• Coupled systems mechanics
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• 제6권1호
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• pp.97-111
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• 2017

The present paper reports an analytical study of delamination fracture in the Mixed Mode Flexure (MMF) functionally graded beam with considering the material non-linearity. The mechanical behavior of MMF beam is modeled by using a non-linear stress-strain relation. It is assumed that the material is functionally graded along the beam height. Fracture behavior is analyzed by the J-integral approach. Non-linear analytical solution is derived of the J-integral for a delamination located arbitrary along the beam height. The J-integral solution derived is verified by analyzing the strain energy release rate with considering the non-linear material behavior. The effects of material gradient, crack location along the beam height and material non-linearity on the fracture are evaluated. It is found that the J-integral value decreases with increasing the upper crack arm thickness. Concerning the influence of material gradient on the non-linear fracture, the analysis reveals that the J-integral value decreases with increasing the ratio of modulus of elasticity in the lower and upper edge of the beam. It is found also that non-linear material behavior leads to increase of the J-integral value. The present study contributes for the understanding of fracture in functionally graded beams that exhibit material non-linearity.

• 한국안전학회지
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• 제13권2호
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• pp.136-144
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• 1998

FTA is the most commonly used method among quantitative safety assessment. In case that the observing system become larger, a lot of terms should be calculated to accomplish FTA through complicated process. Many methods have been tried to reduce time, one of tries is How to calculate the reliability using graph theory after changing W to graph. This paper suggests an algorithm that can calculate more rapidly reliability and outset of system expressed by non-linear graph as like as FTA or CCA.

• Steel and Composite Structures
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• 제23권3호
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• pp.263-271
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• 2017

A theoretical study was carried-out of mode II delamination fracture behavior of the End Loaded Split (ELS) functionally graded beam configuration with considering the material non-linearity. The mechanical response of ELS was modeled analytically by using a power-law stress-strain relation. It was assumed that the material is functionally graded transversally to the beam. The non-linear fracture was investigated by using the J-integral approach. Equations were derived for the crack arm curvature and zero axes coordinate that are needed for the J-integral solution. The analysis developed is valid for a delamination crack located arbitrary along the beam height. The J-integral solution was verified by analyzing the strain energy release rate with considering material non-linearity. The effects of material gradient, non-linear material behavior and crack location on the fracture were evaluated. The solution derived is suitable for parametric analyses of non-linear fracture. The results obtained can be used for optimization of functionally graded beams with respect to their mode II fracture performance. Also, such simplified analytical models contribute for the understanding of delamination fracture in functionally graded beams exhibiting material non-linearity.

• 한국농공학회지
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• 제41권1호
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• pp.106-114
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• 1999

This paper explores the geometrical non-linear behavior of the simply supported tapered beams subject to the trapezoidal distributed load and end moments. In order to apply the Bernoulli -Euler beam theory to this tapered beam, the bending moment equation on any point of the elastical is obtained by the redistribution of trapezoidal distributed load. On the basis of the bending moment equation and the BErnoulli-Euler beam theory, the differential equations governging the elastical of such beams are derived and solved numerically by using the Runge-Jutta method and the trial and error method. The three kinds of tapered beams (i.e. width, depth and square tapers) are analyzed in this study. The numerical results of non-linear behavior obtained in this study from the simply supported tapered beams are appeared to be quite well according to the results from the reference . As the numerical results, the elastica, the stress resultants and the load-displacement curves are given in the figures.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.201-208
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• 2000

This paper explores the non-linear behavior of tapered beam subjected to a floating concentrated load. For applying the Bernoulli-Euler beam theory to this beam, the bending moment at any point of elastica is obtained from the final equilibrium state. By using the bending moment equation and the Bernoulli-Euler beam theory, the differential equations governing the elastica of clamped-roller beam are derived, and solved numerically. Three kinds of tapered beam types are considered. The numerical results of the non-linear behavior obtained in this study are agreed quite well to the results obtained from the laboratory-scale experiments.

• 한국농공학회지
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• 제42권2호
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• pp.108-114
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• 2000

This paper explores the non-linear behavior of tapered beam subjected to a floating concentration load. For applying the Bernoulli-Euler beam theory to this beam, the bending moment at any point of elastical is obtained from the final equilibrium stage. By using the bending moment equation and the Bernoulli-Euler beam theory, the differential equations governing the elastica of simple beam are derived , and solved numberically . Three kinds of tapered beam types are considered . The numerical results of the non-linear behavior obtained in this study are agreed quite well to the results obtained from the laboratory-scale experiments.

