• 한국공간구조학회논문집
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• 제16권2호
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• pp.55-60
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• 2016

The Membrane structure has a number of problems in the application of a fireproof code based on general buildings codes. Thus, the fireproof code of membrane structure is necessary to activate the construction of the membrane structure. Because it requires a systematic classification of fire retardant and flame proof performance of membrane material. Fire retardant and flame proof tests are conducted on membrane materials mostly used in current construction to propose the fire and flame retardant performance criteria of membrane materials. Fire and flame retardant tests results, PTFE membrane material with the glass fiber fabric have a limit-combustible performance. PVDF membrane material with the polyester fabric does not ensure the fire retardant performance, but this membrane material has the flame retardant performance of a thick fabric. Also, ETFE does not ensure the fire retardant performance, but this membrane material has the flame retardant of a thin fabric.

• Korean Chemical Engineering Research
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• 제60권2호
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• pp.267-276
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• 2022

Modelling the energy release performance of energetic material combustion in closed systems is of fundamental importance for aerospace and defense application. In particular, to compensate for the disadvantage of the combustion of single energetic material and maximize the benefits, a method of combusting the mixed energetic materials is used. However, since complicated heat transfer occurs when the energetic material is combusted, it is difficult to theoretically predict the combustion performance. Here, we suggest a theoretical model to estimate the energy release performance of mixed energetic material based on the model for the combustion performance of single energetic material. To confirm the effect of parameters on the model, and to gain insights into the combustion characteristics of the energetic material, we studied parameter analysis on the reaction temperature and the characteristic time scales of energy generation and loss. To validate the model, model predictions for mixed energetic materials are compared to experimental results depending on the amount and type of energetic material. The comparison showed little difference in maximum pressure and the reliability of the model was validated. Finally, we hope that the suggested model can predict the energy release performance of single or mixed energetic material for various types of materials, as well as the energetic materials used for validation.

• 한국재료학회지
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• 제25권3호
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• pp.132-137
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• 2015

The effects of the mixing of an active material and a conductive additive on the electrochemical performance of an electric double layer capacitor (EDLC) electrode were investigated. Coin-type EDLC cells with an organic electrolyte were fabricated using the electrode samples with different ball-milling times for the mixing of an active material and a conductive additive. The ball-milling time had a strong influence on the electrochemical performance of the EDLC electrode. The homogeneous mixing of the active material and the conductive additive by ball-milling was very important to obtain an efficient EDLC electrode. However, an EDLC electrode with an excessive ball-milling time displayed low electrical conductivity due to the characteristic change of a conductive additive, leading to poor electrochemical performance. The mixing of an active material and a conductive additive played a crucial role in determining the electrochemical performance of EDLC electrode. The optimal ball-milling time contributed to a homogeneous mixing of an active material and a conductive additive, leading to good electrochemical performance of the EDLC electrode.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.821-824
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• 2008

This paper presents a systematic approach for estimating material performance of concrete mixture design based on satisfaction curves developed from statistical evaluation of existing or newly obtained material property related data. In performance based material design (PBMD) method, concrete material used for construction of a structure is designed considering a structure's specified performance requirements based on its usage and characteristics such as environmental conditions, structure types, expected design life, etc.Satisfaction curves express the probabilities that one component of substrates (i.e., aggregate size, cement content, etc) of concrete mixture will sustain different criterion value for a given concrete mixture design. This study presents a statistical analysis method for setting up concrete material parameter versus concrete criterion relationships in the form of satisfaction curves and for estimating confidence bounds on these satisfaction curves. This paper also presents an analysis method to combine multiple satisfaction curves to form one unique satisfaction curve that can relate the performance of concrete to a single evaluating value. Based on several evaluated mixture design examples for various material properties, the validity of the proposed method is discussed in detail.

• 한국신뢰성학회지:신뢰성응용연구
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• 제6권4호
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• pp.275-284
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• 2006

A test method for assessing service life of building materials and components based on performance degradation data is developed. The performance of a building material degrades as time goes by and the failure of the material is often defined as the point at which the performance of the material reaches a pre-specified degraded level. A performance-based test method is developed and a numerical example is provided to illustrate the use of the developed test method.

