• 제목/요약/키워드: dynamic influence

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바닥충격음 완충재의 동탄성계수 특성 및 측정 영향인자 (A Study On the Property and Influence Factor in Measuring of the Dynamic Stiffness of Damping Materials)

  • 김경우;최현중;강재식;양관섭
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.1256-1259
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    • 2006
  • The purpose of this study was to investigate the current status and influence factor in measuring the dynamic stiffness of damping materials. The property of the dynamic stiffness of damping materials was tested and analysed in condition such as the size of test samples and the change of relative humidity in heating chamber. Test results showed that the dynamic stiffness of after-heating was lower than that of before-heating in most samples and the change of relative humidity in heating chamber got little influence of the dynamic stiffness. The resonant frequency of test sample decreased $2{\sim}7Hz$ as the decrease of the size of sample. Because it was increased that total mass per unit area of sample, the change of dynamic stiffness had little influence.

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차체의 동특성을 고려한 구동시스템의 진동모드 (Vibration Mode of the Drivesystem Considered the Vehicle Body's Dynamic Characteristics)

  • 유충준
    • 한국자동차공학회논문집
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    • 제12권2호
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    • pp.148-159
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    • 2004
  • This paper discusses vibration mode of the drivesystem considered the vehicle body's dynamic characteristics to study the influence of the vehicle body's dynamic characteristics on the vibration mode of the engine mount system and the ride quality of a vehicle. The simulation model consists of the engine mount system, the powertrain and the rigid or elastic vehicle body. Variables used in this study are the stiffnesses of an engine mount system and the excitation forces. The Goals of the study are analyzing both the vibration transmitted to the vehicle body including the drivesystem and the influence of the vehicle body's dynamic characteristics on the engine mount system. The mode of drivesystems with a rigid and a elastic vehicle body was compared. From the result of the forced vibration analysis for the drivesystem with a elastic vehicle body, it is shown that the vehicle body's dynamic characteristics influence on the engine mount system reciprocally.

Influence of creep on dynamic behavior of concrete filled steel tube arch bridges

  • Ma, Yishuo;Wang, Yuanfeng;Su, Li;Mei, Shengqi
    • Steel and Composite Structures
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    • 제21권1호
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    • pp.109-122
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    • 2016
  • Concrete creep, while significantly changing the static behaviors of concrete filled steel tube (CFST) structures, do alter the structures' dynamic behaviors as well, which is studied quite limitedly. The attempt to investigate the influence of concrete creep on the dynamic property and response of CFST arch bridges was made in this paper. The mechanism through which creep exerts its influence was analyzed first; then a predicative formula was proposed for the concrete elastic modulus after creep based on available test data; finally a numerical analysis for the effect of creep on the dynamic behaviors of a long-span half-through CFST arch bridge was conducted. It is demonstrated that the presence of concrete creep increases the elastic modulus of concrete, and further magnifies the seismic responses of the displacement and internal force in some sections of the bridge. This influence is related closely to the excitation and the structure, and should be analyzed case-by-case.

Mass perturbation influence method for dynamic analysis of offshore structures

  • Cho, Kyu Nam
    • Structural Engineering and Mechanics
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    • 제13권4호
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    • pp.429-436
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    • 2002
  • The current work presents an analysis algorithm for the modal analysis for the dynamic behaviors of offshore structures with concepts of mass perturbation influence term. The mass perturbation concept by using the term, presented in this paper offers an efficient solution procedure for dynamical response problems of offshore structures. The basis of the proposed method is the mass perturbation influence concepts associated with natural frequencies and mode shapes and mass properties of the given structure. The mathematical formulation of the mass perturbation influence method is described. New solution procedures for dynamics analysis are developed, followed by illustrative example problems, which deal with the effectiveness of the new solution procedures for the dynamic analysis of offshore structures. The solution procedures presented herein is compact and computationally simple.

Crashworthiness analysis on existing RC parapets rehabilitated with UHPCC

  • Qiu, Jinkai;Wu, Xiang-guo;Hu, Qiong
    • Computers and Concrete
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    • 제19권1호
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    • pp.87-98
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    • 2017
  • In recent year, the coat layer drops and the rebar rust of bridge parapets, which caused the structural performance degradation. In order to achieve the comprehensive rehabilitation, ultra high performance cementitious composites is proposed to existing RC parapet rehabilitation. The influence factors of UHPCC rehabilitation includes two parts, i.e., internal factors related with material, such as UHPCC layer thickness, corrosion ratio of rebars, fiber volume fraction, and external factors related with the load, such as impact speeds, impact angles, vehicle mass. The influence of the factors was analyzed in this paper based on the nonlinear finite element. The analysis results of the maximum dynamic deformation and the peak impact load of parapets revealed the influence of the internal factors and the external factors on anti-collision performance and degree degradation. This research may provide a reference for the comprehensive multifunctional rehabilitation of existing bridge parapets.

