• 제목/요약/키워드: load to capacity ratio

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Effect of Span-to-Depth Ratio on Behavior and Capacity in Composite Structure of Sandwich System (샌드위치식 복합구조체의 셀(Cell)형상비가 거동과 성능에 미치는 영향)

  • 정연주;정광회;김병석;박성수;황일선
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.10a
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    • pp.73-78
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    • 2000
  • This paper describes the effect of span-to-depth ratio, which describes aspect of cell formed with top diaphragm steel plate, on capacity in composite steel-concrete structure of sandwich system. The span-to-depth ratio \ulcorner load-carrying mechanism and load-distribution capacity of structure. Therefore, stress levels of members and load-resis\ulcorner of system vary according to span-depth ratio. In this study, numerical nonlinear analysis was performed to various ratio for two types(MA, MB) composite structure of sandwich system to analyze the influence of span-to-depth ratio or, behavior. The difference of load-carrying mechanism and stress of members results from analysis results, then bas\ulcorner differences, the effects of span-to-depth ratio on shear capacity, flexural capacity and load-resistance capacity were analyze effects on failure mode and ductility were briefly. As a results of this study, as span-to-depth ratio increases, \ulcorner bottom steel plate and concrete lower. This implies an increase in effective flexural and shear capacity. Therefore lo\ulcorner capacity of structure improves as span-to-depth ratio increases, Especially, the effect is greate in shear than flexural span-to-depth ratio increases, this difference between flexural and shear capacity may change failure mode and ductility. span-to-depth ratio increases capacity increases more than flexural capacity, we should expect that structural behavior mode gradually change from shear to flexural and ductility of structure gradually improves.

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A Study on Design Parameters to Improve Load Capacity of Spiral Grooved Thrust Bearing (스파이럴 그루브 스러스트 베어링의 부하용량 향상을 위한 설계 변수에 대한 연구)

  • 강지훈;김경웅
    • Tribology and Lubricants
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    • v.18 no.3
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    • pp.181-186
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    • 2002
  • A numerical analysis is undertaken to show the influence of bearing design parameters on the load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, and the seal ratio.

A Study on the Loading Capacity Standard of Bi-directional Pile Load Test (BD PLT) (양방향말뚝재하시험의 재하용량 기준에 관한 연구)

  • Choi, Yongkyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6C
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    • pp.379-388
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    • 2008
  • In the bi-directional pile load test (BD PLT) for pile load tests of Mega pile foundations, loading capacity standard is not specified exactly. Therefore there are so many confusions in performing the BD PLT and variations up to maximum 2 times in loading capacity are come out. In this study, standards of bi-directional pile load test (BD PLT) were considered. Based on cases of the bi-directional pile load test performed in domestic areas, maximum equivalent test load, test load increasing ratio, loading capacity increasing ratio and sufficiency ratio of design load were analyzed. It could be known that the loading capacity standard of bi-directional pile load test must be defined as 1-directional loading capacity and also must be established as more than 2 times of design load.

Experimental and analytical research on geopolymer concrete beams reinforced with GFRP bars

  • Suleyman Anil Adakli;Serkan Tokgoz;Sedat Karaahmetli;Cengiz Dundar
    • Structural Engineering and Mechanics
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    • v.91 no.4
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    • pp.335-347
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    • 2024
  • This paper presents the behavior of geopolymer concrete beams reinforced with glass fiber reinforced polymer (GFRP) bars. In the study, ordinary Portland cement concrete and geopolymer concrete beams having GFRP bars were prepared and tested under four-point loading. The load-deflection diagrams and load capacities of the tested beams were obtained. It was observed that the tested beams exhibited good ductility and significant deflection capacity. The results showed that increasing the tension GFRP reinforcement ratio caused enhancement in the strength capacity of geopolymer concrete beams. In addition, the tested beams were analyzed to obtain the load capacity and the load-deflection responses. The theoretical load-deflection curves and load bearing capacities have been predicted well with the test results. Parametric study has been performed to determine the influences of concrete strength, shear span to depth ratio (a/d) and reinforcement ratio on the behavior of geopolymer concrete beams longitudinally reinforced with GFRP bars. It was concluded that increasing concrete strength led to an increase in load capacity. Besides, the ultimate load increased as the reinforcement ratio increased. On the other hand, increasing a/d ratio reduced the ultimate load value of GFRP reinforced geopolymer concrete beams.

A Study on The Load Capacity of Doubly-Stepped Journal Bearing (공기윤활베어링의 부하용량 증대에 관한 연구)

  • ;;Kim, Hho Jung
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.3 no.1
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    • pp.35-41
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    • 1979
  • In order to improve the load capacity of externally pressurized air-lubeicatedjournal bearings, a new type(doubly-stepped type) bearing was revised and experimented. Through the results of experiment, the load capacity of doubly-stepped bearings was discussed and compared with equivalent conventional circular journal bearings. Results were obtained for speed up to 18000rpm and for supply pressure ratio(Ps/Pa) 4.8,6,7. Compared with equivalent conventional bearings, doubly-stepped bearings resultd a high gain in load capacity. It is also shown that the increasing rate of load capacith increases with decreasing the eccentricity ratio. Furthermore, the increasing rate is higher in the case of great clearanceratio than small dleatance ratio of doubly-stepped bearings. Such an increase in load capacity is confirmed by pressure distributions in the bearings.

