Response of a Novel Beam-to-Column/Brace-to-Frame Connection to Monotonic and Cyclic Shear Loading

2008 ◽  
Author(s):  
S. V. Khonsari ◽  
G. L. England ◽  
F. Abazarsa
Keyword(s):  
Shear Deformation ◽  
Hysteresis Loops ◽  
Shear Stiffness ◽  
Shear Loading ◽  
Deformation Capacity ◽  
Braced Frame ◽  
Cyclic Shear ◽  
Column Joint ◽  
Structural Connections ◽  
Very High

A new universal structural joint was developed. While in bending it has a high rotational capacity, which can be accompanied by large bending stiffness and strength, in shear, it also has a very high shear deformation capacity, which can again be accompanied with large shear stiffness and strength. While the former characteristic makes it a good candidate for being used as a beam-to-column joint, the latter makes it highly applicable in connecting braces of a braced frame to the frame members. The experimental study carried out previously on this joint, concentrated on the performance of its steel specimens under ‘monotonic’ shear loading as well as that of its aluminium specimens under both ‘monotonic’ and ‘cyclic’ shear loading. The current study, however, comprises the experimental investigation into the behaviour of the mild steel specimens of this joint under ‘monotonic’ and ‘cyclic’ shear loading. As expected, the monotonic shear loading of the specimens of this new joint resulted in great amount of shear deformation, in contrary to basically all currently-used structural connections which lack any appreciable shear deformation capacity. Moreover, the specimens tested under cyclic shear loading also performed very well. The hysteresis loops of these specimens were ‘stable’ and ‘well-rounded’, implying large amount of energy dissipation in each cycle. Such very ductile response of the connections in shear is expected to be exploited in various circumstances in offshore as well as onshore structures to result in a ductile overall behavior of the structure.

Behaviour of an Innovative Universal Structural Connection Under Monotonic and Cyclic Shear Loading

2009 ◽  
Author(s):  
S. V. Khonsari ◽  
G. L. England ◽  
A. R. Mohammadi
Keyword(s):  
Shear Deformation ◽  
Shear Loading ◽  
Deformation Capacity ◽  
High Shear ◽  
Cyclic Tests ◽  
Shear Tests ◽  
Efficient Manner ◽  
Cyclic Shear ◽  
Structural Connection ◽  
Very High

A new structural connection with special unique features was developed. While under bending it showed very high rotational capacity, in shear, unlike other existing connections, it also demonstrated a large shear deformation capacity. The ductile response of this connection stems from its innovative geometry as well as the ductility of the elements embedded in it. Since the previous shear tests on the specimens of this connection were carried out under ‘unrestricted’ conditions, the tests reported here were all under ‘restricted’ conditions. These shear tests consisted of ‘monotonic’ as well as ‘cyclic’ tests on mild steel specimens. Due to the restrictions imposed on the specimens during the test, the stiffness increased, compared with that of their unrestricted counterparts. Also, the transition from shear phase to tensile phase of deformation took place at an earlier stage compared with its non-restricted counterpart. The monotonic tests proved the high shear deformation capacity of the connection which exists alongside its high stiffness as well as strength. The cyclic tests, however, showed the large number of hysteresis cycles the specimens could endure before failure. Both types of tests, monotonic and cyclic, proved the ability of the connection to dissipate energy in shear under either loading regime in a very efficient manner.

Application of Aluminium Alloys in a Structural Joint With Great Shear Deformation Capacity

2006 ◽  
Author(s):  
S. V. Khonsari ◽  
G. L. England ◽  
M. Ghahramaninezhad-Gharehlar
Keyword(s):  
Shear Deformation ◽  
Aluminium Alloys ◽  
High Energy ◽  
Shear Loading ◽  
Deformation Capacity ◽  
High Shear ◽  
Energy Dissipation Capacity ◽  
Structural Connection ◽  
High Energy Dissipation ◽  
Very High

A new structural connection, already discussed in previous papers, with very special and, in some respects, unique, features, such as having very high rotational capacity in bending, and high shear deformation capacity under shear, hence high energy-dissipation capacity under either type of loading, was developed. Specimens of either variant of this joint, fabricated with steel components, were already tested under bending and shear in a mainly separate manner. However, due to the particular shape of the connection, and its ability to be extruded in aluminium, in the most recent work the behaviour of its aluminium specimens under shear loading was studied. A series of specimens fabricated from various classes of aluminium alloys were tested whose results are reported here. All of the specimens except one were tested under ‘monotonic’ loading, and one specimen was tested ‘cyclically.’ Despite the deficiencies in the specimens caused by poor welding of their components, the results show the high shear deformation capacity of the aluminium specimens which was accompanied by appreciable strength.

