Direct Shear Behavior of Planar Joints Under Cyclic Normal Load Conditions: Effect of Different Cyclic Normal Force Amplitudes

2017 ◽  
Vol 50 (11) ◽  
pp. 3101-3107 ◽  
Author(s):  
Wengang Dang ◽  
Heinz Konietzky ◽  
Thomas Frühwirt
Keyword(s):  
Normal Force ◽  
Normal Load ◽  
Shear Behavior ◽  
Direct Shear ◽  
Load Conditions

Application of acoustic emission for monitoring shear behavior of bonded concrete–rock joints under direct shear test

2012 ◽  
Vol 39 (8) ◽  
pp. 887-896 ◽  
Author(s):  
Z.A. Moradian ◽  
G. Ballivy ◽  
P. Rivard
Keyword(s):  
Acoustic Emission ◽  
Shear Strength ◽  
Normal Load ◽  
Adhesive Bond ◽  
Shear Behavior ◽  
Displacement Rate ◽  
Bond Breaking ◽  
Bonded Joints ◽  
Direct Shear ◽  
Shear Process

Studying shear behavior and failure mechanism of concrete–rock interfaces between concrete structures and rock mass is highly important. To this end, laboratory direct shear tests were conducted on several bonded interfaces. The effect of normal stress, displacement rate, and bonding percentage on shear behavior of bonded joints were also evaluated. The results showed that the adhesive bond between concrete and rock has the most important effect on shear mechanism of concrete–rock interfaces. When the normal load is low, the asperities do not contribute in shear process, so the shear strength of the joints is governed by adhesive bond. The only contribution of the asperities is that they show a small peak after bond breaking peak. When the normal load is high, the asperities break simultaneously with adhesive bond and they show their contribution in the whole shear process. In a constant normal load, by decreasing bonding percentage, the brittle failure of the bonded joints is changed into softening failure because of less contribution of the adhesive bond and more contribution of the rough asperities in joint failure. Acoustic emission (AE) monitoring of bonded joints showed that for all different tested samples under various loading conditions, there has been no or very few AE activities before adhesive bond breaking point, indicating that other parameters (roughness, normal load, displacement rate) are impressed by adhesive bond and maximum shear strength is determined by this parameter.

Direct shear behavior of a plane joint under dynamic normal load (DNL) conditions

2016 ◽  
Vol 213 ◽  
pp. 133-141 ◽  
Author(s):  
Wengang Dang ◽  
Heinz Konietzky ◽  
Thomas Frühwirt
Keyword(s):  
Normal Load ◽  
Shear Behavior ◽  
Direct Shear ◽  
Plane Joint

scholarly journals Role of capillary adhesion in the friction peak during the tacky transition

Friction ◽  
2021 ◽  
Author(s):  
Tianyan Gao ◽  
Jiaxin Ye ◽  
Kaisen Zhang ◽  
Xiaojun Liu ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Indentation Depth ◽  
Normal Force ◽  
Normal Load ◽  
Pdms Film ◽  
Capillary Adhesion ◽  
Static Contact ◽  
Van Der Waals Attraction ◽  
Contact Experiments

AbstractThe friction peak that occurs in tire-road sliding when the contact changes from wet to dry was previously attributed to capillary cohesion, van der Waals attraction, and surface roughness, but the detailed mechanisms have yet to be revealed. In this study, friction and static contact experiments were conducted using a custom-built in situ optical microtribometer, which allowed us to investigate the evolution of the friction, normal load, and contact area between a polydimethylsiloxane (PDMS) film and a silicon nitride ball during water volatilization. The friction coefficient increased by 100%, and the normal force dropped by 30% relative to those in the dry condition during the wet-to-dry transition. In static contact experiments, the probe indentation depth increased, and the normal load decreased by ∼60% as the water evaporated. Combining the friction and static contact results, we propose that the large friction peak that appeared in this study can be attributed to the combined effects of increased adhesive capillary force and increased plowing during the wet-to-dry transition.

Direct and Flexural Shear Strength of Composite Beam with Perforbond Rib

2018 ◽  
Vol 26 (1) ◽  
pp. 9-18
Author(s):  
Dooyong Cho ◽  
Jinwoong Choi ◽  
Hoseong Jeong
Keyword(s):  
Shear Stress ◽  
Shear Test ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Flexural Behavior ◽  
Direct Shear ◽  
Test Results ◽  
Shear Connectors ◽  
The Difference ◽  
Push Out

When Perfobond Rib shear connectors are used as flexural materials in structures such as bridges, they show flexural shear behavior due to external force, rather than direct shear behavior. The aim of this study is thus to analyze the difference between both behaviors. First, we prepared a specimen to analyze direct shear behavior using Perfobond Rib shear connectors, analyzed the characteristics of behavior with a push-out test and proposed a formula of shear resistance assessment. Proposed formula shows a relatively good fit with less than 10% error. A flexural shear test was then conducted based on the result of the direct shear test. Based on the static flexural test it analyzed the flexural behavior and the flexural shear stress it calculated. Direct shear stress and EN 1994-1-1 to lead and be calculated, it compared the flexural shear stress and it analyzed in about the shear resistance stress which it follows in load direction. Finally, we compared both test results, and the comparison showed that the flexural shear stress is approximately 6% stronger than the direct shear stress.

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