• Title/Summary/Keyword: collapse design

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Seismic performance evaluation of steel moment frames with self-centering energy-dissipating coupled wall panels

  • Lu Sui;Hanheng Wu;Menglong Tao;Zhichao Jia;Tianhua Zhou
    • Steel and Composite Structures
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    • v.47 no.5
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    • pp.663-677
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    • 2023
  • The self-centering energy-dissipating coupled wall panels (SECWs) possess a dual capacity of resiliency and energy dissipation. Used in steel frames, the SECWs can localize the damage of structures and reduce residual drifts. Based on OpenSEES, the nonlinear models were established and validated by experimental results. The seismic design procedure of steel frame with SECW structures (SF-SECW) was proposed in accordance with four-level seismic fortification objectives. Nonlinear time-history response analyses were carried out to validate the reasonability of seismic design procedure for 6-story and 12-story structures. Results show that the inter-story drifts of designed structures are less than drift limits. According to incremental dynamic analyses (IDA), the fragility curves of mentioned-above structure models under different limit states were obtained. The results indicate that designed structures have good seismic performance and meet the seismic fortification objectives.

Mechanical Property and Problems of the Self-expandable Metal Stent in Pancreaticobiliary Cancer

  • Thanawat Luangsukrerk
    • Journal of Digestive Cancer Research
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    • v.10 no.2
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    • pp.92-98
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    • 2022
  • Self-expandable metal stent (SEMS) is effective for biliary drainage, especially in pancreaticobiliary cancer. The mechanical properties, material, and design of SEMS are important in preventing recurrent biliary obstruction and complication. Radial and chronic expansion forces play roles in preventing stent migration and collapse. Complications, such as stent impaction, cholecystitis, and pancreatitis, were related to the axial force. The nickel-titanium alloy shows more flexibility, conformability, and optimal axial force compared to previously used stainless steel. Additionally, the stent structure affected the mechanical properties of SEMS. Therefore, understanding the mechanical properties, material, and design of SEMS will provide the best outcome for biliary drainage, as well as better SEMS development.

An analytical approach for offshore structures considering soil-structure interaction

  • Ali Sari;Kasim Korkmaz
    • Advances in Computational Design
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    • v.9 no.1
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    • pp.25-38
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    • 2024
  • This paper presents an advanced analytical approach for the design and analysis of fixed offshore structures with soil structure interaction considered. The proposed methodology involves conducting case studies to illustrate and assess the structural response of a structure considering seven different earthquakes, with the primary goal of ensuring there is no global collapse in the structures. The case studies focus on developing a model for structural analysis and its topside, incorporating nonlinear axial and lateral springs to capture soil-pile interaction. Additionally, mass and damping ratios are considered through the use of dashpots in the analyses. Finite Element Software was employed for structural analyses with detailed modeling, with soil spring nodes applied in the entire structure across various depths. After the finite element analysis was carried out, a sensitivity analysis was conducted to quantify and report the effects of different parameters.

Evaluation and Improvement of Deformation Capacities of Shear Walls Using Displacement-Based Seismic Design

  • Oh, Young-Hun;Han, Sang-Whan;Choi, Yeoh-Soo
    • International Journal of Concrete Structures and Materials
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    • v.18 no.1E
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    • pp.55-61
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    • 2006
  • RC shear walls are frequently used as lateral force-resisting system in building construction because they have sufficient stiffness and strength against damage and collapse. If RC shear walls are properly designed and proportioned, these walls can also behave as ductile flexural members like cantilevered beams. To achieve this goal, the designer should provide adequate strength and deformation capacity of shear walls corresponding to the anticipated deformation level. In this study, the level of demands for deformation of shear walls was investigated using a displacement-based design approach. Also, deformation capacities of shear walls are evaluated through laboratory tests of shear walls with specific transverse confinement widely used in Korea. Four full-scale wall specimens with different wall boundary details and cross-sections were constructed for the experiment. The displacement-based design approach could be used to determine the deformation demands and capacities depending on the aspect ratio, ratio of wall area to floor plan area, flexural reinforcement ratio, and axial load ratio. Also, the specific boundary detailing for shear wall can be applied to enhance the deformation capacity of the shear wall.

A Comparative Study on the Earthquake Resistant Design Criteria for Cylindrical, Liquid-Storage Tanks (원통형 액체저장탱크 내진설계기준의 비교연구)

  • 국승규
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.2
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    • pp.69-75
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    • 1998
  • Because the collapse of liquid-storage tank structures under earthquakes brings out substantially more damages by indirect effects(continuous losses of economy and environmental disruption due to the spillage of toxic contents or pollutants) than direct economic losses of tanks and contents, it is an urgent matter to provide earthquake resistant design criteria in order to minimize such direct/indirect damages. In this paper, as fundamental works to prepare earthquake resistant design criteria for cylindrical liquid-storage tanks, analysis methods given in the Recommendations of New Zealand and Austria are reviewed and the applicabilities and problems of the two methods are set forth by comparison of the analysis results with a numerical example.

