scholarly journals About problems with cast iron columns of the revitalized post-industrial buildings

2019 ◽  
Vol 284 ◽  
pp. 05010
Author(s):  
Tadeusz Urban ◽  
Michał Gołdyn
Keyword(s):  
Cast Iron ◽  
Carrying Capacity ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Design Procedures ◽  
Industrial Buildings ◽  
Load Carrying ◽  
Material Uncertainties ◽  
Post Industrial ◽  
Existing Structure

The paper discusses examples of the use of cast iron columns in existing post-industrial buildings. The results of experimental investigations in which a cast iron column originating from an existing structure was subjected to compression, were presented. The load carrying capacity of the element was assessed in the light of historical design procedures, demonstrating their conservativeness resulting from material uncertainties. The examples of failures of cast iron columns, resulting from errors committed during modernization works, were also presented.

scholarly journals The Selected Issues of Adaptation of 19th and 20th Century Post-Industrial Buildings in Łódź

2020 ◽  
Vol 5 (8) ◽  
pp. 69
Author(s):  
Tadeusz Urban ◽  
Michał Gołdyn
Keyword(s):  
Cast Iron ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Reinforced Concrete Structure ◽  
Technical Problems ◽  
Historical Structures ◽  
Industrial Buildings ◽  
Load Carrying ◽  
Historical Masonry ◽  
Post Industrial

The paper deals with selected technical problems related to the adaptation for new uses of the structure of existing post-industrial buildings from the turn of the 19th and 20th centuries. A major difficulty is the fact that the strength and geometric properties of cast-iron, steel, and masonry elements often differ significantly from the values characterizing contemporary materials. Due to uncertainty regarding the load-carrying capacity of historical structures, in many cases there is a need to carry out destructive tests of elements taken from the buildings. As the example of cast-iron girders in the former spinning mill of “I. Poznański” demonstrated, such tests can prove a significant margin of load-carrying capacity and confirm the possibility of adapting the structure to new purposes. The paper also presents examples of strengthening the existing wooden ceilings by joining with the reinforced concrete structure, which allowed the keeping of the original elements and an increase of the allowable load. Selected problems related to the assessment of historical masonry structures were also described. The discussed examples of structural failures showed that they often resulted from incorrect assessment of the strength of historical masonry elements as well as improperly conducted construction works.

scholarly journals Failures of the Cast-Iron Columns of Historic Buildings—Case Studies

2020 ◽  
Vol 5 (9) ◽  
pp. 71
Author(s):  
Michał Gołdyn ◽  
Tadeusz Urban
Keyword(s):  
Cast Iron ◽  
20Th Century ◽  
Design Principles ◽  
Experimental Investigations ◽  
Engineering Structures ◽  
Technical Problems ◽  
Industrial Buildings ◽  
Material Uncertainties ◽  
19Th And 20Th Century ◽  
Post Industrial

Selected technical problems related to the rehabilitation of cast-iron columns in structures from the turn of the 19th and 20th century are discussed in the paper. Lack of contemporary standard regulations related to the design of cast-iron structures is a significant problem in the design works and experimental investigations on cast-iron columns are frequently required. The paper presents results of the tests concerning principal properties of cast-iron—strength and deformability. The historical design principles are discussed in the light of the results of experimental investigations. As it was demonstrated, the actual load-carrying capacities of cast-iron columns may exceed by several times the values resulting from the 20th century design rules. The conservatism of the design principles resulted, however, from the material uncertainties—lack of homogeneity and hidden defects of the cast-iron. Selected examples of failures of cast-iron columns from 19th-century structures such as post-industrial buildings and engineering structures are discussed. They resulted from errors made during adaptation works. The reasons for these failures and considered methods of repairing the structures are presented.

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 Starred angles supporting secondary trusses

1991 ◽  
Vol 18 (1) ◽  
pp. 118-129
Author(s):  
Murray C. Temple ◽  
Kenneth Hon-Wa Mok
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Slenderness Ratio ◽  
The Other ◽  
Load Carrying Capacity ◽  
Industrial Buildings ◽  
Compression Members ◽  
Load Carrying ◽  
Structural Connections ◽  
Open Nature

In some large industrial buildings, it is common to span large areas by using primary trusses in one direction and secondary trusses in the other. The secondary trusses frame into the vertical web members in the primary trusses. Starred angles are frequently used as the vertical web members in the primary trusses because of their symmetrical cross section and the ease with which the connections can be made. These starred angles are usually designed as axially loaded members, but the open nature of the cross section and the fact that the secondary truss frames into one of the angles has raised some doubts about this loading assumption. As a result of this concern, an experimental research program was undertaken to investigate the behaviour and strength of starred angle web members supporting secondary trusses. The results obtained indicate that these starred angle compression members are not concentrically loaded, as the stress distribution across the angles is not uniform. It was found that if the slenderness ratio is modified in accordance with the requirements of ASCE Manual 52, the load-carrying capacity of the starred angles supporting secondary trusses can be determined using Clause 13.3.1 of CAN3-S16.1-M84. Key words: angles (starred), buckling, columns (structural), connections, trusses.

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 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.

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.

Evaluation of pile load tests in the Edmonton area

1981 ◽  
Vol 18 (2) ◽  
pp. 313-316 ◽  
Author(s):  
S. Thomson
Keyword(s):  
Test Data ◽  
Carrying Capacity ◽  
Vertical Movement ◽  
Load Carrying Capacity ◽  
Design Procedures ◽  
Concrete Piles ◽  
Load Carrying ◽  
Load Tests ◽  
Pile Load Tests

The design of cast-in-place concrete piles is essentially empirical; hence, an examination of commercial pile load tests is of value. The test data of four pile load tests consisted of the vertical movement of the top of the pile and the load on top of the pile. It was therefore necessary to calculate the shaft and base loads assuming that the till was homogeneous with regard to strength over the length of the pile.The results of the back analyses suggest that the design procedures are valid within practical limits for the prediction of load carrying capacity and for immediate settlement.

scholarly journals Effect of Use Recycled Coarse Aggregate on the Behavior of Axially Loaded Reinforced Concrete Columns

2019 ◽  
Vol 25 (10) ◽  
pp. 88-107
Author(s):  
Omar Shamal Farhan
Keyword(s):  
Carrying Capacity ◽  
Coarse Aggregate ◽  
Concrete Strength ◽  
Steel Fibers ◽  
Environmental Benefits ◽  
Recycled Aggregates ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Axially Loaded

Nowadays, the use of recycled waste construction materials instead of aggregates is becoming popular in construction owing to its environmental benefits. This paper presents an experimental and analytical campaign to study the behavior of axially loaded columns constructed from recycled aggregates. The latter was used instead of natural aggregates, and they were collected from the waste of previous concrete constructions. Different concrete mixtures made from varying amounts of recycled aggregates ranged from 0 to 50% of the total coarse aggregate were conducted to achieve 28 MPa. The effect of steel fibers is another investigated variable with volumes ranged from 0 to 2% concerning concrete’s mixture. The experimental results showed that the concrete strength is dependent on the amount of recycled aggregates. When the recycled aggregates were less than 30% of the total aggregates, they had a negligible effect on concrete strength and the load carrying capacity of the column models were improved. Also, the presence of steel fibers enhanced the load carrying capacity of the columns constructed from concrete with recycled aggregates of more than 30%. Finite element analysis (using ANSYS 16.1 software program) was conducted to simulate the experimental investigations, and they achieved good agreements with the test results.

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