• Title/Summary/Keyword: Lay theory

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Thermomechanical buckling of rectangular, shear-deformable, composite laminated plates

  • Ge, Y.S.;Yuan, W.X.;Dawe, D.J.
    • Structural Engineering and Mechanics
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    • v.13 no.4
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    • pp.411-428
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    • 2002
  • The B-spline finite strip method is developed for the prediction of the buckling of rectangular composite laminated plates under the combined action of applied uniaxial mechanical stress and increasing temperature. The analysis is conducted in two stages, namely an in-plane stress analysis in the pre-buckling stage to determine the pre-buckling stresses, followed by a buckling analysis using these determined stresses. The buckling analysis is based on the use of first-order shear deformation plate theory. The permitted lay-up of the laminates is quite general, within the constraint that the plate remains flat prior to buckling, and a wide range of boundary conditions can be accommodated. A number of applications is described and comparison of the results generated using the finite strip method is made with the results of previous studies.

Free vibration analysis of composite cylindrical shells with non-uniform thickness walls

  • Javed, Saira;Viswanathan, K.K.;Aziz, Z.A.
    • Steel and Composite Structures
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    • v.20 no.5
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    • pp.1087-1102
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    • 2016
  • The paper proposes to characterize the free vibration behaviour of non-uniform cylindrical shells using spline approximation under first order shear deformation theory. The system of coupled differential equations in terms of displacement and rotational functions are obtained. These functions are approximated by cubic splines. A generalized eigenvalue problem is obtained and solved numerically for an eigenfrequency parameter and an associated eigenvector which are spline coefficients. Four and two layered cylindrical shells consisting of two different lamination materials and plies comprising of same as well as different materials under two different boundary conditions are analyzed. The effect of length parameter, circumferential node number, material properties, ply orientation, number of lay ups, and coefficients of thickness variations on the frequency parameter is investigated.

Structural Design and Analysis for Small Wind Turbine Blade (초소형 풍력발전용 블레이드에 대한 구조설계 몇 해석)

  • Lee, Seung-Pyo;Kang, Ki-Weon;Chang, Se-Myong;Lee, Jang-Ho
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.2
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    • pp.288-294
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    • 2010
  • In recent years, wind energy has been the world's fastest growing source of energy. This paper describes the structural design and analysis of composite blade for 2 kW-level HAWT (horizontal axis wind turbine). The aerodynamic design and force, which are required to design and analyze a composite blade structurally, are calculated through BEMT(blade element momentum theory) implemented in public code PROPID. To obtain the equivalent material properties of filament wound composite blades, the rule-of-mixture is applied using the basic material properties of fiber and matrix, respectively. Lay-up sequence, ply thickness and ply angle are designed to satisfy the loading conditions. Structural analysis by using commercial software ABAQUS is performed to compute the displacement and strength ratio of filament wound composite blades.

- The Accident Analyze of a Pointed-End Equipment for Human Error - (Human Error에 의한 첨단장비의 사고 분석 연구)

  • Yoon Yong Gu;Park Peom
    • Journal of the Korea Safety Management & Science
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    • v.6 no.4
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    • pp.39-46
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    • 2004
  • The Study lay Emphasised on to Investigate Human Related Causes of a Pointed End Equipment Accident and the Basic data for Analyzing Human-Error Prevention Program. Peter Son's Model of Human-Error Accident Causation and Cooper's Model of Safety Culture Were Applied to Analyze the Severe Cause of a Pointed End Equipment for Last 5 Years. Through to Analyzing the Cause of Equipment Accident of Human-Error, Expert's Opinion and Experience Theory Method was Reflected. The Analyses Showed What the Immature and Inexperient Error Were Major Causes of a Pointed and Equipment Accident. The Cause of Human-Error was Found with Respect to Human, Tasks, Acknowledge, Organization.

The Accident Analyze study of a Pointed- End Equipment for Human Error (Human Error에 의한 첨단장비의 사고 분석연구)

  • Yoon Yong Gu;Park Peom
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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    • pp.311-318
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    • 2004
  • The Study lay Emphasised on to Investigate Human Related Causes of a Pointed End Equipment Accident and the Basic data for Analyzing Human-Error Prevention Program. Peter Son's Model of Human-Error Accident Causation and Cooper's Model of Safety Culture Were Applied to Analyze the Severe Cause of a Pointed End Equipment for Last 5 Years. Through to Analyzing the Cause of Equipment Accident of Human-Error, Expert's Opinion and Experience theory Method was Reflected. The Analyses Showed What the Immature and Inexperient Error Were Major Causes of a Pointed and Equipment Accident The Cause of Human-Error was Found with Respect to Human, Tasks, Acknowledge, Organization.

