• 제목/요약/키워드: integral distribution

검색결과 427건 처리시간 0.019초

Impact of composite patch on the J-integral in adhesive layer for repaired aluminum plate

  • Kaci, D. Ait;Madani, K.;Mokhtari, M.;Feaugas, X.;Touzain, S.
    • Advances in aircraft and spacecraft science
    • /
    • 제4권6호
    • /
    • pp.679-699
    • /
    • 2017
  • The aim of this study is to perform a finite element analysis of the Von Mises stresses distribution in the adhesive layer and of the J-Integral for a damaged plate repaired by a composite patch. Firstly, we study the effect of the fiber orientation, especially the position of the layers that have orientation angle different of $0^{\circ}$ from the first layer which is in all cases of our study oriented at ($0^{\circ}$) on the J-Integral. Secondly, we evaluate the effects of the mechanical properties of the patch and the use of a hybrid patch on the reduction of stresses distribution and J-Integral. The results show clearly that the stacking sequence for the composite patch must be selected to absorb optimally the stresses from the damaged area and to position the various layers of the composite under the first layer whose fibers orientation will remain in all cases equal to $0^{\circ}$. The use of a hybrid composite reduces significantly the J-Integral and the stresses in both damaged plate and the adhesive layer.

Some Properties of Complex Uncertain Process

  • You, Cuilian;Xiang, Na
    • Industrial Engineering and Management Systems
    • /
    • 제15권2호
    • /
    • pp.143-147
    • /
    • 2016
  • Uncertainty appears not only in real quantities but also in complex quantities. Complex uncertain process is essentially a sequence of complex uncertain variables indexed by time. In order to describe complex uncertain process, a formal definition of complex uncertain distribution is given in this paper, as well as the concepts of independence and variance. In addition, some properties of complex uncertain integral are presented.

Probability Integral of the Inverted Dirichlet Distribution with Application

  • Kim, Kee-Young
    • Journal of the Korean Statistical Society
    • /
    • 제13권1호
    • /
    • pp.25-31
    • /
    • 1984
  • A technique which has been used for the evaluation of certain kinds of multiple integrals, viz., the technique of imcomplete gamma function operators, is employed and extended to the case where the parameters and arguments are non-equal and non-integer for the probability integral of the inverted Dirichlet distribution. Several types of recurrence formulas have been developed for the tail probabilities and a subset selection procedure in ranking variances is discussed as an application.

  • PDF

Non-Gaussian features of dynamic wind loads on a long-span roof in boundary layer turbulences with different integral-scales

  • Yang, Xiongwei;Zhou, Qiang;Lei, Yongfu;Yang, Yang;Li, Mingshui
    • Wind and Structures
    • /
    • 제34권5호
    • /
    • pp.421-435
    • /
    • 2022
  • To investigate the non-Gaussian properties of fluctuating wind pressures and the error margin of extreme wind loads on a long-span curved roof with matching and mismatching ratios of turbulence integral scales to depth (Lux/D), a series of synchronized pressure tests on the rigid model of the complex curved roof were conducted. The regions of Gaussian distribution and non-Gaussian distribution were identified by two criteria, which were based on the cumulative probabilities of higher-order statistical moments (skewness and kurtosis coefficients, Sk and Ku) and spatial correlation of fluctuating wind pressures, respectively. Then the characteristics of fluctuating wind-loads in the non-Gaussian region were analyzed in detail in order to understand the effects of turbulence integral-scale. Results showed that the fluctuating pressures with obvious negative-skewness appear in the area near the leading edge, which is categorized as the non-Gaussian region by both two identification criteria. Comparing with those in the wind field with matching Lux/D, the range of non-Gaussian region almost unchanged with a smaller Lux/D, while the non-Gaussian features become more evident, leading to higher values of Sk, Ku and peak factor. On contrary, the values of fluctuating pressures become lower in the wind field with a smaller Lux/D, eventually resulting in underestimation of extreme wind loads. Hence, the matching relationship of turbulence integral scale to depth should be carefully considered as estimating the extreme wind loads of long-span roof by wind tunnel tests.

층이 있는 반무한체의 접촉하중에 의한 응력을 푸리에 적분을 이용한 해석 (Stress Analysis of a Layered Semi-infinite Solid Subjected to Contact Loading Using a Fourier Integral)

  • 안유민;박상신
    • Tribology and Lubricants
    • /
    • 제17권5호
    • /
    • pp.373-379
    • /
    • 2001
  • The problem of interest is formulating elastic contact problem of a layered semi-infinite solid in terms of Fourier integral. The plane strain problem is considered for a solid composed of homogeneous isotropic two layers with different mechanical properties. General solutions for the subsurface stress and deformation field of frictionless elastic bodies under normal loading using of Fourier transformation technique are obtained. The numerical results for the stress distribution of coated solid for some particular cases are given.

