Separately from a single body, crash box is maufactured into the two alumnae by bonding adhesive. Crashbox has the property to absorb the shock by impact transferred to the car body at the collision between cars. In this study, the structural effect and performance are investigated according to the positions of holes punched at this crash box. The optimal structure is investigated for optimal design data of aluminum crash box. The equivalent stresses of study models distributed by compressive loads are compared with each other by using the analysis program of ANSYS. Total energies and mechanical strengths of study models at the real situation are also analyzed. As analysis results, the maximum equivalent stresses of 40880MPa, 42368MPa, 43176MPa, 44960MPa and 43476MPa are shown at study models due to the hole positions of 10mm, 15mm, 20mm, 25mm and 30mm from the upper plane of crash box respectively. Also, the total energy on analysis are verified within the error range of 10 % by comparing that on experiment at the hole position of 10mm. It is thought that the crash box due to the hole position from the upper plane of crash box can be effectively designed through this study result.

In the companion papers (I, II), site-specific response analyses were performed at more than 300 domestic sites and a new site classification system and design response spectra (DRS) were proposed using the results of the site-specific response analyses. In this paper, the proposed site classification system and the design response spectra are compared with those in other seismic codes and verified by different methods. Firstly, the design response spectra are compared with the design response spectra in Eurocode 8, KBC 2016 and MOCT 1997 to estimate quantitative differences and general trends. Secondly, site-specific response analyses are carried out using VS-profiles obtained using field seismic tests and the results are compared with the proposed DRS in order to reduce the uncertainty in using the SPT-N value in site-specific response analyses in the companion paper (I). In addition, site coefficients from real earthquake records measured in Korean peninsula are used to compare with the proposed site coefficients. Finally, dynamic centrifuge tests are also performed to simulate the representative Korean site conditions, such as shallow depth to bedrock and short-period amplification characteristics. The overall results showed that the proposed site classification system and design response spectra reasonably represented the site amplification characteristic of shallow bedrock condition in Korea.

부가적인 제어장치를 사용하여 구조물 감쇠를 증가시키는 것은 건축물의 풍응답을 제어하기 위해 자주 사용되는 방법 중 하나이다. 본 연구의 목적은 TMD와 AMD의 다중모드응답 제어성능을 비교하는 것이다. 실제 AMD가 설치된 39층 건물을 사용하였으며, 이전 연구에서 시스템식별을 통해 얻어진 모드정보에 따라 수정된 수치해석모델을 사용하였다. AMD 제어력은 속도피드백, 뱅뱅 제어, LQR 알고리즘을 사용하여 결정하였다. 1차 모드의 RMS 응답을 유사한 수준으로 맞추는 조건에서 TMD와 AMD의 고차모드제 어성능을 비교하였다. 그 결과 TMD는 단일 모드에 대해서만 응답을 저감시킬 수 있었으나, AMD는 다중모드 제어가 가능함을 확인하였다.

본 연구는 비고전 감쇠를 가지는 구조물, 모드가 매우 인접되어 있는 구조물의 모드를 분리하기 위하여 제안된 최적화 상태 공간 모드분리법의 검증을 목적으로 하고 있다. 실구조물에 대한 모드분리의 가능성 및 적용성을 위하여 40층 규모의 건물에 동조질 량감쇠기가 설치된 시스템을 대상으로 하였으며 그로부터 계측된 응답에 모드분리법을 적용하였다. 모드분리 결과를 보면, 해당 모드 에서의 에너지 집중을 목적함수로 설정한 경우에는 이웃한 인접모드의 고유진동수 부근에서 파워스펙트럼 값을 인위적으로 작게하여 왜곡하는 경향이 나타나는 것을 확인할 수 있었다. 이러한 왜곡현상을 방지하기 위해 도입된 구속조건과 이를 이용한 목적함수의 설 정을 통해서 인접한 모드가 효과적으로 분리 가능함을 확인 할 수 있었다.

