scholarly journals Test Arrangement of Small-scale Shear Tests of Composite Slabs

2016 ◽  
Vol 161 ◽  
pp. 716-721 ◽  
Author(s):  
Josef Holomek ◽  
Miroslav Bajera ◽  
Martin Vilda
Keyword(s):  
Small Scale ◽  
Shear Tests ◽  
Composite Slabs ◽  
Scale Shear

Shear Tests of Composite Slabs, Experimental and Numerical Investigation

2014 ◽  
Vol 923 ◽  
pp. 217-220 ◽  
Author(s):  
Josef Holomek ◽  
Miroslav Bajer ◽  
Jan Barnat ◽  
Martin Vild
Keyword(s):  
Large Scale ◽  
Small Scale ◽  
Concrete Slabs ◽  
Shear Tests ◽  
Composite Action ◽  
Permanent Formwork ◽  
Composite Slabs ◽  
New Type ◽  
Large Scale Tests ◽  
Scale Shear

Composite slab is being used for horizontal structures. The sheeting can serve as a permanent formwork and no additional reinforcement can be required. The slabs are then fast and easy assemble construction which can be effectively used in reconstructions. One of the meanings to assure composite action of composite steel-concrete slabs is prepressed embossments. Its main disadvantage is that the design of a new type of sheeting requires expensive and time consuming large-scale laboratory testing which hamper its widespread commercial usage. Small-scale shear tests present a less expensive alternative to the large-scale tests but its results cannot be simply used for the design of the whole slab. The results from small-scale tests with different options are compared in this paper. Also a possibility of contribution of FE simulation results to the small-scale tests usage is investigated.

Longitudinal Shear Analysis of Composite Slabs with Prepressed Embossments

2015 ◽  
Vol 1122 ◽  
pp. 265-268
Author(s):  
Josef Holomek ◽  
Miroslav Bajer ◽  
Martin Vild
Keyword(s):  
Bearing Capacity ◽  
Design Method ◽  
Numerical Models ◽  
Longitudinal Shear ◽  
Small Scale ◽  
Shear Tests ◽  
Bending Tests ◽  
Load Bearing ◽  
Composite Slabs ◽  
Shear Bearing Capacity

Composite slabs with prepressed embossments present an effective solution for horizontal load bearing structures. Sheeting serves as a formwork in construction stage and as a tension bearing member after hardening of concrete. There is no need for additional tensile reinforcement in case of sufficient longitudinal shear bearing capacity of the embossments. Longitudinal shear bearing capacity is not precisely determined when designing according to nowadays standards. Full scale bending tests of the slabs are used to determine characteristics for m – k method or partial connection method. Bending tests are expensive and space demanding. Alternatively small-scale shear tests can be used to determine shear characteristics of the sheeting. However, shear tests cannot include all the effects affecting the bearing capacity of bended slab, such as effect of curvature or distribution of load. Therefore, related design method has to be used to determine load bearing capacity of the slab in bending. This paper extends achievements presented by the authors in contribution in CRRB 2013. The results of small-scale tests are compared with results of numerical models of the slab in shear. Numerical models are created in two different finite element codes. Setting of steel-concrete interface properties in the models is validated using data from literature.

Characteristics of small-scale shear layers in a temporally evolving turbulent planar jet

2021 ◽  
Vol 920 ◽  
Author(s):  
Masato Hayashi ◽  
Tomoaki Watanabe ◽  
Koji Nagata
Keyword(s):  
Shear Layers ◽  
Small Scale ◽  
Planar Jet ◽  
Scale Shear

Abstract

scholarly journals Small-scale shear effects on heterocystous cyanobacteria

2002 ◽  
Vol 47 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Pia H. Moisander ◽  
James L. Hench ◽  
Kaisa Kononen ◽  
Hans W. Paerl
Keyword(s):  
Small Scale ◽  
Heterocystous Cyanobacteria ◽  
Shear Effects ◽  
Scale Shear

Drift of Piles Subjected to Cyclic Lateral Loading From a Varying Direction: System vs. Soil Element Behavior

2014 ◽  
Author(s):  
Christina Rudolph ◽  
Jürgen Grabe ◽  
Britta Bienen
Keyword(s):  
Cyclic Loading ◽  
Model Tests ◽  
Small Scale ◽  
Shear Tests ◽  
Centrifuge Testing ◽  
Scale Modeling ◽  
Highly Sensitive ◽  
Number Of Cycles ◽  
Laterally Loaded ◽  
Insight Into

