• Title/Summary/Keyword: Beam-Columns

Search Result 514, Processing Time 0.019 seconds

An Experimental Study on the Buckling Strength of subject to Asymmetrical Double Curvature Stainless Steel Circular Hollow Section Beam-Columns (비대칭 이중곡률 스테인리스 원형강관 보-기둥의 좌굴내력에 관한 실험적 연구)

  • Jang, Ho Ju;Park, Jae Seon;Yang, Young Sung
    • Journal of Korean Society of Steel Construction
    • /
    • v.21 no.4
    • /
    • pp.351-360
    • /
    • 2009
  • This study is a series of experimental investigations of the buckling strengths of eccentrically compressed, cold-formed, stainless-steel, circular, hollow-section beam columns. The principal parameters that were used in this study were the slenderness ratios (Lk/r = 30, 50, 70) and the magnitude of eccentricity e(one way: 0, 25, 50, 75, and 100mm: the other way: 0, 12.5, 25, 37.5, and 50mm) on the asymmetrical end-moment of a double curvature. The objectives of the study were to obtain the maximum loads through an experiment and to compare the experimental behaviors with the analysis results. The ultimate buckling strength of the square section members were evaluated using a numerical method, in accordance with the bending moment-axial force(M-P) interaction curves. The behavior of each specimen was displayed in the form of the strength-displacement and moment-angle(M-$\theta$) relationship.

Influence of joint modelling on the pushover analysis of a RC frame

  • Costa, Ricardo;Providencia, Paulo;Ferreira, Miguel
    • Structural Engineering and Mechanics
    • /
    • v.64 no.5
    • /
    • pp.641-652
    • /
    • 2017
  • In general, conventional analysis and design of reinforced concrete (RC) frame structures overlook the role of beam-column (RCBC) joints. Nowadays, the rigid joint model is one of the most common for RCBC joints: the joint is assumed to be rigid (unable to deform) and stronger than the adjacent beams and columns (does not fail before them). This model is popular because (i) the application of the capacity design principles excludes the possibility of the joint failing before the adjacent beams and (ii) many believe that the actual behaviour of RCBC joints designed according to the seismic codes produced mainly after the 1980s can be assumed to be nominally rigid. This study investigates the relevance of the deformation of RCBC joints in a standard pushover analysis at several levels: frame, storey, element and cross-section. Accordingly, a RC frame designed according to preliminary versions of EN 1992-1-1 and EN 1998-1 was analysed, considering the nonlinear behaviour of beams and columns by means of a standard sectional fibre model. Two alternative models were used for the RCBC joints: the rigid model and an explicit component based nonlinear model. The effect of RCBC joints modelling was found to be twofold: (i) the flexibility of the joints substantially increases the frame lateral deformation for a given load (30 to 50%), and (ii) in terms of seismic performance, it was found that joint flexibility (ii-1) appears to have a minor effect on the force and displacement corresponding to the performance point (seismic demand assessed at frame level), but (ii-2) has a major influence on the seismic demand when assessed at storey, element and cross-section levels.

Behavior of Concrete-Filled Square Tubular Beam-Column under Cyclic Load (반복하중을 받는 콘크리트충전 각형강관 보-기둥의 거동)

  • Kang, Chang-Hoon;Moon, Tae-Sup
    • Journal of Korean Society of Steel Construction
    • /
    • v.12 no.4 s.47
    • /
    • pp.387-395
    • /
    • 2000
  • The purpose of this research is to evaluate the capacity of strength and plastic deformation of those members, and provide experimental data on the seismic behavior of these members as a basis for developing guidelines for designing seismically resistant concrete-filled steel tubular columns. Eighteen cantilever-type specimens were tested under constant axial load and cyclically lateral load as models of bottom columns in high-rise building. The parameters studied in the test program included, are width-thickness ratio of steel tube, slenderness ratio (Lo/D) and axial force ratio. From the test results, the effects of parameters on the strength, the deformation capacity, energy absorption capacity are discussed. The specimen flexural capacity under combined axial and lateral loading was found to be almost accurately predicted by criteria AIJ and AISC-LRFD providing conservative results. Therefore KSSC for encased composite column can be applied to the concrete filled column if composite section and elastic modulus are modified according to AIJ and AISC-LRFD. Finally, the proposed flexural capacity considering confinement effects is a food agreement on the tests results.

