• Title/Summary/Keyword: the continuous method

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A Free Vibration Analysis of the Continuous Circular Cylindrical Shell with the Multiple Simple Supports Using the Receptance Method (동적응답법을 이용한 다점 단순지지된 연속원통셸의 자유진동 해석)

  • 이영신;한창환
    • Journal of KSNVE
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    • v.10 no.6
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    • pp.998-1008
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    • 2000
  • The continuous circular cylindrical shells are widely used for the high performance structures of aircraft, spacecraft, missile, nuclear fuel rod shell etc.. In this paper, a method for the free vibration analysis of the continuous circular cylindrical shells with the multiple simple supports is developed by using the receptance method. With this method, the vibrational characteristics of the continuous system is analyzed by considering as a combined structure. The system receptance is also derided by the application of the equilibrium of forces and the continuity of displacements at the support points. The natural frequencies and mode shapes are calculated numerically and they are compared with the FEM results to improve the reliability of analytical solution. Numerical results on the 4-equal-span continuous circular cylindrical shell are presented in this paper.

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The Study of Algorithm for the Path generation in the Obstacles Environment (장애물 환경에서 경로 생성을 위한 알고리즘 연구)

  • 황하성;양승윤;이만형
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.430-433
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    • 1996
  • In This paper, we design the developed path generation method which is named that CBPM(Continuous path generation method Based artificial Potential field) that is able to be used in the obstacles environment. This CBPM is designed so that it puts together two obstacle avoidance algorithm-the continuous path generation method and the artificial potential field method. Here, the continuous path generation method generate the safety path using continuous path curvature. But, this method has demerits when used in obstacles environment in which are closely located. Another method which is named the artificial potential field method generates the path with the artificial potential field in the obstacles environment. But, APFM has local minima in certain places and unnecessarily calculates the path in which obstacles are not located. So, the developed path generation method, CBPM, is suggested and performances in many different obstacles environments are shown by using computer simulation.

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A Study of the Tendon Profile of a PSC Continuous Beam Able to Resist the Negative Bending Moment of Continuous Intergirders (거더 연속부의 부모멘트 제어에 효과적인 PSC 연속보의 텐던 배치에 관한 연구)

  • Kim, Eui Hun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.6
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    • pp.617-625
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    • 2021
  • The problems associated with the continuous method of a domestically improved prestressed concrete (PSC) girder and the bending moment of a continuous tendon were studied. Based on the results, a continuous tendon model was proposed that can resist the negative bending moment of an intergirder. This model lowers the anchorage of the continuous tendon as far as possible under the girder, and extends the tendon section arranged under the girder. This method reduces the PS's bending moment in the middle of the span, but maximizes it in the intergirder. This continuous tendon model can offer a suitable method for continuity before manufacturing a composite, which requires a higher design bending moment in the intergirder than in the middle of the span.

On the Description of Constrained Static Behavior of Continuous System

  • Eun, Hee-Chang;Lee, Min-Su;Bae, Chung-Yeol
    • Architectural research
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    • v.9 no.1
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    • pp.39-45
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    • 2007
  • The static behavior of continuous system is described by the elastic curve method or is approximately analyzed by a finite element method to be modeled as a discrete system. If a continuous system is constrained by linear constraints which restrict its static behavior, its behavior can be approximately described by the finite element method. It is not easy to describe the constrained behavior by continuous coordinate system. Starting from the generalized inverse method provided by Eun, Lee and Chung, this study is to expand the equation to the continuous systems, to perform the structural analysis of the beam under a uniform loading with interior spring supports, and to investigate the validity of the proposed method through applications.

Vibration Analysis of the Continuous Circular Cylindrical Shell with the Clamped-clamped Supports at Two End Edges (양단이 고정지지된 연속원통셸의 진동특성 해석)

  • 한창환;이영신
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.2
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    • pp.97-107
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    • 2002
  • The continuous circular cylindrical shells are widely used for the high performance structures of aircraft, spacecraft, missile, nuclear fuel rod shell and so on. In this paper, a method for the vibrational analysis of the continuous circular cylindrical shells with the clamped-clamped supports at two end edges is developed by using the modal expansion method. Forces and/or moments acting on the shell surface are expressed in terms of the Dirac Delta Function. Frequency equation of the continuous shell is also derided by the application of the equilibrium of forces and the continuity of displacements at the boundary. Natural frequencies of the continuous shell are calculated numerically with mathematica 3.0 and they are compared with FEM results from the ANSYS 5.3 to improve the reliability of analytic solutions. Mode shares obtained by the FEM are Presented in this paper.