본 논문에서는 MRV 규제 대응을 위해 선박 운항효율데이터 수집 및 검증 시스템을 구축하고 이를 활용하여 해운선사 업무 지원과 국가 온실가스 인벤토리 산정이 가능한 국제해운 에너지효율 포탈 시스템을 설계하였다. 시스템 요구조건을 도출하기 위하여 EU MRV 법안과 IMO MRV 논의사항, 해운선사의 선박에너지효율과 온실가스규제 대응 및 국제해운 온실가스 통계 현황에 대하여 분석 하고 선박 에너지효율과 온실가스 배출량 데이터 수집을 위하여 선내 장비, 에너지효율 측정 장비, 운항보고서를 활용한 데이터 수집 모듈과 선박에서 수집된 데이터를 육상으로 전송하기 위해 관리가 용이하고 사용량이 최소화된 데이터베이스기반 전송 모듈을 설계하 였다. 수집된 데이터의 표준보고양식 변환, 모니터링, 통계 및 분석, 검증, 보고서 자동생성과 국가 온실가스 인벤토리 지원이 가능한 국제해운 에너지 포탈시스템을 설계하였다.

The simulation analysis about the mechanical behavior by thickness on the compression procedure of the bonded aluminum foam is carried out in this paper. The maximum equivalent stress is increased very rapidly at three models. This stress approaches the yielding point when the compressive displacement is proceeded as much as 6mm. After yielding point, this stress approaches the maximum point. A value of this stress is about 1.0MPa. The reaction force approaches the maximum point when the compressive displacement is proceeded as much as 6mm. These reaction forces are shown to be 3000N, 5000N, 7100N respectively at the specimen thicknesses of 15, 25 and 25 mm. The maximum deformation energy is abruptly increased from the displacement of 6 mm and the compressive energy in case of the specimen thickness of 15 mm is shown to highest among three specimens when the displacement is proceeded as much as 13 mm. The experiment with the case of specimen thickness of 25mm is carried out in order to verify these analysis results. The mechanical properties of the bonded structures composed of aluminum foams can be thought to be analyzed effectively.

The purpose of this study was to measure concentrations of K+, Na+, Cl－ by ionometer with check salt strip, simple salimeter and Ion-selective electrode (ISE) and compare the results of each mensuration; furthermore, the possibility of inferring the Na+ concentration from Cl－ concentration of urine and the impact of K+ on the concentration of each ion was examined. The results showed that ISE determined Na+ and Cl－ concentrations in the urine are highly interrelated (R=0.9039); in addition, concentrations of Cl－, measured with strip and ISE from urine are highly interrelated (R=0.9338). The concentration of Na+ in urine, inferred by measuring Cl－ concentration with strip, has a high relationship (R=0.8580) with the concentration of Na+ in urine, measured by ISE. The results of our study will increase awareness of Na+ intake and the utility of check salt strip, as well as the possibility of inferred Na+ concentration from measures of Cl－ concentration as a screening test for reducing sodium intake.

Permanent deformation plays a key role in performance based earthquake resistant design. In order to estimate permanent deformation after earthquake, it is essential to secure reliable response history analysis(RHA) as well as earthquake scenario. This study focuses on permanent deformation of an inverted T-type wall under earthquake. The study is composed of two separate parts. The first one is on the verification of RHA and the second one is on an effect of input earthquake motion. The former is discussed in this paper and the latter in the companion paper. The verification is conducted via geotechnical dynamic centrifuge test in prototype scale. Response of wall stem, ground motions behind the wall obtained from RHA matched pretty well with physical test performed under centrifugal acceleration of 50g. The rigorously verified RHA is used for parametric study to investigate an effect of input earthquake motion selection in the companion paper.

PURPOSES: This study aimed to evaluate the appropriateness of safety with the standard for threshold zone luminance as specified in the Recommendation for Lighting of Traffic Tunnel, which has been widely adopted worldwide. METHODS: A driving test of the subject in a full-scale road tunnel was conducted. The adaptation luminance and threshold zone luminance, which should be known for the driver to perceive an object within stopping sight distance, were obtained. These values were compared with the adaptation luminance and threshold zone luminance obtained by the existing reduced model test and tunnel lighting standard that has served as a guideline for the current threshold zone luminance standard. RESULTS : According to this study, threshold zone luminance should be increased to at least 1.8 times the value proposed in the existing studies and to twice the domestic tunnel lighting standard (KS C 3703: 2014). CONCLUSIONS : The threshold zone luminance proposed in this study differs largely from that obtained from indoor tests and from the current tunnel lighting standard used worldwide; this difference may be attributed to the fact that the indoor tests did not incorporate driving workload, non-uniformity of luminance distribution in terms of sight, and factors that reduce the visibility of the driver, such as the light reflected into the driver’s eyes. Hence, it is necessary to further review the factors that reduce the visibility of drivers approaching tunnels in order to determine the rational tunnel threshold zone luminance.