  • PDF

Dynamic Behavior of 2D 8-Story Unbraced Steel Frame with Partially Restrained Composite Connection (합성반강접 접합부를 갖는 2차원 8층 비가새 철골골조의 동적거동)

  • Kang, Suk Bong;Lee, Kyung Taek
    • Journal of Korean Society of Steel Construction
    • /
    • v.19 no.5
    • /
    • pp.503-513
    • /
    • 2007
  • The seismic responses of a building are affected by the connection characteristics that have effects on structural stiffness. In this study, push-over analysis and time history analysis were performed to estimate structural behavior of 2D eight-story unbraced steel structures with partially restrained composite connections using a nonlinear dynamic analysis program. Nonlinear $M-{\theta}$characteristics of connection and material inelastic characteristics of composite beam and steel column were considered. The idealization of composite semi-rigid connection as fully rigid connection yielded an increase in initial stiffness and ultimate strength in the push-over analysis. In time history analysis, the stiffness and hysteretic behavior of connections have effects on base-shear force, maximum story-drift and maximum moment in beams and columns. For seismic waves with PGA of 0.4 g, the structure with the semi-rigid composite connections shows the maximum story-drift with less than the life safety criteria by FEMA 273 and no inelastic behavior of beam and column, whereas in the structure with rigid connections, beams and columns have experienced inelastic behaviors.

Loading Rate Effect on the Lateral Response of H-Shape Steel Column (재하속도가 H-형강 기둥부재의 횡방향 거동에 미치는 영향)

  • Park, Minseok;Kim, Chul-Young;Han, Jongwook;Chae, Yunbyeong
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.41 no.6
    • /
    • pp.637-644
    • /
    • 2021
  • Dynamic response of structures can be evaluated experimentally by conducting cyclic loading tests. It has been known that steel materials are rate-dependent and the lateral response of a structure is significantly affected by the presence of axial force. However, the rate-dependency of steel column structures subjected to both axial and lateral loads has not been sufficiently studied yet due to the difficulty of controlling the axial force in a real-time manner during test. This study introduces an advanced way to apply the axial load in real-time to a column specimen using the adaptive time series (ATS) compensator and the flexible loading beam (FLB), where the H-shape steel columns made of SS275 are used for monotonic and cyclic loading tests with various loading rates with axial loads. The lateral strength and post-yield response of the steel columns are compared for each of monotonic and cyclic loading tests. The estimating equation of yield stress of various strain rate has proposed and finite element analysis were performed for comparison.

An Experimental Study on Punching Shear at the Connection of RC Column Constrained by H-Beam with 井 Shape (정(井)자형 H형강으로 구속된 철근콘크리트 기둥접합부의 뚫림전단에 관한 실험적 연구)

  • Kim, Lyang-Woon;Lee, Soo-Kueon;Lee, Jung-Yoon;Chung, Chang-Yong;Kim, Sang-Sik
    • Journal of the Korea Concrete Institute
    • /
    • v.21 no.3
    • /
    • pp.319-326
    • /
    • 2009
  • Two parallel wide flange built-up beams are widely used as struts in resisting lateral earth pressure because of the effectiveness in structure and construction. In a certain structural system, the reinforced concrete columns are to be placed at the intersection where two perpendicular beams cross each other, the square part of the joint being filled with concrete. In the punching shear mechanism of the beam-column joint, the radial deformation caused due to shear cracking will be constrained by the spring action of the squarely encompassed beam flanges. As a result, the punching shear strength of the joint concrete can be expected to be increased. To verify this phenomenon experiments have been performed for various constraining elements and distances between columns and constraints. Test results are compared with the approximation analysis formula which has been proposed in this study, based on the code formula. The results calculated by the proposed equation show comparatively close agreement with the punching shear strength detected from the test.

