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/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.

Identification of the anisotropic behavior of an aluminum alloy subjected to simple and cyclic shear tests

2018 ◽  
Vol 233 (3) ◽  
pp. 911-927 ◽  
Author(s):  
Daghfas Olfa ◽  
Znaidi Amna ◽  
Gahbiche Amen ◽  
Nasri Rachid
Keyword(s):  
Aluminum Alloy ◽  
Kinematic Hardening ◽  
Plastic Anisotropy ◽  
Mechanical Tests ◽  
Material Behavior ◽  
Isotropic Hardening ◽  
Cyclic Tests ◽  
Shear Tests ◽  
2024 Aluminum Alloy ◽  
Cyclic Shear

The main purpose of this paper is to study the behavior of the 2000 aluminum alloy series used particularly in the design of Airbus fuselage. The characterization of the mechanical behavior of sheet metal on 2024 aluminum alloy and its response to various loading directions under monotonic and cyclic tests are extremely considered. To solve this problem, first, an experimental platform which essentially revolves around mechanical tests and then a series of optical and transmission electronic visualizations have been carried out. These mechanical tests are monotonic and cyclic shear tests applied under the same conditions on the test specimens of 2024 aluminum alloy. Cyclic shear tests have been carried out in order to show the Bauschinger effect and then the kinematic hardening phenomenon. The hardening curves of the simple shear test showed the Portevin-Le Chatelier effect for all loading directions. Next, the experimental results obtained (Portevin-Le Chatelier and Bauschinger effects) are discussed and analyzed in relation to the microstructure of the studied alloy using an optical microscope and a transmission electron microscope. Thereafter, the plastic anisotropy is modeled using an identification strategy that depends on a plastic criterion, an isotropic hardening law, a kinematic hardening (linear and nonlinear) law, and an evolution law. More precisely, particular attention is paid to the isotropic power Hollomon law, the saturation Voce law, and the saturation Bron law. In the case of the cyclic tests, linear kinematic hardening described by the Prager law and nonlinear kinematic hardening expressed by the Armstrong–Frederick law are introduced. Finally, by smoothing the experimental hardening curves for the various simple and cyclic shear tests, a selection is made in order to choose the most appropriate law for the identification of the material behavior.

scholarly journals Experimental Study on Shear Stress-Displacement, Creep and Shear Slip Instability Behavior of Rock Fractures

2021 ◽  
Author(s):  
Minglei Zhai ◽  
Haibo Bai
Keyword(s):  
Shear Stress ◽  
Rock Mass ◽  
Shear Loading ◽  
Shear Displacement ◽  
Rock Fractures ◽  
Shear Tests ◽  
Creep Tests ◽  
Shear Creep ◽  
Cyclic Shear ◽  
Multistage Loading

Abstract Rock mass inherently contains discontinuities, and shear sliding of rock masses along discontinuities is the most common failure mode of rock mass in engineering practice (such as slope, dam and tunnel). In this study, the mechanical and failure properties of rock fractures were examined through direct shear tests, pre-peak tiered cyclic shear tests and multistage loading shear creep tests. The results show that the deformable memory of rocks can be observed from shear stress-shear displacement curves, namely reloading curves continued to increase along the loading curve of the last cycle under the pre-peak tiered cyclic shear loading. The envelopes of shear stress-shear displacement curves were similar to the variation trend of shear stress-shear displacement curves obtained in the direct shear test. Besides, the variation trend of residual shear displacement (RSD) and relative residual shear displacement (RRSD) before slip instability were obtained by the data analyses of rock mass under pre-peak tiered cyclic shear tests. It is found that the change in the friction and sliding state of rock fracture is the main reason for the fluctuation of shear stress-shear displacement curves. The Chen's method was used to process the multistage loading shear creep curves and the three creep stages were analyzed. Moreover, the complex creep models in some previous studies were discussed and the data of shear creep tests were successfully fitted to the classical Burgers model. This study provides a guidance for the study on the shear instability of rock fractures under different shear loading paths.

scholarly journals Anchorage strength and ductility in shear tests

2021 ◽  
Vol 263 ◽  
pp. 02016
Author(s):  
Aleksandr Shuvalov ◽  
Igor Gorbunov ◽  
Mikhail Kovalev
Keyword(s):  
Cyclic Loading ◽  
Shear Loading ◽  
Seismic Loads ◽  
Cyclic Tests ◽  
Shear Tests ◽  
Cracked Concrete ◽  
Loading Pattern ◽  
Shear Loads ◽  
Loading Tests ◽  
Strength And Ductility

Article shows shear tests results for anchorage using bent foundation bolts 16, 24 and 36 mm in diameter and torque-controlled undercut anchors 12, 16 and 20 mm in diameter. Load-displacement diagrams were acquired for shear loads in static and dynamic cyclic tests in uncracked and cracked concrete. Cyclic loading pattern simulated seismic loads on anchors. Shear loading tests allowed to estimate influence of cracks and cyclic loading on strength and ductility of anchorage.

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

GpIbα-VWF blockade restores vessel patency by dissolving platelet aggregates formed under very high shear rate in mice

Blood ◽  
2014 ◽  
Vol 123 (21) ◽  
pp. 3354-3363 ◽  
Author(s):  
Audrey Le Behot ◽  
Maxime Gauberti ◽  
Sara Martinez De Lizarrondo ◽  
Axel Montagne ◽  
Eloïse Lemarchand ◽  
...  
Keyword(s):  
Shear Rate ◽  
Endothelial Damage ◽  
Cross Linking ◽  
High Shear ◽  
External Layer ◽  
Vessel Lumen ◽  
Key Points ◽  
Vessel Patency ◽  
Platelet Aggregates ◽  
Very High

Key Points Following endothelial damage, platelet cross-linking during closure of the vessel lumen is mediated by GpIbα-VWF interactions. Disruption of GpIbα-VWF interactions restores vessel patency by specifically disaggregating the external layer of occlusive thrombi.

scholarly journals Effect of local instability on fire response of steel beams

2017 ◽  
Vol 1 (2) ◽  
pp. 170-179 ◽  
Author(s):  
Venkatesh Kodur ◽  
Mohannad Z. Naser
Keyword(s):  
Shear Loading ◽  
Shear Capacity ◽  
Valuable Insight ◽  
High Shear ◽  
Local Instability ◽  
Steel Girders ◽  
Fire Response ◽  
Limit States ◽  
Flexural Mode ◽  
Content Type

Purpose This purpose of this paper is to quantify the effect of local instability arising from high shear loading on response of steel girders subjected to fire conditions. Design/methodology/approach A three-dimensional nonlinear finite element model able to evaluate behavior of fire-exposed steel girders is developed. This model, is capable of predicting fire response of steel girders taking into consideration flexural, shear and deflection limit states. Findings Results obtained from numerical studies show that shear capacity can degrade at a higher pace than flexural capacity under certain loading scenarios, and hence, failure can result from shear effects prior to attaining failure in flexural mode. Originality/value The developed model is unique and provides valuable insight (and information) to the fire response of typical hot-rolled steel girder subjected to high shear loading.

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