• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.830-834
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• 2008

Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS (Styrofoam), recycled urethane types, EVA (Ethylene Vinylacetate) foam rubber, foam PE (Polyethylene), glass fiber & rock wool, recycled tire, foam polypropylene, compressed polyester, and other synthetic materials. In this study, we tested floor impact sound reduction characteristic to a lot of kinds of resilient material. The result of test showed that the amount of the Light-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. As the decreasing dynamic stiffness of resilient material, the impact sound reduction amount is increased, especially in the low frequency domain.

• 한국소음진동공학회논문집
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• 제18권2호
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• pp.247-254
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• 2008

Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS(styrofoam), recycled urethane types, EVA(ethylene vinylacetate) foam rubber, foam PE(polyethylene). glass fiber & rock wool, recycled tire, foam polypropylene. compressed polyester, and other synthetic materials. In this study, we tested dynamic stiffness of resilient material and floor impact sound reduction characteristic to a lot of kinds of resilient materials. It was found that dynamic stiffness of multi-layered damping material could be estimated if know value of each layer that compose whole structure. And the test showed that the amount of the heavy-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. The dynamic stiffness looked like between other resilient materials, a similar to the amount of the heavy-weight impact sound reduction was shown.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1145-1148
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• 2007

Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS (Styrofoam), recycled urethane types, EVA (Ethylene Vinylacetate) foam rubber, foam PE (Polyethylene), glass fiber & rock wool, recycled tire, foam polypropylene, compressed polyester, and other synthetic materials. In this study, we tested floor impact sound reduction characteristic to a lot of kinds of resilient material. The result of test showed that the amount of the heavy-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. The dynamic stiffness looked like between other resilient materials, a similar to the amount of the heavy-weight impact sound reduction was shown.

• The Journal of Advanced Prosthodontics
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• 제3권3호
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• pp.140-144
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• 2011

PURPOSE. Finite element study on the effect of abutment length and material on implant bone interface against dynamic loading. MATERIALS AND METHODS. Two dimensional finite element models of cylinderical implant, abutments and bone made by titanium or polyoxymethylene were simulated with the aid of Marc/Mentat software. Each model represented bone, implant and titanium or polyoxymethylene abutment. Model 1: Implant with 3 mm titanium abutment, Model 2: Implant with 2 mm polyoxymethylene resilient material abutment, Model 3: Implant with 3 mm polyoxymethylene resilient material abutment and Model 4: Implant with 4 mm polyoxymethylene resilient material abutment. A vertical load of 11 N was applied with a frequency of 2 cycles/sec. The stress distribution pattern and displacement at the junction of cortical bone and implant was recorded. RESULTS. When Model 2, 3 and 4 are compared with Model 1, they showed narrowing of stress distribution pattern in the cortical bone as the height of the polyoxymethylene resilient material abutment increases. Model 2, 3 and 4 showed slightly less but similar displacement when compared to Model 1. CONCLUSION. Within the limitation of this study, we conclude that introduction of different height resilient material abutment with different heights i.e. 2 mm, 3 mm and 4 mm polyoxymethylene, does not bring about significant change in stress distribution pattern and displacement as compared to 3 mm Ti abutment. Clinically, with the application of resilient material abutment there is no significant change in stress distribution around implant-bone interface.

• 한국소음진동공학회논문집
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• 제18권8호
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• pp.886-895
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• 2008

Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material have a close relation with the floor impact sound reduction. In this study, to examine the relationship between dynamic stiffness and lightweight impact sound level, the dynamic stiffness and floor impact sound level of 51 resilient materials were measured. The impact sound level of each of these resilient materials, whose dynamic stiffness was measured, was measured before and after installation, and the level difference (${\Delta}L$) was analyzed. The result of test showed that the dynamic stiffness of resilient materials decreased, the lightweight impact sound level also decreased, and there was a correlation between the dynamic stiffness and the lightweight impact sound, especially in the low frequency domain.

• 한국도로학회논문집
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• 제15권5호
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• pp.57-64
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• 2013

PURPOSES : It is to evaluate lightweight soil as a subgrade material based on mechanical tests and calculation of pavement performance. METHODS : In this research, various contents of cement and air foam are used to make lightweight soil using wasted dredged soil. Uniaxial compressive strength test is conducted to evaluate strength of 7 and 28 day cured specimens. Secant modulus was calculated based on the stress and strain relationship of uniaxial compressive strength test. Resilient modulus test was measured using by repeated triaxial compression test. The measured resilient modulus was used in layered elastic program to predict fatigue and rutting life at a given pavement structure. RESULTS : Uniaxial compressive strength increases as cement content increases but decrease as air foam content increases. Resilient modulus also increases as cement content increases and decrease as air foam content decrease. CONCLUSIONS : It is concluded that dredge clay soil can be used as subgrade layer material using by lightweight treated soil method.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1994년도 가을 학술발표회 논문집
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• pp.259-264
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• 1994