Performance Evaluation of Steel Moment Frame and Connection including Inclined Column (경사기둥을 포함한 철골모멘트 골조 및 접합부의 성능평가)

  • Kim, Yong-Wan;Kim, Taejin;Kim, Jongho
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.26 no.3
    • /
    • pp.173-182
    • /
    • 2013
  • The building design projects which are being proceeded nowadays pursue a complex and various shape of structures, escaping from the traditional and regular shape of buildings. In this new trend of the architecture, there rises a demand of the research in the structural engineering for the effective realization of such complex-shaped buildings which disassembles the orthogonality of frames. As a distinguished characteristics of the buildings in a complex-shape, there frequently are inclined columns included in the structural frame. The inclined column causes extra axial force and bending moment at the beam-column connection so it is necessary to assess those effects on the structural behavior of the frame and the connection by experiment or analysis. However, with comparing to the studies on the normal beam-column connections, the inclined column connections have not been studied sufficiently. Therefore, this study evaluated the beam-column connections having an inclined column using nonlinear and finite element analysis method. In this paper, steel moment frames having inclined columns were analyzed by the nonlinear pushover analysis to check the global behavior and beam-column connection models were analyzed by the finite element analysis to check the buckling behavior and the fracture potentials.

Study on seismic performance of connection joint between prefabricated prestressed concrete beams and high strength reinforcement-confined concrete columns

  • Jiang, Haotian;Li, Qingning;Jiang, Weishan;Zhang, De-Yi
    • Steel and Composite Structures
    • /
    • v.21 no.2
    • /
    • pp.343-356
    • /
    • 2016
  • As the common cast-in-place construction works fails to meet the enormous construction demand under rapid economic growth, the development of prefabricated structure instead becomes increasingly promising in China. For the prefabricated structure, its load carrying connection joint play a key role in maintaining the structural integrity. Therefore, a novel end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column was proposed. Under action of low cycle repeated horizontal loadings, comparative tests are conducted on 6 prefabricated pre-stressed intermediate joint specimens and 1 cast-in-place joint specimen to obtain the specimen failure modes, hysteresis curves, skeleton curves, ductility factor, stiffness degradation and energy dissipation capacity and other seismic indicators, and the seismic characteristics of the new-type prefabricated beam-column connecting joint are determined. The test results show that all the specimens for end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column have realized the design objectives of strong column weak beam. The hysteretic curves for specimens are good, indicating desirable ductility and energy dissipation capacity and seismic performances, and the research results provide theoretical basis and technical support for the promotion and application of prefabricated assembly frames in the earthquake zone.

Slab Effect on Inelastic Behaviors of High Strength RC Beam-Column Joints (고강도 RC 보-기둥 접합부의 비탄성 거동에 대한 슬래브의 영향)

  • 장극관;김윤일;오영훈
    • Magazine of the Korea Concrete Institute
    • /
    • v.9 no.2
    • /
    • pp.167-177
    • /
    • 1997
  • In thtx design of ductile moment -1csist1ng frnmcls (DMRFs) f'ollow~ng the. stlong columnweakbeam design philosophy, it is desirable that the joint and column remain essentiallyelastic in order to insure proper energy dissipation and lateral stability of the structure.Thv joint has been identifid as the "weak link: in DMRFs because any stiffness orstrength deterioration in this region can lead to substantial drifts and the possibility ofcollapse due to t'-delta effects. h3oreove1.. the tngintw is faced with the difficult task ofdetailing an element whose size is determined by theframing members, but \vhich mustresist a set of loads very different from those used in the design of the beams and columns.Four 3 -scale beam-column-slab joint assemblies were designed according to existing cod\ulcornerrequirements of' ACI 318-89. representing perimeter joints of DMRFs with reinforced highstrength concrete. The influence on aseismic behavior of beam-column joints due tomonolithic slab, has been investigated.lab, has been investigated.

Behavior Evaluation on the Non-symmetric Composite Column for Unit Modular Frames (모듈러 골조용 비대칭 기둥-보 접합부에 대한 거동 평가)

  • Park, Keum-Sung;Lee, Sang-Sup;Bae, Kyug-Woong;Moon, Ji-Ho
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.23 no.1
    • /
    • pp.36-44
    • /
    • 2019
  • The purpose of this study is to evaluate the structural performance of press-formed type asymmetric column to beam connections of steel-PC composite module frames. Most of the column sections of the joints making up the modular frame use a closed square steel section. The column-beam connection using the closed column section has difficulty in reducing the workability and securing the fire resistance. In order to overcome this disadvantage, concrete is filled in the asymmetrical open type cross section of the steel plate by press forming. A total of four specimens were fabricated to investigate the structural performance of press formed type asymmetric column to beam connections. The experimental results show that the structural performance and behavior of the asymmetric columns are different depending on whether the asymmetric column cross section is composited or the column width thickness ratio. The structural performance of the press formed type asymmetric column to beam connection was evaluated by comparing the experimental results with the theoretical formulas.