Response of a Novel Beam-to-Column Connection to Monotonic and Cyclic Flexural Loading

2008 ◽  
Author(s):  
S. V. Khonsari ◽  
G. L. England ◽  
M. Shahsavar-Gargari ◽  
S. M. H. Parvinnia
Keyword(s):  
Hysteresis Loops ◽  
Offshore Platforms ◽  
Deformation Capacity ◽  
Bending Tests ◽  
Flexural Loading ◽  
Shear Performance ◽  
Column Joint ◽  
Number Of Cycles ◽  
The Cost ◽  
Non Destructive

A new beam-to-column joint with high rotational as well as shear deformation capacity was devised. This high rotational ‘capacity’ is required to fulfill the great ‘demand’ for rotation arising during earthquakes, severe waves and current loads, etc. Due to its ability to contain damage during an overload, it leaves the connected elements intact. This, together with its replaceability can reduce the cost of post-event repair substantially. Its bending as well as shear performance under “monotonic” loading had already been assessed experimentally (OMAE’02-28864, OMAE’03-37292, OMAE’04-51494 & OMAE’05-67361) and proved well superior to that of conventional joints. In order to study its performance under “cyclic” flexural loading experimentally, new bending tests were conducted on mild steel specimens of the connection. These tests clearly showed the ability of the devised joint to withstand adequate number of cycles in bending and dissipate energy through well-shaped hysteresis loops. This would result in large amount of energy being dissipated in each cycle. Such very ductile response of this connection in bending is expected to be exploited in various circumstances in offshore as well as onshore structures to give rise to a ductile overall behavior of the structure. In particular, it can be utilized for the repair and retrofitting of the aging offshore platforms which need to be treated in a non-destructive manner.

Horizontal Connections for Precast Concrete Shear Wall Panels Under Cyclic Shear Loading

PCI Journal ◽  
1996 ◽  
Vol 41 (3) ◽  
pp. 64-80 ◽  
Author(s):  
Khaled A. Soudki ◽  
Jeffrey S. West ◽  
Sami H. Rizkalla ◽  
Bruce Blackett
Keyword(s):  
Precast Concrete ◽  
Shear Wall ◽  
Shear Loading ◽  
Cyclic Shear ◽  
Horizontal Connections ◽  
Wall Panels

Deformation Characteristics of Reinforced Concrete Beam-Column Joint Cores under Earthquake Loading

2003 ◽  
Vol 6 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Sayed A. Attaalla ◽  
Mehran Agbabian
Keyword(s):  
Reinforced Concrete ◽  
Shear Deformation ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Frame ◽  
Bond Failure ◽  
Strain Compatibility ◽  
Concrete Frame ◽  
Column Joint ◽  
Reinforced Concrete Frame Structures

The characteristics of the shear deformation inside the beam-column joint core of reinforced concrete frame structures subjected to seismic loading are discussed in this paper. The paper presents the formulation of an analytical model based on experimental observations. The model is intended to predict the expansions of beam-column joint core in the horizontal and vertical directions. The model describes the strain compatibility inside the joint in an average sense. Its predictions are verified utilizing experimental measurements obtained from tests conducted on beam-column connections. The model is found to adequately predict the components of shear deformation in the joint core and satisfactorily estimates the average strains in the joint hoops up to bond failure. The model may be considered as a simple, yet, important step towards analytical understanding of the sophisticated shear mechanism inside the joint and may be implemented in a controlled-deformation design technique of the joint.

Stress–strain pattern–based criterion to assess cyclic shear resistance of soil from laboratory element tests

2016 ◽  
Vol 53 (9) ◽  
pp. 1460-1473 ◽  
Author(s):  
Dharma Wijewickreme ◽  
Achala Soysa
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Shear Stiffness ◽  
Large Strains ◽  
Fundamental Parameter ◽  
Stress Strain ◽  
Cyclic Shear ◽  
Excess Pore Water Pressure ◽  
Excess Pore

The cyclic shear response of soils is commonly examined using undrained (or constant-volume) laboratory element tests conducted using triaxial and direct simple shear (DSS) devices. The cyclic resistance ratio (CRR) from these tests is expressed in terms of the number of cycles of loading to reach unacceptable performance that is defined in terms of the attainment of a certain excess pore-water pressure and (or) strain level. While strain accumulation is generally commensurate with excess pore-water pressure, the definition of unacceptable performance in laboratory tests based purely on cyclic strain criteria is not robust. The shear stiffness is a more fundamental parameter in describing engineering performance than the excess pore-water pressure alone or shear strain alone; so far, no criterion has considered shear stiffness to determine CRR. Data from cyclic DSS tests indicate consistent differences inherent in the patterns between the stress–strain loops at initial and later stages of cyclic loading; instead of relatively “smooth” stress–strain loops in the initial parts of loading, nonsmooth changes in incremental stiffness showing “kinks” are notable in the stress–strain loops at large strains. The point of pattern change in a stress–strain loop provides a meaningful basis to determine the CRR (based on unacceptable performance) in cyclic shear tests.

Nonlinear FE analysis of precast RC pinned beam-to-column connections under monotonic and cyclic shear loading

2013 ◽  
Vol 12 (4) ◽  
pp. 1615-1638 ◽  
Author(s):  
Georgia D. Kremmyda ◽  
Yasin M. Fahjan ◽  
Spyros G. Tsoukantas
Keyword(s):  
Shear Loading ◽  
Fe Analysis ◽  
Cyclic Shear ◽  
Nonlinear Fe Analysis
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