic pullout

  • Kim, Youngho;Rosher, Lachlan Thomas
    • Geomechanics and Engineering
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    • v.18 no.2
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    • pp.153-159
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    • 2019
  • This paper examines the results from three-dimensional dynamic finite element analysis undertaken to develop a new dynamically installed anchor (DIA). Several candidate shapes of new DIAs were selected after an investigation into previous researches of existing DIA designs. The performances of selected DIAs during the installation and loading in non-homogeneous clay were investigated through large deformation finite element (LDFE) analyses. Findings were compared to the current anchors in operation (i.e., Torpedo and Omni-Max DIA) to assess the viability of the new designs in the field. Overall, the anchor embedment depths of the novel DIAs lied under the results of OMNI-Max DIA. And also, the tracked anchor trajectory confirmed that, the novel DIAs dove deeper with stiffer travelling angle, compared to the OMNI-Max DIA. These elements are more critical and beneficial especially in a field where the achieved embedment depths are generally low.

Free Volume Formation in Amorphous Alloys: a Molecular Dynamics Study (비정질 합금의 자유부피 생성기구: 분자동력학적 고찰)

  • Lee, Chang-Myeon;Park, Kyoung-Won;Lee, Byeong-Joo;Shim, Jae-Hyeok;Lee, Jae-Hoon;Lee, Jae-Chul
    • Korean Journal of Metals and Materials
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    • v.46 no.11
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    • pp.701-707
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    • 2008
  • This study examined the creation mechanism of free volume during homogeneous deformation induced by the elastostatic compression at room temperature. Experiments demonstrated that amorphous alloys subjected to the elastostatic compression underwent structural disordering, during which densely packed polyhedra breakdown to form new, loosely packed ones, resulting in the creation of excess free volume. A combination of experiments and molecular dynamics simulations are used to explore fundamental issues on how free volume is created during elastostatic compression.

Effect of rotation and inclined load in a nonlocal magneto-thermoelastic solid with two temperature

  • Lata, Parveen;Singh, Sukhveer
    • Advances in materials Research
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    • v.11 no.1
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    • pp.23-39
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    • 2022
  • This work deals with the two-dimensional deformation in a homogeneous isotropic nonlocal magneto-thermoelastic solid with two temperatures under the effects of inclined load at different inclinations. The mathematical model has been formulated by subjecting the bounding surface to a concentrated load. The Laplace and Fourier transform techniques have been used for obtaining the solution to the problem in transformed domain. The expressions for nonlocal thermal stresses, displacements and temperature are obtained in the physical domain using a numerical inversion technique. The effects of nonlocal parameter, rotation and inclined load in the physical domain are depicted and illustrated graphically. The results obtained in this paper can be useful for the people who are working in the field of nonlocal thermoelasticity, nonlocal material science, physicists and new material designers. It is found that there is a significant difference due to presence and absence of nonlocal parameter.

Effect of porosity distribution on free vibration of functionally graded sandwich plate using the P-version of the finite element method

  • Hakim Bentrar;Sidi Mohammed Chorfi;Sid Ahmed Belalia;Abdelouahed Tounsi;Mofareh Hassan Ghazwani;Ali Alnujaie
    • Structural Engineering and Mechanics
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    • v.88 no.6
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    • pp.551-567
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    • 2023
  • In this work, the free vibration analysis of functionally graded material (FGM) sandwich plates with porosity is conducted using the p-version of the finite element method (FEM), which is based on the first-order shear deformation theory (FSDT). The sandwich plate consists of two face-sheet layers of FGM and a homogeneous core layer. The obtained results are validated using convergence and comparison studies with previously published results. Five porosities distribution models of FGM sandwich plates are assumed and analyzed. The effect of the thickness ratio, boundary conditions, volume fraction exponents, and porosity coefficients of the top and bottom layers of FGM sandwich plates on the natural frequency are addressed.

Deflections, stresses and free vibration studies of FG-CNT reinforced sandwich plates resting on Pasternak elastic foundation