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Interaction assessment and optimal design of composite action of plastered typha strawbale

  • Olatokunbo, Ofuyatan;Adeola, Adedeji;Maxwell, Omeje;Simon, Olawale
    • Advances in materials Research
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    • v.6 no.2
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    • pp.221-231
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    • 2017
  • The concept design of the typha strawbale masonry came up as a result of the urgent demand for a means of constructing sustainable buildings, both in rural and urban settlement, not only suitable for dwellers but for keeping farm products by structures that will respond to the environmental eco-system, coupled with the fact that such structures are also affordable, durable and easy to maintain during their service period. The effects of contact between plaster and the stacked strawbale of a masonry needs to be established and design optimization for durability and stability of the masonry be obtained. The assessment will involve the application of plaster materials (cement and natural earth) to the wall specimen panels. Past works have shown that plastered strawbale walls have adequate resistance against the appropriate vertical loads, and further showed that the earth plaster can bear higher stress than the cement plastered straw bale. There is the implication that the collapse or response of the earth-strawbale wall is significantly higher compared to that of cement-strawbale from other straw-based masonries. Therefore the allowable stresses of plastered typha strawbale shall be predicted for their optimum values using SAP2000. The stress stability of each masonry is obtained by analytical model using the best fit variables for the wall height and thickness.

Evaluation of Limiting Temperatures of Rectangular Hollow Sections (각형 강관기둥부재의 한계온도 평가 연구)

  • Kwon, In-Kyu
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.331-332
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    • 2012
  • Structural steel has been used as a primary materials to columns and beams since 1960's in Korea with an advantages of excellent of load-bearing capacity and design flexibility, and faster construction. However, if the steel columns made of structural steel exposed to fire the load-bearing capacity is going down steadily and finally reach to collapse. Therefore, building regulation requires fire resistance according to building occupation, scales. The fire resistance can be evaluated two categories. One is prescriptive method that is based on building regulation, specification and so on and the other is performance-based fire engineering method. The latter can be designed based on scientific and engineering consequences. The easiest evaluation way using the fire engineering design is comparing to the limiting temperature and maximum temperature calculated based on heat transfer theory. If the limiting temperature of a column exceeds the maximum temperature of it, the column can carry the load during the fire. Therefore, the database of limiting temperature is very essential for evaluation of column. In this paper, to build the database of column made of rectangular hollow sections 8 fire tests with loading were conducted and the relation between the limiting temperature and the applied loads showed in reverse proportion.

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On the Improvement for Design Methods of Luminaire Supports Based on the Structural Safety (구조안전성 기반의 가로등주 설계개선방안)

  • Jung, Soo Hyung;Shim, Jae Soo;Choi, Hyun Gyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.6
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    • pp.45-55
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    • 2012
  • The road luminaires have been treated as subsidiary electric apparatuses in the road although they are indispensable facilities which people use the road safely. Because of this misunderstanding, there are not many researches on luminaire supports against the wind loads. Therefore, a typhoon has overturned or damaged many luminaire supports without having sufficient structural safeties. The purpose of this study is to review the current design criteria and to suggest the improvement of design methods based on the structural safety and compatible with the site conditions of luminaire supports. The stress concentration around the inspection hole, which causes the collapse of luminaire supports, is analyzed and stress reduction method is suggested with the improved design methods.

Domestic current situation and Improvement plan Consideration of Electricity Design&Supervision System (전기설계.감리제도의 국내.외 현황 및 개선방안 고찰)

  • Nam, Gi-Beom;Lee, Jong-Hyeok;Jeon, Yeong-SU;Yang, Sun-Sik
    • Proceedings of the KIEE Conference
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    • 2005.11c
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    • pp.14-18
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    • 2005
  • The Reason of collapse accidents, Seongsu bridge Accident in 1994 and Sampung department store Accident in 1995 and so on, that is found out to the shortage construction. Consequently, depending on orderer's self-regulating judgement the meanwhile, Electricity Technique Administration Law in 1995 owes at the public opinion to need the plan of a law system device about the electricity design and supervision and is born. This various issue problem, the combined ordering with Constructing, Electricity, fire-fighting, Information & Communication and so on, field problem, low cost services, the problem about the selection procedure of the design and supervision businessman, the business range between general and specialized, which the system appears as are carried out have been risen. Therefore basic solution plan about this have been desired. We consider a domestic current situation about an electricity design supervision system in this paper, and try to present the plan for healthy upbringing development of the electricity industry through this.

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Seismic Performance Evaluation According to Rotation Capacity of Connections for Intermediate Steel Moment Frames - II. Cause Evaluation and Alternative (접합부 회전성능에 따른 중간 철골 모멘트 골조의 내진 성능 평가 - II 원인 평가 및 대안)

  • Moon, Ki Hoon;Han, Sang Whan;Ha, Seung Jin
    • Journal of the Earthquake Engineering Society of Korea
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    • v.18 no.2
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    • pp.105-115
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    • 2014
  • This paper is the sequel of a companion paper (I. Performance Evaluation) evaluating the relation between the seismic performance of steel intermediate moment frames (IMFs) and the rotation capacity of connections. The evaluation revealed that the seismic performance of IMFs having the required minimum rotation capacity suggested in the current standards did not meet the seismic performance criteria presented in FEMA 695. Therefore, thepresent study evaluates the causes of the vulnerable seismic performance for steel IMFs and proposes alternatives to satisfy the seismic performance suggested in FEMA 695. To that goal, the results of nonlinear analysis, which are the pushover analysis and the incremental dynamic analysis, are examined and evaluated. As a result, high-rise IMF systems are seen to have the lower collapse margin ratio after connection fracture than row-rise IMF systems and, the actual response isfound to compared tothedesign drift ratio acting on design load design. Finally, the minimum design load values are proposed to meet the seismic performance suggested in FEMA 695 for IMF systems having vulnerable seismic performance.