• Title/Summary/Keyword: Resilient by Design

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Vibration characteristics of diesel generator set with resilient mount and prevention of vibration on the design stage (탄성 마운트 장착 디젤 발전기 세트의 진동 특성과 예방에 대한 연구)

  • Lee, Kun-Hee;Bae, Jong-Gug;Lee, Soo-Mok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.921-924
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    • 2005
  • Diesel generator sets with resilient mounts often experience resonances by major excitations which come from diesel engine and their foundation with rigid body modes. Because their natural frequency is determined by moment of inertia and stiffness of resilient mount vibration problems are resolved by changing location and stiffness of resilient mounts. But the calculated natural frequencies are inaccurate due to uncertainty of the inertia and mount stiffness. So this result can be useless on the design stage. In this paper, the stiffness of mount is evaluated on result from mount stiffness test in laboratory and generator set vibration test and a simple calculation method for moment of inertia is proposed. Based on these data, the procedure to select optimized mount stiffness and location on the design stage is set up.

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Study on the Base and Subbase Method of Agricultural Road -On the Resilient Modulus Characteristics of the Subgrade and Cement Treated Base- (농도의 기층 및 보조기층 공법연구 -노상 및 시멘트 안정 처리층의 Mr 특성을 중심으로-)

  • 도덕현
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.31 no.2
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    • pp.66-81
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    • 1989
  • The characteristics of resilient modulus(Mr) which dominates the life of pavement and the design of pavement were investigated on the test specimens which were cement treated and non-treated of the three different soil types. The results are summarized as follows : 1. The resilient modulus was decreased by increasing the cyclic deviator stress ($\sigma$d) , especially the resilient modulus was gradually decreased or sometimes increased when the value of ad was greater than 0.75- 1. 0kg/cm$^2$. 2. The resilient modulus was increased by increasing the homogeneous confined stress ($\sigma$do) and such phenomena were distinct on the coarse soils. 3. The resilient modulus was increased by increasing the ratio of confined stress(Kc), and this phenomena were eminent on the coarse soils too, and the higher permanent strain was showed by increasing the value of Kc. 4. In the drained cyclic triaxial compression test, the value of ad, Kc, and (Oho) was introduced by the following interrelated equations which were similar to the Mr model of Cole. Kcn/Mr=K1(J$_2$/ $\tau$oct)K2 ............. (coarse soli) Mcn/Mr=K3($\sigma$dp/ $\tau$f)k4 ...............(fine soils) 5. The stress path was not much affected by the value of Mr, however, moisture content, dry desity, and contant of fines affected the value of Mr. 6. In the soil-cement specimens, the resilient compression strain($\varepsilon$d) was decreased by the increment of the $\sigma$ho, and Mr was decreased by increasing the $\sigma$d 7. In the flexible pavement. the cement treated layer should be designed not to fail by the fatigue before the designed traffic load, and actually the pavement could cover the traffic load to a certain extent under the post-crack phase, therefore farther studies on this phenomena' are required in the design analysis. 8. The finite element computer program (ANALYS) was used for displacement analysis of pavement containing the cement-treated layer, The result showed that the program used for this analysis was proved to be usable.

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The effects of engine's misfiring condition on the dynamic behaviour of resilient mounting systems (엔진의 착화실패가 탄성지지계의 동적거동에 미치는 영향)

  • 손석훈;장민오;김성춘;김의간
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.04a
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    • pp.188-193
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    • 1996
  • The purpose of resilient mounting for marine engine is to prevent noise and ship damages caused by engine vibration. Although many researches for the resilient mounting system have been carried out, these results have limit to apply on the marine engine systems. Because marine engine generally have low speed operating range and have to consider misfiring condition. In this paper, we studied the effect of engine's misfiring on the resilient mounting systems. And the influences of design parameters, such as dynamic characteristics and location angles of resilient rubber mountings, were also examined on the single and double resilient mounting systems.

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A Study on Waterfront Planning and Design from the Perspective of Resilience - Focusing on Resilient by Design Challenge and Sponge City (리질리언스 관점에서 수변 공간 계획에 관한 고찰 - 리질리언트 바이 디자인 공모전과 스펀지 시티 프로젝트를 바탕으로)

  • Jinhyun Jun
    • Journal of the Society of Disaster Information
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    • v.19 no.3
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    • pp.562-571
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    • 2023
  • Purpose: This study aims to provide a direction for restructuring resilient waterfront spaces, emphasizing the severity of water-related disasters and the significance of developing responsive urban strategies. Method: To achieve this objective, the study analyzes overseas planning and design cases based on the theoretical framework of urban resilience. The goal is to identify physical and social systemic design elements that can be applied to waterfront space planning and design of Korea. Result: The proposals from the Resilient by Design Callenge included strategies for enhancing social systems and promoting sustainability in a more systematic manner. Additionally, various physical design strategies and technologies were identified in the Sponge City projects, which aim to create a flexible urban waterfront space. Conclusion: When planning and designing Korean waterfront spaces to effectively respond to disasters, several elements should be considered, such as enhancing educational functions, expanding local resident participation, establishing a governance system, developing systematic sustainable plans, adopting ecological approaches, and implementing various low-impact development techniques.

Resilient Modulus of Weathered Granite Soil in the Central Part of Korea (화강암풍화토의 동탄성계수에 관한 연구 -중부지역을 중심으로-)

  • 김주한;이종규
    • Geotechnical Engineering
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    • v.6 no.1
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    • pp.35-42
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    • 1990
  • Over the years, most pavement designs based on soil strength and permanent strain are almost independent of soil elasticity. However, it was found that plasticity and elasticity of soil have both effected on the failure of pavement structures. The elasticity of soil, hence, using the resilient modulus is reflected for recent pavement design. Although the current AASHTO specifications(1986) for pavement design had changed the soil support value to the resilient modulus, triaxial devices conducting the resilient modulus test have not been fully equipped in a great majority of laboratories. Thus, in the present work, such a resilient modulus is usually derived(from CBR, K values, etc.) by estimating equations. The purpose of this study is to evaluate the resilient modulus of weathered granite soils sampled from 4 points of the central region of Korea by means of AASHTO T 274-82. According to this, some empirical equations for predicting that of the weathered granite soil are proposed and then, the relationship to convert CBR into the resilient modulus is developed.