  • Bendenia, Noureddine;Zidour, Mohamed;Bousahla, Abdelmoumen Anis;Bourada, Fouad;Tounsi, Abdeldjebbar;Benrahou, Kouider Halim;Bedia, E.A. Adda;Mahmoud, S.R.;Tounsi, Abdelouahed
    • Computers and Concrete
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    • v.26 no.3
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    • pp.213-226
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    • 2020
  • The present study covenants with the static and free vibration behavior of nanocomposite sandwich plates reinforced by carbon nanotubes resting on Pasternak elastic foundation. Uniformly distributed (UD-CNT) and functionally graded (FG-CNT) distributions of aligned carbon nanotube are considered for two types of sandwich plates such as, the face sheet reinforced and homogeneous core and the homogeneous face sheet and reinforced core. Based on the first shear deformation theory (FSDT), the Hamilton's principle is employed to derive the mathematical models. The obtained solutions are numerically validated by comparison with some available cases in the literature. The elastic foundation model is assumed as one parameter Winkler - Pasternak foundation. A parametric study is conducted to study the effects of aspect ratios, foundation parameters, carbon nanotube volume fraction, types of reinforcement, core-to-face sheet thickness ratio and types of loads acting on the bending and free vibration analyses. It is explicitly shown that the (FG-CNT) face sheet reinforced sandwich plate has a high resistance against deflections compared to other types of reinforcement. It is also revealed that the reduction in the dimensionless natural frequency is most pronounced in core reinforced sandwich plate.

An Experimental Study on the Behaviour of Tunnel Excavated in a Homogeneous Ground by Two-Stage Excavation (균질지반에서 2단계로 굴착되는 터널의 거동특성에 대한 실험적 연구)

  • 김동갑;박승준;이상덕
    • Tunnel and Underground Space
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    • v.14 no.5
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    • pp.345-352
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    • 2004
  • In a shotcrete support system, the cooperation of the ground and the shotcrete lining makes it possible to transfer the shear stress to the shotcrete lining, which is dedicated to form a stable structure. In this study, a homogeneous model ground with constant strength was produced by using gypsum and the tunnel was excavated with a top heading method under the definite initial stress. During the excavation, the stress in the ground around the tunnel and the deformation of shotcrete lining were measured, The tensile stress was generated in tangential direction in the ground near the tunnel and in the shotcrete lining due to tunnel excavation. This shows the unified behavior of the ground and shotcrete lining, which is the most typical characteristic of the shotcrete support. As a result, the rates of in-situ stress during the excavation at a top boundary line was 9% and at top arch heading 15%. It was 48% right after excavating the heading and 94% before cutting the bench.

A Study on Microstructural Evolution of Hot Rolled AZ31 Magnesium Alloy Sheets (열간 압연한 AZ31 마그네슘합금 판재의 미세조직 발달에 관한 연구)

  • Kim S. H.;Yim C. D.;You B. S.;Seo Y. M.;Chung I. S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.08a
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    • pp.63-71
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    • 2004
  • Recently, a sheet forming process of Mg alloys is highlighted again due to increasing demand for Mg wrought alloys in the applications of casings of mobile electronics and outer-skins of light-weight transportation. Microstructure control is essential for the enhancement of workability and formability of Mg alloy sheets. In this research, AZ31 Mg alloy sheets were prepared by hot rolling process and the rolling condition dependency of the microstructure and texture evolution was studied by employing a conventional rolling mill as well as an asymmetric rolling mill. When rolled through multiple passes with a small reduction per pass, fine-grained and homogeneous microstructure evolved by repetitive dynamic and static recrystallization. With higher rolling temperature, dynamic recrystallization was initiated in lower reduction. However with increasing reduction per pass, deformation was locallized in band-like regions, which provided favorable nucleation sites f3r dynamic recrystallization. Through post annealing process, the microstructures could be transformed to more equiaxed and homogeneous grain structures. Textures of the rolled sheets were characterized by $\{0002\}$ basal plane textures and retained even after post annealing. On the other hand, asymmetrically rolled and subsequently annealed sheets exhibited unique annealing texture, where $\{0002\}$ orientation was rotated to some extent to the rolling direction and its intensity was reduced.

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A Study on the Estimation of Homogeneous Physical Properties of Molten Carbonate Fuel Cell Stacks (용융탄산염형 연료전지 스택의 균질 물성치 추정에 관한 연구)

  • Lee, Sang-Wook;Suh, Yong-S.
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.7
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    • pp.2939-2944
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    • 2011
  • The performance and efficiency of a Molten Carbonate Fuel Cell system will improve with the aids of numerical simulations such as finite element analysis. For best simulation results, the virtual model must accurately reflect the actual model including the material properties. It is very difficult, however, to make a detailed numerical model of the stack that consists of hundreds of layers of unit cells composed of various materials like metal, ceramics, polymer, etc. Instead, a practical approach is to find a homogenized material property of the stack as a whole as an approximate replacement. In this paper, the compression ratio of a unit cell is introduced, and a new method is proposed to estimate the homogeneous material properties for both the active and the manifold regions of the stack under the assumption that the compressive deformation occurs only at the separators and matrices in the unit cells. The estimated properties are applied successfully to simulating an actual stack.