The 1986 AASHTO Guide for the Design of Pavement Structures introduced the resilient modulus as a definitive material property to characterize roadbed soil. Although the incorporation of resilient modulus represents a significant acvance in pavement design practice, the test procedure for resilient modulus is complicated and time-consuming. Therefore, it is necessary to develop data base of resilient modulus for the soils frequently encountered; and to develop the reliable correlations between resilient properties and parameters from simple routine tests, In this study, resilient modulus tests were performed on five cohesive soils sampled from in-service subgrades. The stress at 1 percent axial strain in unconfined compression test(su1.0%) was found as a good indicator of the resilient modulus, and unique relationship between Mg and Su1.0% was obtained. A simple chart to estimate the resilient modulus at different levels of confining stress and deviator stress was also developed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1042-1049
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• 2007

Recently, a theoretically-sound design approach, using an elastic multilayer model, is attempted in trackbed designs for the construction of high speed railways and new lines of conventional railways. In the elastic multilayer model, the stress-dependent resilient modulus($E_R$) is an important input parameter, that is, reflects substructure performance under repeated traffic loading. However, the evaluation method for resilient modulus using repeated loading triaxial test is not fully developed for practical purpose, because of costly equipment and the significantly fluctuated values depending on the testing equipment and laboratory personnel. In this study, the paper will present an indirect method to estimate the resilient modulus using dynamic properties. The resilient modulus of crushed stone, which is the typical material of sub-ballast, was calculated with the measured dynamic properties and the range of stress level of the sub-ballast, and approximated with the power model combined with bulk and deviatoric stresses. The resilient modulus of coarse grained material decreases with increasing deviatoric stress at a confining pressure, and increases with increasing bulk stress. Sandy soil(SM classified from Unified Soil Classification System) of subgrade was also evaluated and best fitted with the power model of deviatoric stress only.

• 대한토목학회논문집
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• 제14권4호
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• pp.827-838
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• 1994

많은 포장구조 거동 모델은 입상재료의 거동을 묘사하는 구성방정식에 의존하고 있다. 본 연구에서는 비행장 포장의 입상재료 기층의 거동 예측을 위하여, 체적응력(bulk stress)과 팔면체 전단응력(octahedral shear stress)의 함수로 표시된 구성모델이 제안되었다. 이 모델의 특징은 비선형거동을 정확히 예측할 수 있고, 모델상수를 간단히 구할 수 있으며 전단효과에 의한 회복탄성계수의 감소현상을 나타낼 수 있다. 실내시험을 통하여 입상재료의 비선행 회복탄성거동을 관찰하였으며, 제안된 모델을 입증하기 위해 회복탄성계수를 측정하였다. 체적응력과 축차응력이 회복탄성계수의 변화에 가장 주요한 변수임이 관찰되었으며, 실내시험 결과 제안된 모델식에 의한 회복탄성계수의 예측치가 실측치와 잘 일치함을 알 수 있었다. 따라서 제안된 모델식은 비행장 포장에서 일어날 수 있는 광범위한 응력조건하의 입상재료의 회복탄성거동을 잘 묘사할 수 있음을 알 수 있다.

• 대한치과보철학회지
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• 제45권5호
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• pp.621-632
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• 2007

Statement of problem: The failure of adhesion between the resilient denture liner and the denture base is a serious problem in clinic. Purpose: The purpose of this study was to evaluate the effect of denture base resin surface pretreatments (mechanical and/or chemical) on the tensile bond strength between a resilient liner and processed denture resin. Material and method. Acrylic-based resilient liners (Soft liner; GC co., Japan & Coe-Soft; GC America Inc. USA) and silicone-based resilient liners (Mucosoft, Parkell Inc., USA & Dentusil; Bosworth co., USA) were used. Specimens in each soft lining material were divided two groups with or without mechanical pretreatment. Each denture base specimen received 1 of 4 chemical pretreatments including: (1) no treatment, (2) 30-s acetone treatment, (3) 15-s methylene chloride treatment, (4) 180-s methyl methacrylate treatment. All specimens were thermocycled and placed under tension until failure in a universal testing machine. Results: 1. Silicone-based resilient liners exhibited significantly higher tensile bond strengths than acrylic-based resilient liners (P<.05). 2. Grinding the denture base resin improved tensile bond strengths of silicone-based resilient liners, but reduced tensile bond strengths of acrylic-based resilient liners (P<.05). 3. In acrylic-based resilient liners, treating with acetone significantly increased the bond strength of Soft liner and treating with methyl methacrylate significantly increased the bond strength of Coe-Soft (P<.05). However they were not effective compared to silicone-based resilient liner. 4. In silicone-based resilient liners, treating with all chemical etchants significantly increased the bond strength of Mucosoft to denture base, and treating with methylene chloride and methyl methacrylate increased the bond strength of Dentusil to denture base (P<.05). Conclusion: Although chemical and mechanical pretreatments were not effective on tensile bond strength of acrylic-based resilent liner to denture base, treating the denture base resin surface with appropriate chemical etchants after mechanical pretreatment significantly increased the tensile bond strength of silicone-based resilient liner to denture base.