• 제목/요약/키워드: Analytical Techniques

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A rapid assessment methodology for bridges damaged by truck strikes

  • Stull, C.J.;Earls, C.J.
    • Steel and Composite Structures
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    • v.9 no.3
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    • pp.223-237
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    • 2009
  • The present research aims to develop a methodology to rapidly assess bridges with damage to the superstructure, caused by overheight trucks or lower-than-average overhead clearance. Terrestrial laser scanning and image processing techniques are combined with the finite element method to arrive at an analytical model which is more accurate, with respect to the complex geometrical aspects of the bridge in its damaged configuration. ""Virtual load testing"" may subsequently be carried out on this analytical model to determine the reserve capacity of the structure in an objective manner.

Industry's Response to the Green Movement

  • Little, Barry F.P.
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.1075-1078
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    • 1995
  • This paper describes how industry has responded to the environmental challenge. Benefits include compliance with environmental legislation; genuine reductions to environmental impact; sustainable improvements to profitability in the face of increased competitive pressure. National and international Standards for environmental management offer security and direction for a company wishing to improve environmental performance and coupled with a waste minimisation strategy many financial and environmental benefits can be achieved. Introduction of new technical skills, techniques and worker understanding to aid motivation is an essential component of such a strategy. Monitoring and targeting has a key role to play in the establishment of improved environmental performance.

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The Development of a finite-Element Modelling and Component Mode Synthesis Method for High-Speed railway Passenger Cars (고속전철 객차를 위한 유한요소모델링 및 모드합성기법의 개발)

  • 장경진;김홍준;이상민;박영필
    • Proceedings of the KSR Conference
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    • 1998.05a
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    • pp.233-240
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    • 1998
  • In the design of the high-speed railway vehicles of low noise and vibration characteristics, it is desirable to develop efficient and systematic procedures for analyzing large structures. In this paper, some finite-element modelling techniques and an efficient analytical method are proposed for this purpose. The analytical method is based on substructuring approach such as a free-interface method and a generalized synthesis algorithm. In final, the proposed approaches are applied to the finite-element modelling, modal analysis and subsequent model updating procedures of the high-speed railway intermediate trailers.

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Analytical Study to Determine the Dynamic Property of Control Equipment Room using LRB (납-고무베어링을 적용한 제어장치의 동적평가를 위한 해석적 연구)

  • 김우범;김대곤;이경진;박병구
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.473-480
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    • 2003
  • In these days, The base isolation system is often used improve the seismic capacity of the structure Instead of conventional techniques of strengthening the structural members. The purpose of this study is to evaluate dynamic property evaluation of control equipment using Lead Rubber Bearing. In this study, analysis numerical was performed to determine the optimal dynamic property of lead rubber bearing and damper which minimize the response of base from in main control room. Also the analytical results was composed with the test results peformed in previous study

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Introduction of Korea Oil Identification System(KOIS) (우리나라의 해상유출물질 감식.분석기법 연구)

  • Lee, Y.S.;Lee, S.J.;Kim, C.S.;Oh, H.J.;Kim, H.G.
    • Proceedings of KOSOMES biannual meeting
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    • 2006.05a
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    • pp.85-92
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    • 2006
  • Crude oil is complex mixture if thousands of different organic compound formed from a variety of organic materials that are chemically converted under differing geological conditions over long periods of time. Also oil composition varies according to crude source, refining, processing, handling and storage. The oil fingerprint method is application if specific knowledge of petrochemicals and use if sophisticated analytical equipment and techniques to identify the source(s) if oil pollution. KCG currently utilizes four primary analytical techniques: Gas Chromatography (GC), Fluorescence Spectroscopy(FL), Infrared Spectroscopy(IR) and Gas Chromatography mass spectrometer(GC/MS). Of all these techniques, GC technique are most widely used Gas Chromatography is used as a primary analytical method because high reliableness, high separating efficiency and repeatability.

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THE RELIABLE MODIFIED OF ADOMIAN DECOMPOSITION METHOD FOR SOLVING INTEGRO-DIFFERENTIAL EQUATIONS

  • Hamoud, Ahmed A.;Ghadle, Kirtiwant P.
    • Journal of the Chungcheong Mathematical Society
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    • v.32 no.4
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    • pp.409-420
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    • 2019
  • In this article, we discussed semi-analytical approximated methods for solving mixed Volterra-Fredholm integro-differential equations, namely: Adomian decomposition method and modified Adomian decomposition method. Moreover, we prove the uniqueness results and convergence of the techniques. Finally, an example is included to demonstrate the validity and applicability of the proposed techniques.

