Transition piece of offshore wind turbine tower is one of the main parts which takes the direct load and pass on to the lower support structure. In this study, a new design method for the transition piece has been developed. The trasition piece was designed based on the the load flow which was analyzed by approximation and was evaluated by FEM.

It is necessary to develop the damage function to cope with the increasing damage of steel transmission towers. A simplify analysis to evaluate the performance resistance capacity, which is essential for the development of the damage function, was performed. The 154kv power transmission towers installed between Sokcho and Yangyang were selected as the target structures. Wind loads were calculated and applied to the target structures according to the domestic transmission and distribution facility design standards. As a result of this study, displacement according to wind speed of the target structure was derived.

This study examined the effects of the embedded auxetic grating structures by design on numerical analysis. Compressive tests were performed and the results showed the effectiveness of auxetic grating structures for the enhancements of stiffness.

When reinforcing an existing reinforced concrete beam-column building with a precast concrete panel, special connection between the PC member and the RC member is required to solve the time dependent deformation of the RC member and to receive the large shear forces. The aim of this study is to obtain the shear strength of upper connection between the existing RC beam-column and infilled PC wall panels in experimentally and theoretically. Thus, the static shear loading tests were conducted on the 6 specimens with the plate connection. Shear failure was resulted from the weakest portion of interior PC panel, exterior RC, and the connection, when the PC portion which located at the center of specimen was pulled upward from the bottom. The experimental result was compared with analytical result from ACI 318M-14 Chapter 17 for the shear strength of post-installed anchor and PCI Handbook 7th edition 6.8 Structural Steel Corbel (PCI Design Handbook 7th edition, 2010) for the strength of cast-in H-beam. The analytical and experimental results show final failure at the same location. The failure loading of experiment showed larger than average 6% to that of the analysis.

This paper addresses simplified method for nonlinear soil–structure interactions (SSI) analysis of base-isolated nuclear power plant (NPP) structure under incident seismic waves. The accuracy and applicability of the method are evaluated by comparing with nonlinear time history responses obtained by the boundary reaction method (BRM).

In this study, We have evaluated the applicability of the substructuring technique to reducing the computational cost of a three-dimensional analysis of a vehicle-track structure dynamic interaction. When the substructuring technique is applied properly to the three-dimensional dynamic interaction analysis, computational cost can be greatly cut down without loss in accuracy.

This study examined the effects of the embedded auxetic grating structures by design on numerical analysis. Compressive tests were performed and the results showed the effectiveness of auxetic grating structures for the enhancements of stiffness.

When reinforcing an existing reinforced concrete beam-column building with a precast concrete panel, special connection between the PC member and the RC member is required to solve the time dependent deformation of the RC member and to receive the large shear forces. The aim of this study is to obtain the shear strength of upper connection between the existing RC beam-column and infilled PC wall panels in experimentally and theoretically. Thus, the static shear loading tests were conducted on the 6 specimens with the plate connection. Shear failure was resulted from the weakest portion of interior PC panel, exterior RC, and the connection, when the PC portion which located at the center of specimen was pulled upward from the bottom. The experimental result was compared with analytical result from ACI 318M-14 Chapter 17 for the shear strength of post-installed anchor and PCI Handbook 7th edition 6.8 Structural Steel Corbel (PCI Design Handbook 7th edition, 2010) for the strength of cast-in H-beam. The analytical and experimental results show final failure at the same location. The failure loading of experiment showed larger than average 6% to that of the analysis.

This paper addresses simplified method for nonlinear soil–structure interactions (SSI) analysis of base-isolated nuclear power plant (NPP) structure under incident seismic waves. The accuracy and applicability of the method are evaluated by comparing with nonlinear time history responses obtained by the boundary reaction method (BRM).

Anaerobic digestion is one of the most economical ways to treat organic wastes; the production of excessive sludge is limited; aeration is not required; operation cost is low; valuable energy resource (methane) is produced. However, propionate, an intermediate substance during the process, is known to inhibit biochemical process at high concentration; but it is difficult to be degraded biologically as its oxidation is thermodynamically unfavorable (△G>0). However, there are several microorganisms which could oxidize propionate fully by their syntrophic association. Therefore, in this research, the propionate enrichment culture was produced in large amount (~1L), and the main players which are responsible for utilizing propionate are identified. Furthermore, the kinetic parameter was obtained from this research. Seed came from two different full-scale anaerobic digesters which is located in Joongrang (JR) and Sincheon (SC). 16s rRNA gnee based metagenomics results indicated that Smithella propionica and Methanobacterium beijingense were the most dominant species in all seeds. The fact that bacterial family Syntrophomonadaceae and archaeal genus Methanosaeta were also found significantly in all seeds means that there might be symbiotic relationship among propionate oxidizing bacteria, butyrate oxidizing bacteria, hydrogenotrophic methanogens and acetotrophic methanogens in complete oxidation of propionate. Based on the first order kinetic which indicated propionate degrading rate, k (1/day) on JR and SC was represented 0.0243 and 0.0223, respectively. Also, based on Modified-Gompertz model, umax on JR and SC was represented as 0.024 and 0.016, respectively.