• 한국식생활문화학회지
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• 제23권5호
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• pp.605-615
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• 2008

The principal objective of this study was to categorize service attributes on the basis of the asymmetric and non-linear relationship existing between service attributes and customer satisfaction. Researchers generally assume that service attribute performances and customer satisfaction are both symmetrical and linear. That is to say, improvements in attribute performance will inevitably result in increased customer satisfaction. However, this is not always the case. Certain attributes have been shown not to create satisfaction even when improved, and others do not create dissatisfaction even when their performance ratings become negative. Understanding this relationship is crucial not only to researchers, but also to service managers. Service managers can arrange their priorities with regard to which attributes must be improved or promoted first, in an environment of limited technical, financial, and human resources. Many studies into this asymmetric and non-linear relationship have recently been conducted, beginning with Herzberg's motivation-hygiene theory (1976) and the disconfirmation theory, which was eventually developed into Kano's model (1984). This study attempted to determine the impact level of service attributes on incidents of satisfaction or dissatisfaction. It used 30 service attributes generated by Park (2008) in the CIT research into family restaurants. The data were collected from 600 participants, 300 incidences of satisfaction and 300 incidents of dissatisfaction, via an online survey. The t-test was used to confirm the difference between the satisfaction group's and dissatisfaction group's attributes. 11 attributes were found to be significant at a level of p>0.05. This indicates that the 11 attributes exerted different impacts on satisfaction and dissatisfaction, which confirmed the asymmetric and non-linear relationship. 14 attributes were categorized into the core service, 1 attribute into the quality service, 7 attributes into the basic service, and 8 attributes into the neutral service. Strategic customer service management was recommended for the 'A' family restaurant as an example, on the basis of the asymmetric and non-linear relationship and the characteristics of the four service factors.

• Structural Engineering and Mechanics
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• 제88권5호
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• pp.439-449
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• 2023

Non-linear vibration characteristics of functionally graded CNT-reinforced composite (FG-CNTRC) cylindrical shell panel on elastic foundation have not been sufficiently examined. In this situation, this study aims at the profound numerical investigation of the non-linear vibration response of FG-CNTRC cylindrical panels on Winkler-Pasternak foundation by introducing an accurate and effective 2-D meshfree-based non-linear numerical method. The large-amplitude free vibration problem is formulated according to the first-order shear deformation theory (FSDT) with the von Karman non-linearity, and it is approximated by Laplace interpolation functions in 2-D natural element method (NEM) and a non-linear partial derivative operator H_NL. The complex and painstaking numerical derivation on the curved surface and the crucial shear locking are overcome by adopting the geometry transformation and the MITC3+ shell elements. The derived nonlinear modal equations are iteratively solved by introducing a three-step iterative solving technique which is combined with Lanczos transformation and Jacobi iteration. The developed non-linear numerical method is estimated through the benchmark test, and the effects of foundation stiffness, CNT volume fraction and functionally graded pattern, panel dimensions and boundary condition on the non-linear vibration of FG-CNTRC cylindrical panels on elastic foundation are parametrically investigated.

• 한국유통학회지:유통연구
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• 제10권2호
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• pp.49-72
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• 2005

상호의존성은 유통경로상에 존재하는 기본적 특성으로서 오랫동안 유통분야에서 관련연구들이 활발하게 진행되어 왔다. 특히 갈등은 유통경로상의 거래관계를 특징짓는 주요 특성으로서 상호의존성과 갈등 간 관계를 규명하는 것은 의미하는 바가 크다. 그러나 사회학 분야에서는 상호의존성과 갈등 간 관계를 설명하는 상반된 이론이 존재하며, 마케팅 분야에서도 상호의존성과 갈등 간 관계에 대해서 상반된 연구결과가 제시되었다. 이에 본 연구에서는 상호의존성과 갈등 간 관계에 대해 대립된 설명을 하고 있는 쌍무적 억제이론과 갈등나선형이론 등의 사회학 이론을 활용하여 붙균형적 상호의존성과 갈등간 비선형적 관계를 제안하고, 이를 위해 소방관련 전문공사업체들과 공급업체들로부터 설문데이타를 수집하여 불균형적 상호의존성과 갈등간 역U형태의 관계가 있음을 증명하고자 한다. 분석결과 구매업체집단과 공급업체집단 모두에서 상호의존성의 총합이 높을 때 불균형적 상호의전성과 갈등간 비선형적 관계가 통제적으로 유의미하게 도출되었다. 마지막으로 몇 가지 학문적 시사점들과 한계점 및 향후 연구 과제를 제시하였다.

• 한국지진공학회논문집
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• 제5권5호
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• pp.1-11
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• 2001

파랑하중 및 지진하중을 받는 스틸자켓 해양구조물의 기하학적 비선형성을 고려한 정적 및 동적해석을 위한 주처리 및 전/후처리 프로그램을 개발하고 이를 이용한 해석결과를 제시한다. 본 논문에서는 스틸자켓을 기하학적 비선형성을 고려한 공간뼈대구조로 모델링하여, 유체 동하중은 선형파이론과 Stokes 5차이론에 의하여 구해진 파의 속도와 가속도를 이용하여 Morison 방정식에 근거한 파력을 계산한다. JONSWAP 스펙트럼을 이용하여 특정 유효파공의 크기에 따라 불규칙파를 생성하며, 지진하중은 인공지진 가속도 프로그램(SIMQKE)을 이용하여 목표응답스펙트럼에 맞는 다양한 형태의 인공지진 가속도를 이용하여 동적해석법을 제시한다. 선형 동적 해석을 위하여 직접 적분법과 모드 중첩법을 사용하며, 비선형 동적해석시에는 직접 적분법을 적용한다. 또한, 스틸자켓의 극한거동을 추적하기 위하여 뼈대구조의 소성힌지 해석법을 적용한다. 연계논문 에서는 전/후처리 프로그램의 내용을 설명하고 해양환경하중을 받는 스틸자켓의 정적 및 동적해석 결과를 제시한다.