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A Study on Establishing the Subbase Compaction Control Method based on the In-situ Elastic modulus (현장탄성계수에 근거한 보조기층 다짐관리방안 연구)

  • Choi, Jun-Seong;Kim, Jong-Min;Han, Jin-Seok;Kim, Bu-Il
    • International Journal of Highway Engineering
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    • v.13 no.1
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    • pp.33-40
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    • 2011
  • The resilient modulus which is presented mechanical properties of compacted subbase material is the design parameter on the Mechanistic - Empirical pavement design guide. The compaction control method on the Mechanistic - Empirical pavement design guide will be the way to confirm whether the in-situ elastic modulus measured after the compaction meets the resilient modulus which is applied the design. The resilient modulus in this study is calculated by the neural network suggested by Korea Pavement Research Program, and degree of compaction as the existing compaction control test and plate bearing capacity test(PBT) was performed to confirm whether the in-situ elastic modulus is measured. The Light Falling Weight Deflectometer(LFWD) is additionally tested for correlation analysis between each in-situ elastic modulus and resilient modulus, and is proposed correlation equation and test interval which can reduced overall testing cost. Also, the subbase compaction control procedure based on the in-situ elastic modulus is proposed using the in-situ PBT and LFWD test result.

An Experimental Study on the Dynamic Characteristics of Onboard Machinery with Resilient Mounts (선내 탑재 마운팅 장비의 동특성에 관한 실험적 연구)

  • 김극수;최수현
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.2
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    • pp.28-33
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    • 2003
  • This study is performed to evaluate and design the dynamic characteristics of the onboard machinery with resilient mounts. To avoid resonance with onboard machinery and external force, it is necessary to calculate natural frequencies of the resilient mounting system more accurately. Natural frequencies of on board machinery are determined by rigid body properties(mass, moment of inertia, center of mass) of machinery and stiffness of mounts. But it is very difficult to calculate rigid body properties theoretically. And stiffness properties of rubber mounts vary with dynamic displacement, pre load, frequency and temperature, and so on. In this study, we have identified rigid body properties using experimental modal analysis and estimated dynamic stiffness of rubber mount for onboard machinery using measured vibration response during seatrial. We measured displacement excitation through deck under mounts and evaluated relationship between modes of resilient mounting system and main excitation sources of a ship.

Optimal Design for Resilient-Mounted Structures Using Structural Synthesis Method (구조합성법을 이용한 탄성마운트지지 구조물의 최적설계)

  • Lee, Seung-Young;Moon, Seok-Jun;Kim, Byung-Hyun;Lee, Sang-Gab
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.182-186
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    • 2006
  • An efficient dynamic response analysis mettled of structures supported by resilient mounts is presented by using the structural synthesis method in frequency domain and time domain. As a numerical example, a mount-deck system is considered. Through numerical simulations, the validity of the presented method is verified by comparison of the results with those of the 'traditional' analysis method.

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An Analytical Study of Flexible Pavement Design Using Resilient Modulus Model of Expanded Polystyrene (EPS) (EPS 회복탄성계수 모델을 이용한 연성포장설계의 해석적 연구)

  • Park, Ki-Chul;Chang, Yong-Chai
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.2
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    • pp.35-44
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    • 2015
  • The resilient modulus model of EPS geofoam to be used for a flexible pavement design was developed. In this study, the model was applied to design the flexible pavement and to predict the magnitude of the deformation of EPS geofoam blocks as a subgrade in the flexible pavement structure by using the resilient modulus model of EPS geofoam (RMEG) program. The RMEG program presented how much the EPS geofoam subgrade settled over the designed duration and the AASHTO flexible pavement design equation with the resilient modulus of EPS geofoam noted that how long the flexible pavement endured under traffic loads with 70% reliability for the estimated duration with less than 5mm vertical deformation during 20.6 years without the significant pavement distress as a substitute material for the natural soils.

Effect of Unequal Settlement on Damage of Resilient Sleepers on Concrete Ballast (콘크리트도상 방진침목의 파손에서 부등침하가 미치는 영향)

  • Kim, Jin-Il;Lee, Jee-Ho
    • Journal of the Korean Society of Safety
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    • v.21 no.2 s.74
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    • pp.80-88
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    • 2006
  • In the present study damage behavior of resilient sleepers on concrete ballasts is analyzed. Cracks of resilient sleepers in a railway track system are concentrated on inside of blocks to which the tie bars are connected. Finite element analysis is performed by dividing a block into the straight section and the curved section according to the load condition of the resilient sleeper, and limited the interpretation within the range of resilience. In addition, the value of stress obtained from the interpretation was compared with the allowable stress of concrete to determine the safety. According to the result of numerical analysis, compared with the stress before unequal settlement, the tensile stress of the inside of the block increased significantly after the settlement considering the entire block, and the tensile stress of this part exceeded the allowable stress of concrete, so was undesirable in terms of safety. In reality, the arrangement of tensile stiffeners inside blocks connected to tie bars is improper in the design of resilient sleepers, and when unequal settlement occurs, tensile stress increases on this part and consequently causes cracking damage. It is necessary to arrange wire meshes or tensile reinforcing bars in a structurally safe way to reinforce the inside of blocks on which cracks are concentrated.