This study investigates the mechanical behavior at the compression of bonded aluminum foam. Four kinds of specimen thicknesses are 25, 50, 75 and 100mm. These aluminum foams are compressed with the speed of 5mm/min. The reaction forces in cases of 25, 50, 75 and 100mm are 2510, 5080, 7700 and 10400N respectively. The equivalent stresses are 0.96, 1.00, 1.02 and 1.03MPa respectively. These analysis results are verified by comparing with the experimental results. The results of this study can be contributed to the safe design of structure.

As a part of light weight, the adhesive has been applied to joint the mechanical structure. The porous material is used with aluminum foam in case of the structure bonded with only adhesive. In order to confirm the durability, it is necessary to investigate the fracture toughness at the bonded joint. So, the fracture property at joint interface of aluminum foam different from the non-porous material becomes especially important. In this study, the static facture analysis was carried out with DCB specimen bonded with adhesive as the loading type of mode Ⅲ. The thicknesses of specimens are 35, 45 and 55 mm. When the forced displacements 5 mm applied on the specimen proceed at specimen thicknesses of 35, 45 and 55 mm, the maximum stresses is shown to be happened at the range from 3.3 MPa to 3.6 MPa. The maximum equivalent stress happened at the specimen thickness of 35mm becomes highest among four kinds of specimens. The static experiment is carried on in order to verify these analyses representatively. As the experimental data become similar with the simulation data, it is thought that these analysis data can be applied at analyzing them into the adhesive joint of real porous material.

PURPOSES: Implementation and verification of the simple linear cohesive viscoelastic contact model that can be used to simulate dynamic behavior of sticky aggregates. METHODS: The differential equations were derived and the initial conditions were determined to simulate a free falling ball with a sticky surface from a ground. To describe this behavior, a combination of linear contact model and a cohesive contact model was used. The general solution for the differential equation was used to verify the implemented linear cohesive viscoelastic API model in the DEM. Sensitivity analysis was also performed using the derived analytical solutions for several combinations of damping coefficients and cohesive coefficients. RESULTS : The numerical solution obtained using the DEM showed good agreement with the analytical solution for two extreme conditions. It was observed that the linear cohesive model can be successfully implemented with a linear spring in the DEM API for dynamic analysis of the aggregates. CONCLUSIONS: It can be concluded that the derived closed form solutions are applicable for the analysis of the rebounding behavior of sticky particles, and for verification of the implemented API model in the DEM. The assumption of underdamped condition for the viscous behavior of the particles seems to be reasonable. Several factors have to be additionally identified in order to develop an enhanced contact model for an asphalt mixture.

As a part of light weight, the adhesive has been applied to joint the mechanical structure. The porous material is used with aluminum foam in case of the structure bonded with only adhesive. In order to confirm the durability, it is necessary to investigate the fracture toughness at the bonded joint. So, the fracture property at joint interface of aluminum foam different from the non-porous material becomes especially important. In this study, the static facture analysis was carried out with DCB specimen bonded with adhesive as the loading type of mode Ⅲ. The thicknesses of specimens are 35, 45 and 55 mm. When the forced displacements 5 mm applied on the specimen proceed at specimen thicknesses of 35, 45 and 55 mm, the maximum stresses is shown to be happened at the range from 3.3 MPa to 3.6 MPa. The maximum equivalent stress happened at the specimen thickness of 35mm becomes highest among four kinds of specimens. The static experiment is carried on in order to verify these analyses representatively. As the experimental data become similar with the simulation data, it is thought that these analysis data can be applied at analyzing them into the adhesive joint of real porous material.

