Assessment of a New Semi-Rigid Model in Steel Beam-to-Column Connections

2007 ◽  
Vol 353-358 ◽  
pp. 2081-2084
Author(s):  
Cheol Min Yang ◽  
Young Moon Kim ◽  
Nag Ho Ko ◽  
Dong Pyo Hong

This paper proposes a new semi-rigid detail used high-strength bolts for use in earthquake resistant structures. These specimens were single-side beam-to-column assemblies that are representative of exterior beam-to-column connections, and they were composed of identical beam and column but had the different connection details, respectively. All beam-to-column assembly required no welding. Specimen 1 (TSD) was standard Top-Seat-Double-web-angle but specimen 2 (MTSD) was made by modified shape. Two high-strength bolted steel semi-rigid connections were prepared and cyclic load was applied to each test specimen using displacement control. The cyclic load and displacements, moment-rotation plots, and the deformation pattern or failure modes for all the test cases are presented. The strength, stiffness, energy, and ductility of the tested connections are compared to each other.

2021 ◽  

As a promising composite structure, gangue concrete filled steel tubular (GCFST) column exhibites favarable characteristics including high strength and economic efficiency. This paper conducted numerical investiagations on structural behavior of a ring-beam connection to GCFST column with concrete beam under cyclic loading. Furthermore, finite element models of column-beam connections were developed using ABAQUS and validated against full-scale experimental tests to identify accuracy of selected modeling approaches. Using these validated models, stress distribution of each component was examined to study the force-transferring mechanism among the components and failure modes of the ring-beam connection. Research study indicated that the ring-beam connection showed a reasonable force-transferring mechanism under cyclic loading and the remarkable earthquake-resistant performance with high capacity and acceptable ductility. Finally, parametric studies were performed to assess the influences of beam-to-column stiffness ratio,steel ratio, axial load level, and concrete compressive strength on connection cyclic behaviors. Parametric studies provided some suggestions and references for the application of the ring-beam connection in various engineering projects.


2013 ◽  
Vol 838-841 ◽  
pp. 559-563
Author(s):  
Liu Sheng Duan ◽  
Ming Zhou Su ◽  
Hui Li

High strength steel composite K-type eccentrically braced frame is a new structural system, in which the link is made from low yield point steel and the others are made from high strength steel. In order to study the seismic behavior of such a structure, four one-bay one-story 1/2 scaled plane specimens were tested under the monotonic and cyclic load respectively. The failure modes and the main indexes of seismic behavior of specimens with various links length were analyzed. The results show that this new structural form is good at energy dissipation and ductility, and the way of energy absorbing by shear yield is better than by flexure yield. Under cyclic load, the main failure were concentrated at links, while the other parts of the eccentrically braced frame kept in elastic status. This kind of structure is an excellent dual resistance system and easy to rehabilitate after earthquake.


1975 ◽  
Vol 2 (3) ◽  
pp. 321-344 ◽  
Author(s):  
Thomas Paulay

This presentation, taking the form of a state of the art report, considers several aspects of the behavior of tall and squat shear walls. In particular the problems of brittle and ductile failure modes, diagonal tension, construction joints, alternating plasticity, sliding shear, stiffness degratation, and strength loss under reversed cyclic loading are discussed. The behavior of coupled shear walls is examined in some detail and the problems related to the components of this structure are reviewed. The principles rather than techniques of design for earthquake resistance are stated. Wherever possible the issues are studied against the background of experimental evidence. The material presented indicates that carefully detailed shear walls, designed to possess an intelligent hierarchy in their failure mechanisms, can be made to possess the properties so desirable in earthquake resistant structures.


Author(s):  
Yifan Li ◽  
Huaiyuan Gu ◽  
Martyn Pavier ◽  
Harry Coules

Octet-truss lattice structures can be used for lightweight structural applications due to their high strength-to-density ratio. In this research, octet-truss lattice specimens were fabricated by stereolithography additive manufacturing with a photopolymer resin. The mechanical properties of this structure have been examined in three orthogonal orientations under the compressive load. Detailed comparison and description were carried out on deformation mechanisms and failure modes in different lattice orientations. Finite element models using both beam elements and three-dimensional solid elements were used to simulate the compressive response of this structure. Both the load reaction and collapse modes obtained in simulations were compared with test results. Our results indicate that three-dimensional continuum element models are required to accurately capture the behaviour of real trusses, taking into account the effects of finite-sized beams and joints.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1021
Author(s):  
Yunzhao Li ◽  
Huaping Tang ◽  
Ruilin Lai

Resistance spot welded 1.2 mm (t)-thick 1400 MPa martensitic steel (MS1400) samples are fabricated and their microstructure, mechanical properties are investigated thoroughly. The mechanical performance and failure modes exhibit a strong dependence on weld-nugget size. The pull-out failure mode for MS1400 steel resistance spot welds does not follow the conventional weld-nugget size recommendation criteria of 4t0.5. Significant softening was observed due to dual phase microstructure of ferrite and martensite in the inter-critical heat affected zone (HAZ) and tempered martensite (TM) structure in sub-critical HAZ. However, the upper-critical HAZ exhibits obvious higher hardness than the nugget zone (NZ). In addition, the mechanical properties show that the cross-tension strength (CTS) is about one quarter of the tension-shear strength (TSS) of MS1400 weld joints, whilst the absorbed energy of cross-tension and tension-shear are almost identical.


2021 ◽  
Vol 16 (2-3) ◽  
pp. 61-74
Author(s):  
Sahar Ghasemi ◽  
Amir Mirmiran ◽  
Yulin Xiao ◽  
Kevin Mackie

A super lightweight deck can enhance load rating and functionality of a bridge, especially those identified as structurally deficient. This study was aimed to develop and experimentally validate a novel bridge deck as an ultra-lightweight low-profile waffle slab of ultra-high-performance concrete (UHPC) with either carbon fiber reinforced polymer (CFRP) or high strength steel (HSS) reinforcement. The proposed system lends itself to accelerated bridge construction, rapid deck replacement in bridges with load restrictions, and bridge widening applications without the need to replace girders. Performance and failure modes of the proposed deck were initially assessed through extensive lab experiments and finite element analysis, which together confirmed that the proposed deck panel meets the AASHTO LRFD requirements. The proposed deck system is not susceptible to punching shear of its thin slab and fails in a rather ductile manner. To evaluate its long-term performance, the system was further tested under the dynamic impact of wheel load at the Accelerated Pavement Testing (APT) facility of the Florida Department of Transportation using a Heavy Vehicle Simulator (HVS).


2011 ◽  
Vol 22 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Huigang Xiao ◽  
Hui Li ◽  
Jinping Ou

Cement-based strain sensors (CBCC sensor) were fabricated by taking the advantage of piezoresistivity of CB-filled CBCC. CBCC sensors were centrally embedded into concrete columns (made with C40 and C80 concretes, respectively) to monitor the strain of the columns under cyclic load and monotonic load by measuring the resistance of CBCC sensors. The comparison between the monitored results of CBCC sensors and that of traditional displacement transducers indicates that CBCC sensors have good strain-sensing abilities. Meanwhile, CBCC sensors exhibit different failure modes that break later than C40 concrete columns, but a little earlier than C80 concrete columns. Therefore, the strength-matching principle between embedded CBCC sensors and concrete columns is proposed in this article to guarantee the sensing capacity of CBCC sensors in various concrete structures. The analytical results agree well with the experimental phenomena.


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