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A Study on the Quality of Variable Space for the Museum Space - Focused on Educational Space - (뮤지엄 공간의 가변적 활용 특성에 관한 연구 - 교육공간을 중심으로 -)

  • Zheng, Hua;Lee, Sung-Hoon
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2008.05a
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    • pp.220-225
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    • 2008
  • Museum has been advanced according to the change of the society, playing a role of social education for people as a public place. However, many museum have limited which does not allow the museum to act various roles for public needs such as resting, entertaining, educating. Accordingly, this research has intention to solve the problem that the museum cannot satisfy public various needs by functional adaptation of the space; the theory of variable space. The objective of this research is to try to find the problems and solutions from museum space through research about Spatial variability and to analyze expression special quality of museum that is used as variable. Therefore, this research is to lay the foundation of Variable application technique of educational space of museum hereafter.

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On buckling analysis of laminated composite plates using a nonlocal refined four-variable model

  • Shahsavari, Davood;Karami, Behrouz;Janghorban, Maziar
    • Steel and Composite Structures
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    • v.32 no.2
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    • pp.173-187
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    • 2019
  • This study is concerned with the stability of laminated composite plates modelled using Eringen's nonlocal differential model (ENDM) and a novel refined-hyperbolic-shear-deformable plate theory. The plate is assumed to be lying on the Pasternak elastic foundation and is under the influence of an in-plane magnetic field. The governing equations and boundary conditions are obtained through Hamilton's principle. An analytical approach considering Navier series is used to fine the critical bucking load. After verifying with existing results for the reduced cases, the present model is then used to study buckling of the laminated composite plate. Numerical results demonstrate clearly for the first time the roles of size effects, magnetic field, foundation parameters, moduli ratio, geometry, lay-up numbers and sequences, fiber orientations, and boundary conditions. These results could be useful for designing better composites and can further serve as benchmarks for future studies on the laminated composite plates.

On the parametric instability of multilayered conical shells using the FOSDT

  • Lair, John;Hui, David;Sofiyev, Abdullah H.;Gribniak, Viktor;Turan, Ferruh
    • Steel and Composite Structures
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    • v.31 no.3
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    • pp.277-290
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    • 2019
  • This paper investigates the parametric instability (PI) of multilayered composite conical shells (MLCCSs) under axial load periodically varying the time, using the first order shear deformation theory (FOSDT). The basic equations for the MLCCSs are derived and then the Galerkin method is used to obtain the ordinary differential equation of the motion. The equation of motion converted to the Mathieu-Hill type differential equation, in which the DI is examined employing the Bolotin's method. The expressions for left and right limits of dimensionless parametric instability regions (PIRs) of MLCCSs based on the FOSDT are obtained. Finally, the influence of various parameters; lay-up, shear deformations (SDs), aspect ratio, as well as loading factors on the borders of the PIRs are examined.

STUDY OF YOUNG INEQUALITIES FOR MATRICES

  • M. AL-HAWARI;W. GHARAIBEH
    • Journal of applied mathematics & informatics
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    • v.41 no.6
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    • pp.1181-1191
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    • 2023
  • This paper investigates Young inequalities for matrices, a problem closely linked to operator theory, mathematical physics, and the arithmetic-geometric mean inequality. By obtaining new inequalities for unitarily invariant norms, we aim to derive a fresh Young inequality specifically designed for matrices.To lay the foundation for our study, we provide an overview of basic notation related to matrices. Additionally, we review previous advancements made by researchers in the field, focusing on Young improvements.Building upon this existing knowledge, we present several new enhancements of the classical Young inequality for nonnegative real numbers. Furthermore, we establish a matrix version of these improvements, tailored to the specific characteristics of matrices. Through our research, we contribute to a deeper understanding of Young inequalities in the context of matrices.

Theory of the Dead's Mind: Does the Mind of the Dead Transcend Time and Space? (죽은 사람의 마음 이론: 죽은 사람의 마음은 시공간을 초월하는가?)

  • Kim, Euisun;Kim, Sung-Ho
    • Korean Journal of Cognitive Science
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    • v.29 no.2
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    • pp.105-120
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    • 2018
  • Current neuroscience views the mind-body problem from the monistic perspective which claims that the human mind is the result of brain activity and that the mind shuts down when the brain does. However, a considerable number of lay people still believe in the existence of the soul and the afterlife, concepts that are hard to explain from the monistic perspective. This study examines whether lay people think that the mind of the dead is capable of exceeding the physical constraints if they believe that such mind exists. After reading one of three vignettes which describes the state of the protagonist as alive, dead, or brain dead, the participants evaluated the protagonist's general mental capacity and transcendental ability to obtain new information. The participants rated that the dead protagonist had more 'transcendental ability to obtain new information' than the alive one if they evaluated high general mental capacity to the protagonist. In addition, unlike the alive condition, in the dead and the brain dead condition, there was a correlation between the general mind capacity rating and the transcendental ability rating. The results suggest that lay people expect the mind of the alive and the dead to be different, as they believe the latter's general mind capacity connotes transcendental ability. We also found that the participants' religiosity affected their beliefs about the transcendental ability of dead person.