As aluminum foam has the most superior absorption of impact energy, this material has been used at automobile and airplane. If aluminum foam is used by jointing bolt and nut, it can be broken. Therefore, it is more effective to bond aluminum foam and other materials by adhesive. In this study, the fatigue fracture simulation through ANSYS program is carried out on the aluminum foam specimen bonded with adhesive as the type of DCB Mode Ⅲ. There are four kinds of specimens with the types of DCB Mode Ⅲ in this study. The thicknesses of four specimens are 35mm, 45mm, 55mm and 65mm. In cases of specimen thicknesses of 35mm, 45mm, 55mm and 65mm, the maximum loads are shown as ±0.2kN, ±0.55kN, ±1kN and ±1.2kN respectively. As the specimen thickness increases, the maximum loads increase. The results of fatigue experiment as specimen thickness of 55mm can be shown to approach the simulation results by confirming the simulation results of this study. So, The simulation data can be applied in order to investigate the mechanical property at DCB specimen with the type of Mode Ⅲ.

The purpose of this study was to investigate the performance of new hollow reinforced concrete (RC) bridge pier sections with triangular reinforcement details. The proposed triangular reinforcement details are economically feasible and rational and facilitate shorter construction periods. A model of pier sections with triangular reinforcement details was tested under quasi-static monotonic loading. As a result, proposed triangular reinforcement details was equal to existing reinforcement details in terms of required performance. In the companion paper, the parametric study for the performance assessment of new hollow RC bridge pier sections with triangular reinforcement details is performed.

We have conducted a verification test of correlation between bird community indices and bird sound recording results in order to use the equipment which deals with the automatic sound collecting system, the song meter. The study areas include four sites which are Gombaeryoung and Zochimryoung in Jeombongsan Mountain and Jookryoung and Gochiryoung in Sobaeksan National Park. We collected the bird sound data five times using a sound recorder and field survey results in the same place of the study site. As a result of the sound recording from the field survey, the species recorded by three researchers of sound analyst include common resident species or species which have a relatively conspicuous call and song. On the contrary, the species recorded by only one researcher are a relatively rare or inconspicuous species or was familiar with the personal experiences of each researcher. The number of species recorded by only one researcher totaled fourteen species (36.8 %), and that of two researchers totaled twelve species (31.6 %), and that of three researchers totaled twelve species (31.6 %). The correlations of the number of species among three researchers was not significant in some results, but the sum or maximum count of the number of species was useful to estimate a significant correlation between the result of researchers and the indices of field surveys. As a result of correlation analysis by using sound recordings, the maximum number of species among the three researchers significantly correlated with the number of species, the species diversity index and the species abundance index in the field survey at the same site, however it did not correlate with the number of individuals and species evenness index. As a result of sound analysis collected from the stationary sound recording system; song meter, the number of frequencies in bird songs and calls correlated with the number of species in the field survey at the same site. The number of calls and songs decreased as time went by. Finally, we could test the active time range and change the activity strength by using a sound recording system. In particular, that sound recording system is able to collect data in same time and site, so it is expected so that the equipment not only replenish a shortage of researchers and survey periods in field research in a short term monitoring survey, but also be able to acquire statistical objectivity.

CFRP composites have high specific strength, specific stiffness, long fatigue life, light weight environmental safety characteristics. In this study, the mechanical properties are investigated through the compressive simulation analysis on the carbon fiber reinforced plastic sandwich. The experiment is carried out with the same condition as the analysis to verify the analysis result. One sandwich plate is composed with four layers. From the upper, this plate has the first, second, third and fourth layers due to the arrangement of angle direction. A plate has the symbol of [0/30/30/0] as the first, second, third and fourth layers due to the angle directions of 0°, 30°, 30° and 0°. There are the plates of [0/30/30/0], [0/60/60/0] and [0/90/90/0] in this study. The maximum compressive load becomes 53.139kN during the compression time of 12 sec in case of the plate of [0/30/30/0]. The maximum compressive load becomes 61.826kN during the compression time of 12 sec in case of the plate of [0/60/60/0]. The maximum compressive load becomes 53.002kN during the compression time of 12 sec in case of the plate of [0/90/90/0]. So, the plate of [0/60/60/0] endures the most load among three plates. The result of this study can be applied practically through the validation of experimental data on the simulation data. In this study, the mechanical characteristics are examined systematically through the impact analysis on the composite material of the carbon fiber reinforced plastic with aluminum foam by using the impact absorption due to CFRP plate.