scholarly journals Experimental Investigations of Concrete Filled Battened Steel Columns of Different Slenderness

2019 ◽  
Vol 65 (4) ◽  
pp. 3-19
Author(s):  
M. Siennicki
Keyword(s):  
Carrying Capacity ◽  
Concrete Columns ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Design Standards ◽  
Steel Columns ◽  
Load Carrying ◽  
Bare Steel ◽  
Concrete Filling ◽  
Full Scale Tests

AbstractThe study investigates the axial load behaviour of concrete filled battened steel columns not covered by the design standards. A series of full scale tests on two I-sections connected together with intermediate batten plates and filled with concrete were carried out. The main parameters varied in the tests are length of the members and strength of the concrete filling. One bare steel member was also tested and results were compared with those filled with concrete. The tests results were illustrated by load-strain curves. The main objectives of these tests were twofold: first, to describe behaviour of new steel-concrete columns and second, to analyze the influence of slenderness on load-carrying capacity.

scholarly journals INFLUENCE OF CONCRETE AND FIBRE CONCRETE ON THE LOAD‐CARRYING CAPACITY AND DEFORMABILITY OF COMPOSITE STEEL‐CONCRETE COLUMNS

2007 ◽  
Vol 13 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Elżbieta Szmigiera
Keyword(s):  
Carrying Capacity ◽  
Load Capacity ◽  
Concrete Columns ◽  
Considerable Effect ◽  
Load Carrying Capacity ◽  
Steel Columns ◽  
Fibre Concrete ◽  
Load Carrying ◽  
Increasing Load ◽  
Composite Steel

The report presents the results of laboratories’ tests on steel columns strengthened by concrete casing. During testing of steel I‐shape column the strength of concrete casing and the way of the column loading were parameters subjected to changes. The possibility of increasing load capacity of columns by strengthening the supporting zones was checked, too. On the basis of tests performed, it has been stated that there is a considerable effect of concrete casing on the performance and capacity of steel columns. Possibility of increasing the load capacity of columns by making heads of fibre concrete has been shown.

Experimental Study on Mechanical Properties of Axially Loaded PVC Tubed Short Concrete Columns

2011 ◽  
Vol 99-100 ◽  
pp. 715-718 ◽  
Author(s):  
Jun Dong ◽  
De Ping Chen ◽  
Ju Mei Zhao ◽  
De Shan Shan ◽  
Xin Yue Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carrying Capacity ◽  
Loading Condition ◽  
Concrete Strength ◽  
Concrete Columns ◽  
Load Carrying Capacity ◽  
Composite Columns ◽  
Load Carrying ◽  
Strength And Deformation ◽  
Axially Loaded

Twelve PVC tubed short concrete columns and four columns without PVC tube confined were tested under axial load to investigate mechanical properties of axially loaded PVC tubed short concrete columns . The principal influencing factors such as concrete strength, loading condition and ratio of height to diameter were studied. Test results indicated that strength and deformation performance of core concrete increased as a result of the confinement of PVC tube. The PVC tube confinement effect on concrete will decrease with an increase in strength of concrete. Load- carrying capacity and deformation of short composite columns with different loading condition made some difference. As the ratio of height to diameter increases, load- carrying capacity and plasticity of short composite columns decreased gradually.

Influence of tribofilms on failures and friction of gears with particular focus on running-in

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Andreas Ziegltrum ◽  
Stefan Emrich ◽  
Thomas Lohner ◽  
Klaus Michaelis ◽  
Alexander Brodyanski ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Carrying Capacity ◽  
Experimental Investigations ◽  
Spur Gears ◽  
Load Carrying Capacity ◽  
Friction Behavior ◽  
Content Type ◽  
Load Carrying ◽  
Gear Contact ◽  
Local Pressures

Purpose This paper aims to address the influence of tribofilms and running-in on failures and friction of gears. The operation regime of gears is increasingly shifted to mixed and boundary lubrication, where high local pressures and temperatures occur at solid interactions in the gear contact. This results in strong tribofilm formation due to interactions of lubricant and its additives with the gear flanks and is related to changes of surface topography especially pronounced during running-in. Design/methodology/approach Experiments at a twin-disk and gear test rig were combined with chemical, structural and mechanical tribofilm characterization by surface analysis. Pitting lifetime, scuffing load carrying capacity and friction of ground spur gears were investigated for a mineral oil with different additives. Findings Experimental investigations showed a superordinate influence of tribofilms over surface roughness changes on damage and friction behavior of gears. Surface analysis of tribofilms provides explanatory approaches for friction behavior and load carrying capacity. A recommendation for the running-in of spur gears was derived. Originality/value Experimental methods and modern surface analysis were combined to study the influence of running-in and tribofilms on different failures and friction of spur gears.

scholarly journals Influence of ties on the behavior of short reinforced concrete columns strengthened by external CFRP

2018 ◽  
Vol 162 ◽  
pp. 04005
Author(s):  
Kaiss Sarsam ◽  
Raid Khalel ◽  
Mohammed Hadi
Keyword(s):  
Carrying Capacity ◽  
Concrete Columns ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
The Difference ◽  
Normal Strength

An experimental study was carried out to investigate the behavior of normal strength reinforce concret (RC) circular short column strengthned with “carbon fiber reinforced polymer (CFRP) sheets”. Three series comprising totally of (15) specimens loaded until failure under concentric compresion load. Strengthening was varied by changing the number of CFRP strips, spacing and wrapping methods. The findings of this research can be summarized as follows: for the columns without CFRP, the influence of the tie spacing was significant: compared with 130 mm tie spacing, dropping the spacing to 100 mm and 70 mm increased the load carrying capacity by 18% and 26%, respectively. The columns with less internal confinement (lesser amount of ties) were strengthened more significantly by the CFRP than the ones with greater amount of internal ties. As an example of the varying effectiveness of the fully wrapped CFRP, the column with ties at 130 mm was strengthened by 90% with the CFRP. In contrast, the ones with 70 mm spaced ties only increased in strength with CFRP by 66%. Compared with the control specimen (no CFRP), the same amount of CFRP when used as hoop strips led to more strengthening than using CFRP as a spiral strip- the former led to nearly 9% more strengthening than the latter in the case of 130 mm spaced internal steel ties. In the case of 100 mm internal steel ties, the difference (between the hoops & spiral CFRP strengthening) is close to 4%. In contrast, there is no difference between the two methods of strengthening in the heavily tied columns (70 mm tied spacing).

