Performance-Based Seismic Design (PBSD) is an approach that evaluates how structures will perform under different
levels of seismic activity. It focuses on ensuring that buildings not only withstand earthquakes but also meet specific
performance objectives, such as minimizing damage or maintaining functionality after the event. Unlike traditional methods,
PBSD allows for more tailored, cost-effective designs by considering varying degrees of acceptable damage based on the
structure's importance and use. PBSD was introduced in Korea in 2016 to replace elastic design, which is inevitable to
over-design to cope with all variables such as earthquakes and winds. When PBSD is applied to the structural design new
building, One of the challenges of PBSD is the complexity involved in creating accurate inelastic analysis models. The
process requires significant time and effort to analyze the results, as it involves detailed simulations of how structures will
behave under seismic stress. Additionally, organizing and interpreting the analysis data to meet performance objectives can
be labor-intensive and technically demanding. In order to solve this problem, a post-processor program was developed in
this study. A post-processor was developed based on Excel program using Visual Basic for Applications(VBA). Because
analysis outputs of Perform-3D, that is a commercial software for structural analysis and design, are very complicated,
generation of tables and graphs for report is significant time and effort consuming task. When the developed post-processor
is used to make the seismic design report, the required task time is significantly reduced.
This research introduces a novel probabilistic approach to consider the effects of uncertainty parameters during the design and construction process, providing a fresh perspective on the evaluation of the structural performance of reinforced concrete structures. The study, which categorized various random design and construction process variables into three groups, selected a two-story reinforced concrete frame as a prototype and evaluated it using a nonlinear analytical model. The effects of the uncertainty propagations to seismic responses of the prototype RC frame were probabilistically evaluated using non-linear dynamic analyses based on the Monte-Carlo simulation sampling with the Latin hypercube method. The derivation of seismic fragility curves of the RC frame from the probabilistic distributions as the results of uncertainty-propagation and the verification of whether the RC frame can meet the seismic performance objective from a probabilistic point of view represent a novel and significant contribution to the field of structural engineering.
This study is about the evaluation for shock-proof performance of the system, elastically support the low accumulator of the naval artillery against underwater explosion, using DDAM. For the evaluation, the shock analysis procedure using DDAM, supported by MSC/NASTRAN, was briefly described. In addition, in order to perform the shock analysis, the elastic support system was modeled as a finite element. The shock analysis of the elastic support system was performed by selecting the analysis frequency range so that reliable results can be obtained. Finally, the shock-proof performance of the system was evaluated by comparing the shock analysis results with the properties of the elastic support system.
Recent advances in computer technology have made it possible to solve numerous challenges but require faster hardware development. However, the size of the classical computer has reached its physical limit, and researchers' interest in quantum computers is growing, and it is being used in various engineering fields. However, research using quantum computing in structural engineering is very insufficient. Therefore, in this paper, the characteristics of qubits, the minimum unit of quantum information processing, were grafted with the crow search algorithm to propose QCSA (quantum crow search algorithm) and compare the convergence performance according to parameter changes. In addition, by performing the optimal design of the example truss structure, it was confirmed that quantum computing can be used in the architectural field.
A cyclone separator is a device that separates solid particles from a fluid using centrifugal force and gravity in its inner chamber. Among cyclone separators, the separator that uses water as a working fluid is called as hydrocyclone separator, which has been developed for the purpose of dehydrating solid mixtures with a proportion of solids floating in liquids greater than 1, such as soil, coal, and cement slurry. In this paper, a hydrocyclone was designed based on the previously proposed design method, and how different the performance is from the targeted value was investigated using the computational fluid dynamics.
This study aims to present a performance based design for apartments through evacuation safety assessment and damage impact assessment due to acrylonitrile leakage. In the evacuation safety evaluation, ASET was analyzed as 25 min or more and 60 min or less when the ventilation rate was once per hour, and RSET was 22.6 min. Evacuation safety is satisfied when the number of ventilation per hour is less than 1, so it is necessary to design the number of ventilation to be 1 or less. In the damage impact assessment, the 0% structural collapse rate due to overpressure was measured to be between 71m and 90m, and the 0% fatality rate due to radiant heat was measured to be between 136m and 353m. Therefore, maintain a safe distance of 353m or more.
본 실험에서는 Ti를 기반으로 한 평판 수소 분리막을 설계하여 제조하였다. 새로운 조성의 Ti를 베이스로 한 수소 분 리막을 찾기 위하여 여러 합금들의 물리화학적 특성과 수소투과도 사이의 상관관계에 대해 조사하였다. 이를 바탕으로 신조성의 합금막 2종(Ti14.2Zr66.4Ni12.6Cu6.8 (70 μm), Ti17.3Zr62.7Ni20 (80 μm))을 설계 및 제조하였다. 제조된 평판 수소 분리막은 300~500°C, 1~4 bar의 조건에서 혼합 가스(H2, N2), sweep 가스(Ar)를 이용하여 수소 투과 실험을 진행하였다. Ti14.2Zr66.4Ni12.6Cu6.8 합금 막은 500°C, 4bar에서 최대 16.35 mL/cm2min의 flux를 가지며, Ti17.3Zr62.7Ni20 합금막은 450°C, 4 bar에서 최대 10.28 mL/ cm2min의 flux를 가진다.