Design Method for Continuous IPC Girder bridges (IPC 거더의 연속화 설계 방안)

  • 한만엽;황의승;박준범
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1007-1012
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    • 2000
  • This study is to present a design method using continuous tendons in IPC girders. Present design methods use just concrete to make continuity between girders. In these design methods cracks occur in almost every joint area of girders. This means that these girders act as simple beam instead of continuous beams. The design method which is presented here uses continuous tendons between girders. In this method the cracks could be restrained. So the girders behave as continuous beams, which this method allows the span length gets longer than simple girders and also the section height could get lower. In this way the number of piers and the weight of super structure could be reduced which means the construction cost could also be reduced.

Closed-form and numerical solution of the static and dynamic analysis of coupled shear walls by the continuous method and the modified transfer matrix method

  • Mao C. Pinto
    • Structural Engineering and Mechanics
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    • v.86 no.1
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    • pp.49-68
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    • 2023
  • This study investigates the static and dynamic structural analysis of symmetrical and asymmetrical coupled shear walls using the continuous and modified transfer matrix methods by idealizing the coupled shear wall as a three-field CTB-type replacement beam. The coupled shear wall is modeled as a continuous structure consisting of the parallel coupling of a Timoshenko beam in tension (with axial extensibility in the shear walls) and a shear beam (replacing the beam coupling effect between the shear walls). The variational method using the Hamilton principle is used to obtain the coupled differential equations and the boundary conditions associated with the model. Using the continuous method, closed-form analytical solutions to the differential equation for the coupled shear wall with uniform properties along the height are derived and a numerical solution using the modified transfer matrix is proposed to overcome the difficulty of coupled shear walls with non-uniform properties along height. The computational advantage of the modified transfer matrix method compared to the classical method is shown. The results of the numerical examples and the parametric analysis show that the proposed analytical and numerical model and method is accurate, reliable and involves reduced processing time for generalized static and dynamic structural analysis of coupled shear walls at a preliminary stage and can used as a verification method in the final stage of the project.

Combining Independent Permutation p Values Associated with Mann-Whitney Test Data

  • Um, Yonghwan
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.7
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    • pp.99-104
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    • 2018
  • In this paper, we compare Fisher's continuous method with an exact discrete analog of Fisher's continuous method from permutation tests for combining p values. The discrete analog of Fisher's continuous method is known to be adequate for combining independent p values from discrete probability distributions. Also permutation tests are widely used as alternatives to conventional parametric tests since these tests are distribution-free, and yield discrete probability distributions and exact p values. In this paper, we obtain permutation p values from discrete probability distributions using Mann-Whitney test data sets (real data and hypothetical data) and combine p values by the exact discrete analog of Fisher's continuous method.

Investigation of Prior Technology and Development Case for Consecutive Excavation Technique of Shield TBM (연속굴착 쉴드 TBM 기술 관련 해외기술 및 개발사례 조사)

  • Mun-Gyu Kim;Jung-Woo Cho;Hyeong-seog Cha
    • Tunnel and Underground Space
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    • v.33 no.5
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    • pp.299-311
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    • 2023
  • Continuous excavation technologies are developed to improve the excavation rate of shield TBM. Continuous excavation is a technology that provides thrust to segments, excluding being installed one, to reduce tunneling downtime. This paper investigated the prior technology related to continuous excavation segments. The main technology was classified into helical segment, honeycomb segment, and conventional segment methods. The helical segment method has not been applied in actual construction yet, and the honeycomb segment method has not succeeded in commercialization. The continuous excavation method using conventional segments has been successfully demonstrated. The thrust force and operation method of the thrust jacks for the semi-continuous technology were analyzed. Continuous excavation TBM research is also progressing in Korea, and through the analysis of successful cases, the need to develop independent continuous excavation methods has been identified.