An Analytical Study on the Anchorage Design in Exterior R/C Beam-Column Connections (R/C조 외측 보-기둥 접합부의 정착설계에 대한 해석적 연구)

  • 최기봉
    • Computational Structural Engineering
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    • v.5 no.4
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    • pp.133-142
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    • 1992
  • An analytical model was developed for predicting the pullout behavior of straight beam longitudinal bars anchored at exterior beam-column connections. The model incorporates a local bond constitutive simulation capable of considering the effects of anchored bar diameter, yield strength and the spacing, concrete compressive strength, and column pressure on the bond characteristics of deformed bars in confined conditions of exterior joints. The analytical techniques adopted in this study were shown to satisfactorily predict the results of pullout tests on straight bars embedded in confined concrete specimens. An evaluation of the ACI-ASCE Committee 352 development length requirements in exterior joint conditions was made using the developed analytical approach. The results of this analytical evaluation are indicative of the conservatism of the current development length requirements in the confined conditions of exterior joints.

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Thermal Analysis on a Satellite Box during Launch Stage by Analytical Solution

  • Choi, Joon-Min;Kim, Hui-Kyung;Hyun, Bum-Seok
    • International Journal of Aeronautical and Space Sciences
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    • v.4 no.2
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    • pp.17-25
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    • 2003
  • Simple methods are developed to predict temperatures of a satellite box during launch stage. The box is mounted on outer surface of satellite and directly exposed to space thermal environment for the time period from fairing jettison to separation. These simple methods are to solve a 1st order ordinary differential equation (ODE) which is simplified from the governing equation after applying several assumptions. The existence of analytical solution for the 1st order ODE is determined depending on treatment of time-dependent molecular heating term. Even for the case that the analytical solution is not available due to the time dependent term, the 1st order ODE can be solved by relatively simple numerical techniques. The temperature difference between two different approaches (analytical and numerical solutions) is relatively small (Jess than $1^{\circ}C$ along the time line) when they are applied to STSAT-I launch scenario. The present methods can be generally used as tools to quickly check whether a satellite box is safe against space environment during the launch stage for the case that the detailed thermal analysis is not available.

Analytical solution of a contact problem and comparison with the results from FEM

  • Oner, Erdal;Yaylaci, Murat;Birinci, Ahmet
    • Structural Engineering and Mechanics
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    • v.54 no.4
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    • pp.607-622
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    • 2015
  • This paper presents a comparative study of analytical method and finite element method (FEM) for analysis of a continuous contact problem. The problem consists of two elastic layers loaded by means of a rigid circular punch and resting on semi-infinite plane. It is assumed that all surfaces are frictionless and only compressive normal tractions can be transmitted through the contact areas. Firstly, analytical solution of the problem is obtained by using theory of elasticity and integral transform techniques. Then, finite element model of the problem is constituted using ANSYS software and the two dimensional analysis of the problem is carried out. The contact stresses under rigid circular punch, the contact areas, normal stresses along the axis of symmetry are obtained for both solutions. The results show that contact stresses and the normal stresses obtained from finite element method (FEM) provide boundary conditions of the problem as well as analytical results. Also, the contact areas obtained from finite element method are very close to results obtained from analytical method; disagree by 0.03-1.61%. Finally, it can be said that there is a good agreement between two methods.

Analytical solution and experimental study of membrane penetration in triaxial test

  • Ji, Enyue;Zhu, Jungao;Chen, Shengshui;Jin, Wei
    • Geomechanics and Engineering
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    • v.13 no.6
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    • pp.1027-1044
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    • 2017
  • Membrane penetration is the most important factor influencing the measurement of volume change for triaxial consolidated-drained shear test for coarse-grained soil. The effective pressure p, average particle size $d_{50}$, thickness $t_m$ and elastic modulus $E_m$ of membrane, contact area between membrane and soil $A_m$ as well as the initial void ratio e are the major factors influencing membrane penetration. According to the membrane deformation model given by Kramer and Sivaneswaran, an analytical solution of the membrane penetration considering the initial void ratio is deduced using the energy conservation law. The basic equations from theory of plates and shells and the elastic mechanics are employed during the derivation. To verify the presented solution, isotropic consolidation tests of a coarse-grained soil are performed by using the method of embedding different diameter of iron rods in the triaxial samples, and volume changes due to membrane penetration are obtained. The predictions from presented solution and previous analytical solutions are compared with the test results. It is found that the prediction from presented analytical solution agrees well with the test results.