This study results the shear capacity of a wall depending on the postion and reinforcement of the equipment opening using finite element analysis. Analysis results show that when the openings are placed in the corner, the shear capacity was reduced than in the center. and reinforcing with a steel sleeve can compensate for the reduced strength

As development of the construction technique, new composite material has been developed and research on structures made of this material is needed recently. In this study, curved composite laminated frame structure with four ply is analyzed using shell elements. There are six angle change cases and maximum vertical displacement with case 2 and 6 which have ±45 degree is smaller than other cases’ displacements.

Between the RC and SC structures, the connection method, such as baseplate type(mechanical splice) & noncontact lap splices, was suggested in KEPIC SNG. In previous research, baseplate type using #14bar were developed and their structural integrity was confirmed by the actual bending test. However, the structural integrity of noncontact lap splices using #14bar has not been yet confirmed through experiment. In this study, load-displacement curve of noncontact lap splices FEM model is compared with baseplate type analytical results. This research suggests the possibility of the noncontact lap splice for connection design in case of #14 dowel bar of RC Structure.

Extended Accumulated SIBIE in order to improve the limit of visibility of Accumulated SIBIE method is a method to significantly improve the performance of measurements by extension the region of visibility to a low-frequency region. Decrease of resonant frequency displayed in the lower frequency region than the thickness frequency is due to reduction in rigidity by essentially degradation and cross-sectional loss of members. It is necessary to clarify the relationship between the resonance frequency and the deterioration or damage patterns to learn these patterns. In this research, by obtaining the vibration mode and the natural frequency by the eigenvalue analysis, it was confirmed that dynamic analysis which take time and effort can be minimized.

본 연구의 주목적은 유역의 유출응집구조를 분석하고 이를 기반으로 멱함수 법칙분포의 대표적 특성인 보편성을 수문학적 관점에서 입증해 보고자 하는 것이다. 이를 위하여 최우법에 따라 집수면적의 누가분포에 대한 멱함수 법칙분포의 적합을 수행하였으며 이로부터 도출된 멱함수 법칙분포의 지 수를 집수평면의 형상을 기반으로 평가하여 보았다. 주요한 결과로서 본 연구의 대상 유역들은 집수평면의 규모에 대하여 거의 모두 동일한 형태의 분 포를 취하고 있음을 확인할 수 있었다. 본 연구에서 얻은 멱함수 법칙분포의 지수는 선행연구에서 제시된 값에 비하여 다소 큰 수치로 나타났는데 이는 본 연구의 대상유역들이 가진 자기상사성의 특징을 반영하는 것으로 판단된다. 향후 DEM을 기반으로 보다 더 실제에 가까운 흐름방향모의를 통한 집 수평면의 멱함수 법칙분포의 보편성에 대한 연구가 반드시 수행되어야 할 것이다.

A new array was suggested for effective leakage detection of concrete water facility. This array was modified to serve the purpose. Plus and minus currents have been installed respectively on the upstream and downstream water in order to detect the flow of water floating through the crack of facility. Potential poles in two lines have been installed closer than current sources to the weir to measure potential difference in upstream and downstream. Interpreting the potential difference data acquired by the new array, we could predict that where is the leakage zone. The possibility that can distinguish the leakage zone has been confirmed by numerical and physical modeling and problem position expected to leak was verified in field exploration.

Waterside structures such as dams or levees are essential for flood protection, and flood induced failures of such structures can cause serious damages. Real-time safety prediction can prevent most of the damages to inland or the consequential economic damages induced by flood hazards. This study introduces a method of real-time safety prediction by evaluating the correlation between numerical simulation, real-time measurement, and geo-centrifuge data.

In this study, an analytical study on the effect of the support structure deflection on the impact test result was carried out to set up the accurate impact test method. Various impact analyses of the CEDM(control element drive mechanisms) impact test were performed using LS-DYNA commercial FE program. Finally, the effect of the boundary condition of the support structure and impact loading duration were investigated.

An ICH RC (internally confined hollow reinforced concrete) tower for supporting 5.0MW wind turbine was developed and its standard sections were designed. It was found that ICH RC wind tower is satisfied with maximum 200% bigger moment which is required for pre-existing steel tower. Also, the results from the FAST showed that 5.0MW turbine can be normally operated with the ICH RC tower.