• 한국소음진동공학회논문집
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• 제23권10호
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• pp.920-927
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• 2013

The requirement of acoustic performance about underwater acoustic material which is used in underwater environment more increases. Underwater acoustic material was made by viscoelastic material such as a rubber and a polyurethane etc. In order to increase an acoustic performance, several kinds of inclusions were added to viscoelastic material. In this paper, acoustic modelling and analysis techniques were introduced and the acoustic characteristics of underwater acoustic material were studied. Echo reduction and transmission loss were calculated with volume fraction of inclusion in the material. Also the characteristic impedance and the input impedance of underwater acoustic material were obtained and effects on the echo reduction and transmission loss of material were discussed.

• 한국지진공학회논문집
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• 제17권3호
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• pp.107-115
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• 2013

The purpose of this study was to investigate the performance of hollow reinforced concrete bridge column sections with reinforcement details for material quantity reduction. The proposed reinforcement details has have economic feasibility and rationality and makes construction periods shorter. A model of column sections with reinforcement details for material quantity reduction was tested under quasistatic monotonic loading. As a result, the proposed reinforcement details for material quantity reduction was were equal to existing reinforcement details in terms of the required performance. In the a subsequent paper, the an experimental and analytical study will be performed for the performance assessment of hollow reinforced concrete bridge column sections with reinforcement details for material quantity reduction will be performed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.622-624
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• 2008

This investigation studies the effects of material properties and corresponding propagation wave types on optimal configurations of sound absorbing porous materials in maximizing the absorption performance by topology optimization. The acoustic behavior of porous materials is characterized by their material properties which determine motions of the frame and the air. When the frame has a motion, two types of compressional wave propagate in the porous material. Because each wave in the material make different influence on the absorption performance, it is important to understand the relative contribution of each wave to the sound absorption. The relative contribution of the propagating waves in a porous material is determined by the material properties, therefore, an optimal configuration of a porous material to maximize the absorption performance is apparently affected by the material properties. In fact, virtually different optimal configurations were obtained for absorption coefficient maximization when the topology optimization method developed by the authors was applied to porous materials having different material properties. In this investigation, some preliminary results to explain the findings are presented. Although several factors should be considered, the present investigation is focused on the effects of the material properties and corresponding propagation waves on the optimized configurations.

• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.91-96
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• 2022

The performance and reliability of foreign servomotors and domestic servomotors for manufacturing robots were compared and verified. The mass productivity was confirmed by satisfying the requirements of the demanding companies. The servomotor was designed in consideration of mass productivity while satisfying the requirements of the demanding company. It was mounted on a real robot to check its performance and reliability. To secure mass-production performance, we designed and manufactured easy-to-manufacture parts and jigs to manufacture servomotors and achieved the goal of the mass-production evaluation of servomotors through individual performance evaluation, robot mounting test evaluation, and supplementation.

• 한국조경학회지
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• 제40권5호
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• pp.33-42
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• 2012

본 연구는 자연형 경관석 GFRC를 대상으로 성능기준을 설정하기 위해 국내 외 성능관련 문헌 및 사례 등의 고찰을 통해 요구성능인 재료성능, 구조안전성능, 내구성능, 경관성능의 항목을 40인의 전문가 설문을 통해 선정하였고, 검증된 항목 및 성능기준을 제안하였다. 전문가 설문을 통해 요구 성능 중 재료성능(유리섬유 함유율, 기건비중), 구조안전성능(휨강도, 압축강도) 그리고 내구성능(균열, 내부식성), 경관성능(질감, 백화)을 각각 선정하였다. 기준이 존재하는 재료성능과 구조안전성능의 경우, 시험을 거쳐 기존 기준사례와 비교하여 최종 성능평가기준을 제시하였으며, 기준이 존재하지 않은 내구성능과 경관성능은 기 시공된 인공폭포 등의 경관조형물을 대상으로 현지조사를 통해 직접 측정하여 검증하였다. 본 연구에서는 재료성능, 구조안전성능, 내구성능, 경관성능 등 자연형 경관석 GFRC의 재료 및 시공 후 평가 가능한 항목에 대한 성능기준을 제안하였으나, 추후 시공사례지에 대한 지속적인 모니터링을 통해 최근에 대두되고 있는 친환경적이고, 생태적인 성능기준에 관한 후속 연구가 필요하다.