Experimental research on seismic behavior of steel reinforced high-strength concrete short columns

  • Zhu, Weiqing;Jia, Jinqing;Zhang, Junguang
    • Steel and Composite Structures
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    • v.25 no.5
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    • pp.603-615
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    • 2017
  • This experimental research presents the seismic performance of steel reinforced high-strength concrete (SRHC) short columns. Eleven SRHC column specimens were tested under simulated earthquake loading conditions, including six short column specimens and five normal column specimens. The parameters studied included the axial load level, stirrup details and shear span ratio. The failure modes, critical region length, energy dissipation capacity and deformation capacity, stiffness and strength degradation and shear displacement of SRHC short columns were analyzed in detail. The effects of the parameters on seismic performance were discussed. The test results showed that SRHC short columns exhibited shear-flexure failure characteristics. The critical region length of SRHC short columns could be taken as the whole column height, regardless of axial load level. In comparison to SRHC normal columns, SRHC short columns had weaker energy dissipation capacity and deformation capacity, and experienced faster stiffness degradation and strength degradation. The decrease in energy dissipation and deformation capacity due to the decreasing shear span ratio was more serious when the axial load level was higher. However, SRHC short columns confined by multiple stirrups might possess good seismic behavior with enough deformation capacity (ultimate drift ratio ${\geq}2.5%$), even though a relative large axial load ratio (= 0.38) and relative small structural steel ratio (= 3.58%) were used, and were suitable to be used in tall buildings in earthquake regions.

A Study on Design Parameters to Improve Load Capacity of Spiral Grooved Thrust Bearing (스파이럴 그루브 형상의 스러스트 베어링의 부하용량 향상을 위한 설계 변수에 대한 연구)

  • 강지훈;김경웅
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.257-262
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    • 2001
  • A numerical analysis is undertaken to show tile influence of bearing design parameters on tile load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, arid the seal ratio.

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Cyclic tests and numerical study of composite steel plate deep beam

  • Hu, Yi;Jiang, Liqiang;Zheng, Hong
    • Earthquakes and Structures
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    • v.12 no.1
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    • pp.23-34
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    • 2017
  • Composite steel plate deep beam (CDB) is proposed as a lateral resisting member, which is constructed by steel plate and reinforced concrete (RC) panel, and it is connected with building frame through high-strength bolts. To investigate the seismic performance of the CDB, tests of two 1/3 scaled specimens with different length-to-height ratio were carried out under cyclic loads. The failure modes, load-carrying capacity, hysteretic behavior, ductility and energy dissipation were obtained and analyzed. In addition, the nonlinear finite element (FE) models of the specimens were established and verified by the test results. Besides, parametric analyses were performed to study the effect of length-to-height ratio, height-to-thickness ratio, material type and arrangement of RC panel. The experimental and numerical results showed that: the CDBs lost their load-carrying capacity because of the large out-of plane deformation and yield of the tension field formed on the steel plate. By increasing the length-to-height ratio of steel plate, the load-carrying capacity, elastic stiffness, ductility and energy dissipation capacity of the specimens were significantly enhanced. The ultimate loading capacity increased with increasing the length-to-height ratio of steel plate and yield strength of steel plate; and such capacity increased with decreasing of height-to-thickness ratio of steel plate and gap. Finally, a unified formula is proposed to calculate their ultimate loading capacity, and fitting formula on such indexes are provided for designation of the CDB.

Effect of Diaphragm Ratio by Load Condition and Behavior in Composite Structures of Sandwich System (샌드위치식 복합구조체에서 하중조건.거동특성에 따른 격벽간격비의 영향)

  • 정연주;정광회;김병석;박성수;황일선
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.297-302
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    • 2000
  • This paper presents the effect of diaphragm spacing ratio(depth to span) on behavior and capacity of composite steel-concrete structures of sandwich system. Numerical analysis has been performed variety diaphragm ratio, behavior and load condition. As a results of this study, in case of shear behavior and concentrated load, the capacity of structure such as yielding and ultimate load improve according to diaphragm ratio because of concrete confining effect by steel plate and stress redistribution by diaphragm. But in case of bending behavior or uniform load, it proved that diaphragm ratio don't influence on behavior and capacity of composite structures of sandwich system.

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The Lateral Load Capacity of Bored-Precast Pile Depending on Injecting Ratio of Cement Milk in Sand (사질토 지반에서 시멘트밀크 주입비에 따른 매입말뚝의 수평지지력)

  • Hong, Won-Pyo;Yun, Jung-Mann
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.4
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    • pp.99-107
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    • 2013
  • In order to investigation Lateral bearing capacity of bored-precast pile, we carried out the analysis of the relationship between Lateral load and horizontal displacement using the result of horizontal pile load test. The six piles injected cement milk of 50%, 70% and 100% of the embedded length of pile were used in the horizontal pile load test. The horizontal displacement, yielding load and horizontal bearing capacity are mainly affected by The injecting ratio of cement milk (injected length of cement milk/embedded length of pile). As the injecting ratio of cement milt is increased, the starting point of horizontal displacement in piles become close to the ground surface and the amount of horizontal displacement is decreased. Also, the horizontal bearing capacity and yielding load are highly increased with increasing the ration of cement milk. The horizontal bearing capacity and yielding load of bored pile with 1 of cement milk ratio are about two or three times those of pile with 0.5 of cement milk ratio.