동다짐 공법의 유효다짐깊이 결정에 영향을 주는 인자 분석 (Analysis of Influence Parameters to Evaluate the Effective Depth of Improvement of Dynamic Compaction Method)

  • 김홍택;이혁진;박인준
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2004년도 춘계학술발표회
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    • pp.659-666
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    • 2004
  • Dynamic compaction has evolved as an acceptable method of site improvement by treating poor soils in situ. The method is often an economical alternative for utilizing shallow foundations and preparing subgrades for construction when compared with conventional solutions. In general, the installation purpose of dynamic compaction are to increase bearing capacity and decrease differential settlement within a specified depth of improvement. This method involves the s systematically dropping large weights onto the ground surface to compact the underlying ground. The weights used on dynamic compaction projects have been typically constructed of steel plates, sand or concrete filled steel shells, and reinforced concrete. Typically, weights range from 5-20 ton and base configurations are, circular or octagonal. In this study, the effective depth of improvement is evaluated based on the numerical analysis code, the dynamic analysis of FLAC-3D program, in order to analyze the influence parameters ; ground conditions, maximum applied load and the area of compaction plate.

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동적 피드백 공정조절에 있어 이상원인의 문제 (Problems of Assignable Causes in Dynamic Feedback Process Control)

  • 전상표
    • 대한안전경영과학회지
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    • 제7권5호
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    • pp.213-231
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    • 2005
  • Assignable causes producing temporary deviation from the underlying system can influence on process adjustment and process monitoring in dynamic feedback control system. In this paper, the influence of assignable causes on EWMA forecasts and compensatory variables are derived for a dynamic feedback control system. An example is presented to confirm the impact numerically through the analysis of a data.

중소기업의 기업가지향성, 학습지향성이 동적역량과 국제화 성과에 미치는 영향에 관한 연구: 여유자원의 조절효과를 중심으로 (The Effect of Entrepreneurial Orientation, Learning Orientation and Dynamic Capability on International Performance: Moderating Effects of Slack Resource)

  • 류동우;김기근
    • 무역학회지
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    • 제45권5호
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    • pp.161-179
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    • 2020
  • The importance of entering the international market for small and medium-sized enterprises (SMEs) has been continuously emphasized. As a way to overcome these factors, prior studies have increased interest in dynamic capability. The purpose of this study is to investigate the effects of entrepreneurial orientation, learning orientation, and dynamic capability on their international performance of SMEs. Drawing on an extensive review of the literature on dynamic capability view and internationalization, hypotheses are developed and tested using a sample of 214 SMEs in South Korea. Structural equation modeling was applied. As a result of analysis, first, dynamic capability has a significant effect on international performance. Second, entrepreneurial orientation has significant influence on dynamic capability. Third, learning orientation has significant influence on dynamic capability. Lastly, slack resource was found to moderate the relationship between dynamic capability and international performance. The results indicate that their entrepreneurial orientation and learning orientation ware driver of their dynamic capability. and that their dynamic capability was significant driver of their international performance. In the final conclusion, implications and limitations of research and suggestions for future research are discussed.

바닥충격음 완충재의 동적특성에 영향을 미치는 요인 분석 (Analysis of Influence Factors on Dynamic Properties of Floor Impact Noise Insulation Materials)

  • 김흥식;주시웅;김대준;김병진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.946-949
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    • 2005
  • In this paper, influence factors on dynamic properties of floor impact noise insulation materials are suggested. For this purpose measurements on the dynamic stiffness and the loss factor of resilient materials are carried out by Korea standard (KS F 2868) according to the change of density, thickness, design pattern, and composition of materials. As a result the values of dynamic stiffness was decreased at high density and thick thickness, and that of loss factor was increased at low density. For dynamic properties, the pattern of lattice and waffle type material is better than that of plat type, and the mixed composition of materials is better than the composition of double layer materials at same thickness.

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