• 전산구조공학
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• 제2권2호
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• pp.53-62
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• 1989

최근에 원유와 석유제품을 저장하기 위한 지하공동의 필요성이 급증하고 있다. 지하저장공동의 동적응답을 구하기 위하여 재료비선형(탄.점소성)과 기하학적 비선형 효과를 모두 고려한 프로그램 VISDYN을 작성하여 그 유효성을 확인하였다. 프로그램 VISDIN을 이용하여 지하저장 공동의 탄.점소성 동적해석을 수행한 결과 공동을 굴착한 후 지반이 안정상태에 도달한 때의 변위와 굴착 직후의 변위는, 동적인 변위 응답에서는 차이가 거의 없음을 알 수 있었다.

• Structural Engineering and Mechanics
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• 제35권3호
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• pp.301-314
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• 2010

The paper presents the results and conclusions of dynamic load tests that were conducted on a road bridge over the Mokrzyca river in Wroclaw (Poland) made of galvanized corrugated steel plates (CSP). The critical speed magnitudes, velocity vibration, vibration frequency were determined in the paper. The dynamic analysis is extremely important, because such studies of soil-steel bridges in the range of dynamic loads are relatively seldom conducted. Conclusions drawn from the tests can be most helpful in the assessment of behaviour of this type of corrugated plate bridge with soil. In consideration of application of this type of structure in the case of small-to-medium span bridges, the conclusions from the research will not be yet generalized to all types of such solutions. The detailed reference to all type of such bridge structures would be requiring additional analysis (field tests and calculations) on the other types of soil-steel bridges.

• Geomechanics and Engineering
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• 제10권4호
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• pp.455-470
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• 2016

In ballasted railway tracks, ballast fouling due to finer material intrusion has been identified as a challenging issue in track maintenance works. In this research, deformation characteristics of crushed stone-sand mixtures, simulating fresh and fouled ballasts were studied from laboratory and a 3-D discrete element method (DEM) triaxial compression tests. The DEM simulation was performed using a recently developed DEM approach, named, Yet Another Dynamic Engine (YADE). First, void ratio characteristics of crushed stone-sand mixtures were studied. Then, triaxial compression tests were conducted on specimens with 80 and 50% of relative densities simulating dense and loose states respectively. Initial DEM simulations were conducted using sphere particles. As stress-strain behaviour of crushed stone-sand mixtures evaluated by sphere particles were different from laboratory specimens, in next DEM simulations, the particles were modeled by a clump particle. The clump shape was selected using shape indexes of the actual particles evaluated by an image analysis. It was observed that the packing behaviour of laboratory crushed stone-sand mixtures were matched well with the DEM simulation with clump particles. The results also showed that the strength properties of crushed stone deteriorate when they are mixed by 30% or more of sand, specially under dense state. The results also showed that clump particles give closer stress-strain behaviour to laboratory specimens than sphere particles.

• Coupled systems mechanics
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• 제6권4호
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• pp.501-522
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• 2017

This paper introduces a numerical procedure to incorporate elasto-plastic local deformation effects in the dynamic analysis of beams. The appealing feature is that simple beam type finite elements can be used for the global model which needs not to be altered by the localized elasto-plastic deformations. An overlapping local sophisticated 2D membrane model replaces the internal forces of the beam elements in the predefined region where the localized deformations take place. An iterative coupling technique is used to perform this replacement. Comparisons with full membrane analysis are provided in order to illustrate the accuracy and efficiency of the method developed herein. In this study, the membrane formulation is able to capture the elasto-plastic material behaviour based on the von Misses yield criterion and the associated flow rule for plane stress. The Newmark time integration method is adopted for the step-by-step dynamic analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.883-888
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• 2004

One of commercial rapid transits produces peculiar booming sound when passing through the slab-track tunnel. In order to analyze that tympanic membrane-pressing noise systematically, typical source-transfer path-response analysis was carried out. Considering the octave band of booming noise, work scope was confined to structure-borne noise analysis, especially the dynamic behaviour of railway tracks. Experimental modal analysis of railway tracks, composed of rail, rubber pad, sleeper, ballast, and ground were performed. The results shows that transversal bending modes of the rail are suspicious for the cause of the low band booming noise. Finite element analysis are made use of to match preceding experimental results, and plausible dynamic properties of track components are produced.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.137-141
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• 1993

In the case of a boring bar, the vibration amplitude is generallylarge due to its high slenderness. The boring bat is then modelled as a cantilever with dynamic force acting at the free end and a generalized model of nonlinear continous system is obtained. The Analysis of model is conducted for the specific case with a zero side cutting edge angle. The dynamic behaviour is investigated for machining processes in which the the overlap factor of regenerative effect is considered. The vibration characteristics of boring bar depth of cut rather than feed rate in given slenderness.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.810-813
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• 2004

A study on the dynamic response of single-storey steel frames equipped with a rotational friction damper is presented. Extensive testing was carried out for assessing the friction pad material, damper unit performance and foaled model frame response to lateral harmonics excitation. Numerical simulations based on non-linear time history analysis were used to evaluate the seismic behaviour of steel frames with rotational frictional damper. It Is demonstrated that using discrete friction dampers of proper parameters to link steel frame can reduce dynamic response significantly.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.85-90
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• 1997

In the stroke sensitive shock absorber, the oil path is formed along the internal cylinder surface to make the eli flow during piston's upper-lower reciprocation movement. With constraint to the conventional shock absorbers which show one dynamic characteristic curve, stroke sensitive shock absorber shows two kins of dynamic characteristic according to the stroke, In the study, analysis on the damping force generation process and dynamic behaviour characteristics of stroke sensitive shock absorber is performed, the valve characteristics being considered more precise information about design and damping performance analysis.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.817-821
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• 2008

Wind turbine requires service life of about 20 years and each components of wind turbine requires high durability, because installation and maintenance costs are more expensive than generated electricity by wind turbine. So the design of wind turbine must be verified in various condition before production step. This paper demonstrates the application of a generic methodology, based on the flexible multibody simulation technique, for the dynamic analysis of a wind turbine and its drive train. The concern of the paper is the computation of dynamic loads of wind turbine in emergency-stop condition. The finite element model is used to analyse the dynamic behaviour of the wind turbine.

• 한국정밀공학회지
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• 제14권11호
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• pp.11-16
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• 1997

In the stroke sensitive shock absorber, the oil path is formed along the internal cylinder surface to make the oil flow during the piston's upper-lower reciprocation movement. In constrast with the conventional shock absorbesr which show one dynamic characteristic curve, stroke sensitive shock absorber shows two kinds of dynamic characteristics according to the stroke. In this study, in order to obtain more precise information about design and damping performance analysis, the analysis on the damping force generation process and dynamic behaviour characteristics of stroke sensitive shock absorber are performed by considering the valve characteristics.