The Axial Load-Carrying Capacity of Radial Cylindrical Roller Bearings

1970 ◽  
Vol 92 (1) ◽  
pp. 129-134 ◽  
Author(s):  
H. Korrenn
Keyword(s):  
Carrying Capacity ◽  
Hydrodynamic Lubrication ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Oil Viscosity ◽  
Application Range ◽  
Roller Bearings ◽  
Load Carrying ◽  
Thrust Load ◽  
Cylindrical Roller

Thrust load transmission at the contact areas of roller ends and flanges occurs under conditions of pure sliding. Recent theoretical and experimental investigations showed that with adequately designed roller ends and flanges and with a satisfactory lubricant high thrust loads can be accommodated over a wide speed range with fully hydrodynamic lubrication. The conventional methods used for the determination of the safe thrust load should be revised and supplemented. Oil viscosity should be introduced as an important parameter. Contrary to present opinion the hydrodynamic load-carrying capacity at the flange increases with increasing speed. This new knowledge broadens the application range of radial cylindrical roller bearings.

scholarly journals Load-Carrying Capacity of Short Concrete Columns Reinforced with Glass Fiber Reinforced Polymer Bars Under Concentric Axial Load

2019 ◽  
Vol 9 (2) ◽  
pp. 1712-1719
Keyword(s):  
Carrying Capacity ◽  
Load Capacity ◽  
Plain Concrete ◽  
Concrete Columns ◽  
Reinforcement Ratio ◽  
Load Carrying Capacity ◽  
Rc Columns ◽  
Gfrp Bars ◽  
Glass Fiber Reinforced ◽  
Load Carrying

In this paper, 1 group of plain concrete square columns 150×150×600 mm and 11 groups of concrete columns reinforced with glass fiber reinforced polymer (GFRP) were cast and tested, each group contains of 3 specimens. These experiments investigated effect of the main reinforcement ratio, stirrup spacing and contribution of longitudinal GFRP bars on the load carrying capacity of GFRP reinforced concrete (RC) columns. Based on the experiment results, the relationship between load-capacity and reinforcement ratio and the plot of contribution of longitudinal GFRP bars to load-capacity versus the reinforcement ratio were built and analyzed. By increasing the reinforcement ratio from 0.36% to 3.24%, the average ultimate strain in columns at maximum load increases from 2.64% to 75.6% and the load-carrying capacity of GFRP RC columns increases from 3.4% to 25.7% in comparison with the average values of plain concrete columns. Within the investigated range of reinforcement ratio, the longitudinal GFRP bars contributed about 0.72%-6.71% of the ultimate load-carrying capacity of the GFRP RC columns. Meanwhile, with the same configuration of reinforcement, contribution of GFRP bars to load-carrying capacity of GFRP RC columns decreases when increasing the concrete strength. The influence of tie spacing on load-carrying capacity of reinforced columns was also taken into consideration. Additionally, experimental results allow us to propose some modifications on the existing formulas to determine the bearing capacity of the GFRP RC column according to the compressive strength of concrete and GFRP bars.

scholarly journals Deep nitriding—contact and bending strength of gears with increased nitriding hardening depth

2021 ◽  
Author(s):  
André Sitzmann ◽  
Stefanie Hoja ◽  
Stefan Schurer ◽  
Thomas Tobie ◽  
Karsten Stahl
Keyword(s):  
Carrying Capacity ◽  
Bending Strength ◽  
Experimental Investigations ◽  
Case Hardening ◽  
Load Carrying Capacity ◽  
Industrial Practice ◽  
Aerospace Applications ◽  
Upper Limit ◽  
Load Carrying ◽  
High Fatigue

AbstractThe load carrying capacity of gears can be significantly increased by nitriding. However, the required nitriding hardening depth depends on the stress level and the gear size. In order to achive a high fatigue resistance and durability of nitrided gears an adequate nitriding hardening depth is necessary. In industrial practice, a nitriding hardening depth (NHD) of about 0.6 mm is currently regarded as the upper limit that can be reached within a reasonable time and cost. This also limits of the load carrying capacity of nitrided gears, in particular with increasing gear sizes. Therefore, case hardening is the main treatment used with increasing gear sizes, although nitriding provides some advantages over case hardening. However, with an increased nitriding hardening depth, a significant increase in the load carrying capacity of nitrided gears for medium and larger gear sizes could be expected, which will be discussed in this publication. In order to evaluate the expected potential of the load carrying capacity of nitrided gears with an increased nitriding hardening depth of NHD ≈ 0.8 to 1.0 mm (deep nitriding heat treatment) made out of the materials 31CrMoV9 (1.8519), 30CrNiMo8 (1.6580) and 32CDV13 (alloy for aerospace applications according to AIR 9160), experimental investigations were carried out, which will be discussed in this publication. Both, the tooth root bending strength and the flank load carrying capacity were investigated.

Sign in / Sign up

Export Citation Format

Share Document