EQUIVALENT CONDITIONS OF COMPLETE MOMENT CONVERGENCE AND COMPLETE INTEGRAL CONVERGENCE FOR NOD SEQUENCES

  • Deng, Xin;Wang, Xuejun
    • 대한수학회보
    • /
    • 제54권3호
    • /
    • pp.917-933
    • /
    • 2017
  • In this paper, seven equivalent conditions of complete moment convergence and complete integral convergence for negatively orthant dependent (NOD, in short) sequences are shown under two cases: identical distribution and stochastic domination. The results obtained in the paper improve and generalize the corresponding ones of Liang et al. [10]). In addition, an extension of the Baum-Katz complete convergence theorem: six equivalent conditions of complete convergence is established.

열평형적분법에 의한 사다리꼴단면의 직선휜에서의 열전달해석 (Heat Transfer Analysis in a Straight Fin of Trapezoidal Profile by the Heat Balance Integral Method)

  • 조종철;조진호
    • 대한설비공학회지:설비저널
    • /
    • 제11권3호
    • /
    • pp.1-8
    • /
    • 1982
  • When exact analytical solutions to certain type of heat conduction problems are quite cumbersome or not obtainable, it is important to introduce approximate analytical methods which are simple and useful compared with numerical methods. In this study, therefore, the Heat Balance Integral Method is applied to analysis of steady-state conduction in a straight fin of trapezoidal profile, and the two-dimensional temperature distribution in the fin and the approximate fin efficiency are obtained. Results are compared with those by the one- dimensional analysis and two-dimensional numerical analysis for a wide range of Biot numbers. It is shown that the two-dimensional temperature distribution obtained by the integral method is in good agreement with that by the finite element method at Biot numbers for which the result by the one-dimensional analysis is unreliable.

  • PDF

ESTIMATION OF A MODIFIED INTEGRAL ASSOCIATED WITH A SPECIAL FUNCTION KERNEL OF FOX'S H-FUNCTION TYPE

  • Al-Omari, Shrideh Khalaf Qasem
    • 대한수학회논문집
    • /
    • 제35권1호
    • /
    • pp.125-136
    • /
    • 2020
  • In this article, we discuss classes of generalized functions for certain modified integral operator of Bessel-type involving Fox's H-function kernel. We employ a known differentiation formula of Fox's H-function to obtain the definition and properties of the distributional modified Bessel-type integral. Further, we derive a smoothness theorem for its kernel in a complete countably multi-normed space. On the other hand, using an appropriate class of convolution products, we derive axioms and establish spaces of modified Boehmians which are generalized distributions. On the defined spaces, we introduce addition, convolution, differentiation and scalar multiplication and further properties of the extended integral.

수학적 연결성을 고려한 연속확률분포단원의 지도방안 연구 (A Study on Teaching Continuous Probability Distribution in Terms of Mathematical Connection)

  • 황석근;윤정호
    • 대한수학교육학회지:학교수학
    • /
    • 제13권3호
    • /
    • pp.423-446
    • /
    • 2011
  • 학교수학에서 정적분과 치환적분법의 개념은 확률밀도함수의 도입, 연속확률변수의 기댓값, 정규분포의 표준화와 관련하여 수학적 연결성을 가진다. 그러나 개정교육과정의 '미적분과 통계 기본', '적분과 통계' 과목의 교육과정해설서와 검인정 교과서 및 익힘책에서 적분단원과 통계단원 사이의 수학적 연결성 고려가 어려움을 발견하였다. 본 연구는 학교수학에서 확률밀도함수의 도입, 연속확률변수의 기댓값, 정규분포의 표준화에 대하여 적분단원과의 수학적 연결성을 고려한 지도방안 마련을 목적으로 한다. 세개념에 대한 학생대상 실태조사와 개정교육과정의 교육과정해설서, 교과서, 익힘책, 그리고 국내 외 통계학(확률론) 도서(국내 13종, 국외 22종)의 내용을 비교하였다. 이를 바탕으로 세 개념에 대한 지도내용을 개발하여 실제 수업에 적용해보았고, 교육과정개정이나 교과서의 내용구성 변화에 대한 시사점을 발견하여 그 결과를 제언하였다.

  • PDF

On the Vibration Analysis of the Floating Elastic Body Using the Boundary Integral Method in Combination with Finite Element Method

  • K.T.,Chung
    • 대한조선학회지
    • /
    • 제24권4호
    • /
    • pp.19-36
    • /
    • 1987
  • In this research the coupling problem between the elastic structure and the fluid, specially the hydroelastic harmonic vibration problem, is studied. In order to couple the domains, i.e., the structural domain and the fluid domain, the boundary integral method(direct boundary integral formulation) is used in the fluid domain in combination with the finite element method for the structure. The boundary integral method has been widely developed to apply it to the hydroelastic vibration problem. The hybrid boundary integral method using eigenfunctions on the radiation boundaries and the boundary integral method using the series form image-functions to replace the even bottom and free surface boundaries in case of high frequencies have been developed and tested. According to the boundary conditions and the frequency ranges the different boundary integral methods with the different idealizations of the fluid boundaries have been studied. Using the same interpolation functions for the pressure distribution and the displacement the two domains have been coupled and using Hamilton principle the solution of the hydroelastic have been obtained through the direct minimizing process. It has become evident that the finite-boundary element method combining with the eigenfunction or the image-function method give good results in comparison with the experimental ones and the other numerical results by the finite element method.

  • PDF