본 연구에서는 공기역학적 형상변화의 풍하중 저감 측면에서의 효율성을 평가하기 위해 평면의 모서리 부분이 개선된 고층 건물에 대해 사례연구 기반의 비탄성 내풍설계를 수행하였다. 비선형 시간이력해석을 통해 다양한 설계풍속 및 항복 후 강성에 대한 구조물의 응답을 산정하였으며, 최근 국내 설계기준(KDS 41)에 도입된 성능기반내풍설계 개념을 토대로 구조물의 성능을 평가하였다. 해석 결과 공기역학적 형상변화를 갖는 구조물의 경우나 성능기반내풍설계를 적용했을 경우(또는 모두에 해당할 경우) 공진성분을 줄 여 구조물의 응답이 크게 감소함을 확인하였다.
The ductility of the system based on the capacity of each structural member constituting the seismic force-resisting system is a significant factor determining the structure’s seismic performance. This study aims to provide a procedure to supplement the current seismic design criteria to secure the system’s ductility and improve the seismic performance of the steel ordinary moment frames. For the study, a nonlinear analysis was performed on the 9- and 15-story model buildings, and the formation of collapse mechanisms and damage distribution for dynamic loads were analyzed. As a result of analyzing the nonlinear response and damage distribution of the steel ordinary moment frame, local collapse due to the concentration of structural damage was observed in the case where the influence of the higher mode was dominant. In this study, a procedure to improve the seismic performance and avoid inferior dynamic response was proposed by limiting the strength ratio of the column. The proposed procedure effectively improved the seismic performance of steel ordinary moment frames by reducing the probability of local collapse.
The purpose of this study is to propose measures to increase evacuation safety by calculating the habitable time using a fire and evacuation simulation program for the Room-escape cafe currently in operation, and comparing and analyzing it with the evacuation required time. Assuming a fire due to overheating of electric heaters in use in front of the warehouse, the habitable time was calculated through fire simulation, and the occupant's evacuation time calculated through evacuation simulation according installation of safety facilities, etc. was compared and analyzed with the habitable time. In the case of escape room cafes with safety facilities installed, evacuation safety was satisfied, but in escape room cafes without safety facilities, the evacuation safety was not secure. As a result of analyzing evacuation safety for each scenario based on the ASET analyzed in the fire simulation, it was found that in scenario 1, evacuation safety was secured and everyone successfully evacuated, while in scenario 2, no one succeeded in evacuation. These results can be said to confirm that the installation of safety facilities is very important in business establishments such as escape room cafes, which become enclosed structures when games are started.
본 연구는 EMG(electromyography) 텍스타일 전극 개발을 목적으로 레이어 수의 디자인 및 원단을 다르게 하여 성능 및 신호 획득 안정성을 평가한다. 레이징 및 프레스 공정을 통하여 텍스타일 전극을 제조하며 Layer-0, Layer-1, Layer-2로 레이어 유무 및 수에 따른 결과를 분석했다. 이에 레이어 유무에 따라서는 근활성 측정에 영향을, 수가 많을수록 높은 성능이 나타남을 확인할 수 있었다. Layer-2 구조로 통일하여 5가지의 원단(네오프렌, 스판덱스 쿠션, 폴리에스테르 100%, 나일론 스판덱스, 광목 캔버스)으로 전극을 제조해 실험해 보았다. 성능적인 면에서, 원단의 중 량이 높은 나일론 스판덱스가 높은 성능을 보였으며, 스판쿠션 텍스타일 전극이 근활성도 수득에 높은 안정성을 보 였다. 이에 위 연구는 레이어에 따른 성능 연관성과 전극-피부사이의 닿는 면적 간의 관계 등을 고찰하여 슬리브 전체의 의복압을 늘리는 대신 특정 센서 측정 부위에만 높은 압력을 가함으로 차후 연구에서 레이어의 수 및 물성에 따른 전극의 공학적 설계 가능성을 제시한 의의가 있다.
In this study, a prefabricated buckling brace (PF-BRB) was proposed, and a test specimen was manufactured based on the design formula for the initial shape and structural performance tests were performed. As a result of the experiment, all standard performance requirements presented by KDS 41 17 00 and MOE 2021 were satisfied before and after replacement of the reinforcement module, and no fracture of the joint module occurred. As a result of the incremental load test, the physical properties showed a significant difference in the stiffness ratio after yielding under the compressive load of the envelope according to the experimental results. It is judged necessary to further analyze the physical properties according to the experimental results through finite element analysis in the future.
Complaints about foul odors are emerging as an issue, and the number of complaints is steadily increasing every year. Biofiltration is known to remove harmful or odorous substances from the atmosphere by using microorganisms, and full-scale biofilters are being installed and operated in various environmental and industrial facilities. In this study, the current status and actual odor removal efficiency of full-scale biofilters installed in publicly owned treatment facilities such as sewage, manure, and livestock manure treatment plants were investigated. In addition, the effects of design and operating factors on their efficiency were also examined. As a result, it was found that odor prevention facilities with less than 30% odor removal efficiency based on complex odors accounted for 40%-50% of the biofilters investigated. In investigating the appropriate level of operating factors on odor removal efficiency, it was found that compliance with the recommended values p lays a significant role in improving odor removal efficiency. In the canonical correlation analysis for the on-site biofilter operation and design data, residence time and humidity were found to be the most critical factors. The on-site biofilter operation and design data were analyzed through canonical correlation analysis, and the residence time and humidity maintenance were found to be the most important factors in the design and operations of the biofilter. Based on these results, it is necessary to improve the odor removal efficiency of on-site biofilters by reviewing the effectiveness of the operation factors, improving devices, and adjusting operating methods.