Offshore monopiles are usually designed using the p-y method for cyclic loading. While the method works for static loading, it was not developed for high numbers of cycles. Since the turbines are highly sensitive towards tilting, cyclic loading must be considered. The static results should therefore be combined with results from cyclic model tests with a high number of cycles to account for the accumulation of displacement or rotation during the lifetime of these structures. These model tests can underestimate the accumulation, however, as it has recently been shown that a change of loading direction can increase the accumulation considerably. These results have been verified using small scale modeling and centrifuge testing. The results from modeling the full problem of a laterally loaded pile are compared here with results from cyclic simple shear tests with a change of shearing direction during the cyclic loading. For these tests, a newly developed apparatus is used. This allows further insight into the question how a soil can “retain a memory” of its loading history.

scholarly journals Using Post-Harvest Waste to Improve Shearing Behaviour of Loess and Its Validation by Multiscale Direct Shear Tests

2019 ◽  
Vol 9 (23) ◽  
pp. 5206 ◽  
Author(s):  
Wen-Chieh Cheng ◽  
Zhong-Fei Xue ◽  
Lin Wang ◽  
Jian Xu
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Strain Hardening ◽  
Gradual Increase ◽  
Small Scale ◽  
Optimal Dosage ◽  
Direct Shear ◽  
Shear Tests ◽  
Post Harvest ◽  
Direct Shear Tests

Loess and PHW (post-harvest waste) are easily accessible in the Chinese Loess Plateau and have been widely applied to construction of residential houses that have been inhabited for decades under the effect of freeze-thaw cycles. Although many researchers have recognised that the addition of fibers to loess soil is effective in preventing soil erosion and stabilising slopes, a consensus on this claim has not been reached yet. This study investigates the shearing behaviour of the loess-PHW mixture using small-scale and large-scale direct shear (SSDS and LSDS) tests. Four typical shear stress versus horizontal displacement curves from the multiscale direct shear tests are recognised where one is featured with strain-softening shape and the other three with a strain-hardening shape. Two out of the three curves with strain-hardening shape show a gradual increase in the shear stress at additional and larger displacements, respectively, in which some factor starts to have an influence on the shearing behaviour. Comparisons of the shear strength measured in SSDS and LSDS are made, indicating that there are differences between SSDS and LSDS. The effect of PHW addition on shear strength is assessed in order to determine the optimal dosage. The improvement of shear strength is attributed to the effect of particle inter-locking, resulting from the addition of PHW to loess specimens, and takes effect as the water content surpassed a threshold, i.e., >14%, that facilitates particle rearrangement. Particle-box interaction behaviour is assessed at the same time, and the findings satisfactorily address the main cause of the gradual increase in shear stress following the curve inflection point. The improved shearing behaviour proves the ability of the loess-PHW mixture to resist the seepage force and consequently stratum erosion.

scholarly journals Tensile Tests for the Improvement of Adhesion between Rubber and Steel Layers in Elastomeric Isolators

2020 ◽  
Vol 10 (22) ◽  
pp. 8063
Author(s):  
Margherita Pauletta ◽  
Federico Pinzano ◽  
Giada Frappa ◽  
Gaetano Russo
Keyword(s):  
Manufacturing Process ◽  
Seismic Isolation ◽  
Tensile Tests ◽  
Small Scale ◽  
Shear Tests ◽  
Good Adhesion ◽  
Single Body ◽  
Adhesion Behavior ◽  
Shear Strains ◽  
Direct Tensile

Steel reinforced elastomeric isolators are currently the most used bearings for seismic isolation purposes. The steel reinforcements are cut to the desired shape, sandblasted, cleaned with acid, and coated with bonding compound during the manufacturing process. Then the elastomer and steel layers are stacked in a mold and subjected to vulcanization so that they are glued together and constitute a single body. Good adhesion between the layers is very important for the correct functioning of the device. Adhesion conditions become critical when the isolators are subjected to tensile stresses, which arise under direct tensile actions or large shear strains. To analyze the influence of changes in the manufacturing process on the isolator adhesive behavior, the authors performed tensile tests on square-shaped small-scale specimens rather than expensive shear tests on full-scale isolators. Hence, the adhesion behavior between elastomer and steel layers was investigated through the tensile tests discussed herein. Among the influencing parameters that were considered, it was found that an increase in vulcanization time does not improve the adhesion, but it may actually worsen the capacity of the isolator in terms of strength. Moreover, it was found that using elastomer without an oily component improves the adhesion between the layers and increases the isolator’s dissipative capacity.

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