Experimental tests of different types of bolted steel beam–column joints under a central-column-removal scenario

2013 ◽  
Vol 54 ◽  
pp. 112-130 ◽  
Author(s):  
Bo Yang ◽  
Kang Hai Tan
Keyword(s):  
Experimental Tests ◽  
Steel Beam ◽  
Column Removal ◽  
Different Types ◽  
Central Column ◽  
Column Removal Scenario

Behaviour of Different Types of Steel Connections in Steel Frames against Progressive Collapse

2011 ◽  
Vol 374-377 ◽  
pp. 1330-1341
Author(s):  
Kang Hai Tan ◽  
Bo Yang
Keyword(s):  
Parametric Study ◽  
Progressive Collapse ◽  
Experimental Tests ◽  
Test Results ◽  
Large Rotation ◽  
Catenary Action ◽  
Column Removal ◽  
Different Types ◽  
Column Removal Scenario ◽  
Middle Column

Firstly, this paper presents an overview of DoD code [1] against progressive collapse and points out the shortcomings of the current design approaches. After that, seven experimental tests of common types of bolted steel beam-column joints under a middle-column removal scenario are presented. This study provides the behaviour and failure modes of different types of connections, including their resistances and rotational capacities in catenary action. The test results indicate that the web cleat connection has the best performance in the development of catenary action. The flush end plate, fin plate and top and seat with web angle (TSWA) connections could also deform in a ductile manner and develop catenary action prior to failure. Numerical simulations have also been conducted. Both static and explicit dynamic solvers were employed to overcome problems of non-convergence, contact, large deformation and fracture simulations. It is demonstrated that the finite element analyses give reasonable accuracy compared to the test results. In addition, an extensive parametric study was undertaken using these validated models to obtain the rotation capacities of various types of connections under catenary action. Finally, some practical design implications have been drawn up from the experimental tests and the parametric study. A new tying resistance expression is proposed to consider the effect of large rotation. If large rotation capacity is not considered in the design stage, the joints with poor rotation capacities would fail to achieve the design tying resistances. In addition, four new connection acceptance criteria of rotation capacities have been proposed to incorporate catenary action under a middle column removal scenario. The work shows that current acceptance criteria of rotation capacities for steel joints such as web cleat, fin plate, flush end plate and TSWA connections, are probably too conservative as they only consider pure flexural resistance.

scholarly journals Progressive Collapse Performance of Steel Beam-to-Column Connections: Critical Review of Experimental Results

2021 ◽  
Vol 15 (1) ◽  
pp. 152-163
Author(s):  
Massimiliano Ferraioli
Keyword(s):  
Axial Force ◽  
Critical Review ◽  
Progressive Collapse ◽  
Tensile Force ◽  
Experimental Results ◽  
Steel Beam ◽  
Rotation Capacity ◽  
Column Removal ◽  
Different Types ◽  
Plastic Rotation Capacity

Background: The steel beam-to-column connections are vulnerable structural elements when a building loses one or more of its vertical load-carrying components due to abnormal or accidental loading conditions. After a column is destroyed by abnormal loads, the tensile axial force of the beam gradually increased, while the bending moment decreased, and the load-resistance mechanism shifts from a flexural mechanism to a catenary mechanism, with the axial force becoming the prevailing factor. Aims: This paper investigates the progressive collapse performance of steel beam-to-column connections. While undergoing large deformation, the beam-to-column connections are subjected to moment, shear, and tension in conjunction with high ductility demand. Their behavior under monotonic loading depends on the moment-axial tension interaction and greatly affects the progressive collapse resistance of the structure. This paper presents a critical review of experimental tests of different types of steel beam-column joints (flexible, rigid, and semi-rigid) under a central-column-removal scenario. Methods: The experimental results, including load-deformation relationships, failure modes, and catenary effects, are described in detail. The findings are used to evaluate the rotation capacity of different types of steel beam-to-column connections. The results are compared to the acceptance criteria specified by the main progressive collapse guidelines for several beam-to-column connection categories. Results: In simple (flexible) joints, the stiffness and strength at higher drift angles essentially depend on the tensile capacity of the connection that prevents, in some cases, the full development of the catenary mechanism. The connection depth alone does not seem to be an effective parameter to predict the rotational capacity of beam-to-column connections, since different connections with similar values of the connection depth result in very different values of the maximum rotation capacity. In fully rigid and semi-rigid connections, after the column removal, the flexural resistance controls the behavior at the preliminary phase, and the tensile force is almost zero. With increased downward displacement, the axial tensile force also increases, developing a catenary mechanism. Although the stiffness of rigid and semi-rigid connections is higher than flexible connections, both categories result in similar rotation capacity. Conclusion: In all the simple connections herein considered, the plastic rotation capacity obtained by tests was found much higher than the code recommended values that are probably too conservative. On the contrary, for one rigid and two semi-rigid connections, the values of the plastic rotation capacity obtained by tests are lower than the corresponding recommended values. Thus, the suggested acceptance criteria proved to be out of the conservative side.

scholarly journals Numerical Evaluation of a Light-Gas Gun Facility for Impact Test

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
C. Rahner ◽  
H. A. Al-Qureshi ◽  
D. Stainer ◽  
D. Hotza ◽  
M. C. Fredel
Keyword(s):  
High Velocity ◽  
Numerical Evaluation ◽  
Impact Test ◽  
Experimental Tests ◽  
Reservoir Pressure ◽  
One Stage ◽  
Gas Gun ◽  
Numerical Predictions ◽  
High Velocity Impacts ◽  
Different Types

Experimental tests which match the application conditions might be used to properly evaluate materials for specific applications. High velocity impacts can be simulated using light-gas gun facilities, which come in different types and complexities. In this work different setups for a one-stage light-gas gun facility have been numerically analyzed in order to evaluate their suitability for testing materials and composites used as armor protection. A maximal barrel length of 6 m and a maximal reservoir pressure of a standard industrial gas bottle (20 MPa) were chosen as limitations. The numerical predictions show that it is not possible to accelerate the projectile directly to the desired velocity with nitrogen, helium, or hydrogen as propellant gas. When using a sabot corresponding to a higher bore diameter, the necessary velocity is achievable with helium and hydrogen gases.

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