The Hardness of Very Soft Rubbers

1956 ◽  
Vol 29 (3) ◽  
pp. 852-856
Author(s):  
R. F. Blackwell
Keyword(s):  
Calibration Curve ◽  
Laboratory Work ◽  
Dead Load ◽  
Scale Reading ◽  
British Standard ◽  
Hardness Tester ◽  
Alternative Method ◽  
The Dead ◽  
Dial Gauge

Abstract Hardness determinations are frequently required on very soft rubbers in the range of 5 to 30 (Shore). It is usual to make such measurements in the shop with a pocket-type tester; however this is not entirely satisfactory for laboratory work where a more precise reading is usually required, calling for a hardness tester of the dead-load type. Such a tester, moreover, is useful to keep a check on the accuracy of pocket testers. The British Standard dead-load hardness tester is not calibrated below 30° BS, but a method of extending the range downwards has been proposed, whereby the standard indentor of this tester is replaced by one of 0.25 inch diam.; unfortunately this method has the disadvantage of involving more than one revolution of the dial gauge needle, and a directly calibrated scale would be out of the question. There is, however, an alternative method in use at BRPRA, which gives hardness readings down to 4° in one revolution; and which replaces the standard added load of 535 grams by one of 70 grams. At present, a calibration curve is provided to convert from scale reading to hardness degrees, but it is intended to add a second scale in due course.

An Alternative Method for Identifying a Failed Engine in Twin-Engine Propeller Aircraft

2020 ◽  
Vol 10 (2) ◽  
pp. 103-111
Author(s):  
Andrey K. Babin ◽  
Andrew R. Dattel ◽  
Margaret F. Klemm
Keyword(s):  
Human Error ◽  
Flight Simulator ◽  
Traditional Group ◽  
Aircraft Accidents ◽  
Alternative Method ◽  
Indicator Group ◽  
Group A ◽  
The Dead ◽  
Engine Failure ◽  
And Performance

Abstract. Twin-engine propeller aircraft accidents occur due to mechanical reasons as well as human error, such as misidentifying a failed engine. This paper proposes a visual indicator as an alternative method to the dead leg–dead engine procedure to identify a failed engine. In total, 50 pilots without a multi-engine rating were randomly assigned to a traditional (dead leg–dead engine) or an alternative (visual indicator) group. Participants performed three takeoffs in a flight simulator with a simulated engine failure after rotation. Participants in the alternative group identified the failed engine faster than the traditional group. A visual indicator may improve pilot accuracy and performance during engine-out emergencies and is recommended as a possible alternative for twin-engine propeller aircraft.

The Ultimate Shear Bearing Capacity of RC Beam Strengthened with SWR External Prestressing under Dead Load Level when Strengthening

2011 ◽  
Vol 368-373 ◽  
pp. 2175-2179
Author(s):  
Tian Lai Yu ◽  
Hong Kun Han ◽  
Xin Yu Li ◽  
Qiang Ma
Keyword(s):  
Bearing Capacity ◽  
Concrete Beams ◽  
Steel Wire ◽  
Load Level ◽  
Shear Capacity ◽  
Dead Load ◽  
External Prestressing ◽  
Reduction Coefficient ◽  
Shear Bearing Capacity ◽  
The Dead

The shear resistant with SWR (steel wire rope) external prestressing is a kind of new type of reinforcement technique. The advantages of the method are ideal reinforcement effect, durability, and convenient construction. So the method has been paid attention by more and more scientists and technical workers. Through the experiment of 1 basic beam and 3 strengthened beams which are in different dead load levels, the influence of damage degree of original beams and the dead load level of strengthened beams are analyzed. The reduction coefficient values of shear capacity under different dead load level are researched. The research is shown that: with the dead load level increasing, the improve degree of shear capacity of strengthened concrete beams is smaller. The mathematical model is established, which is about dead load level and reduction coefficient of shear capacity of strengthened concrete beams. The result is to take 0.75 as the reduction coefficient of shear capacity. The value is reasonable in calculating the shear bearing capacity of strengthened beams under dead load.

scholarly journals Numerical Analysis of Dead Load Shear Force Distribution in Webs of Multicell Inclined Web Box-Girder Bridge

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xingwei Xue ◽  
Meizhong Wu ◽  
Zhengwei Li ◽  
Peng Zhou
Keyword(s):  
Load Distribution ◽  
Shear Force ◽  
Cell Number ◽  
Force Distribution ◽  
Distribution Factor ◽  
Dead Load ◽  
Bridge Design ◽  
Box Girders ◽  
Box Girder ◽  
The Dead

Moment and shear load distribution are important in bridge design. Most existing studies have focused on the distribution of girders under vehicle loading, neglecting the dead load distribution between the webs of multicell box-girders. Through the “Sum of Local Internal Forces” function, the shear force of each web in the multicell box-girder 3D finite element model was extracted and analysed using the dead load shear force distribution factor. The research parameters include the slope of the web, support condition, and cell number with respect to the dead load shear force distribution factor. The results indicate that the dead load shear distribution in the webs of multicell box-girders is uneven. The outermost inclined web bears a shear force greater than the average shear force, which must be considered in bridge design.

scholarly journals Effect of Dead Load on Dynamic Characteristics of Rotating Timoshenko Beams

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yan-Qi Yin ◽  
Bo Zhang ◽  
Yue-ming Li ◽  
Wei-Zhen Lu
Keyword(s):  
Finite Element ◽  
Cantilever Beam ◽  
Dynamic Characteristics ◽  
Timoshenko Beam ◽  
Natural Frequencies ◽  
Experimental Result ◽  
Dead Load ◽  
Rotating Speed ◽  
Experimental Apparatus ◽  
The Dead

The dynamic characteristics of a rotating cantilever Timoshenko beam under dead load are investigated in this paper. Considering the predeformation caused by dead load and centrifugal force, governing equation of rotating cantilever Timoshenko beam is derived based on Hamilton’s principle, and the influence of the load on natural vibration is revealed. A suit of modal experimental apparatus for cantilever beam is designed and used to test the natural frequencies under the dead load, and the natural frequencies under rotation condition are calculated with a commercial finite element code. Both the experimental result and numerical result are utilized to compare with the present theoretical result, and the results obtained by present modeling method show a good agreement with those obtained from the experiment and finite element method. It is found that the natural frequencies of cantilever beam increase with both the dead load and the rotating speed.

scholarly journals STUDI KASUS KEMIRINGAN GEDUNG 4 LANTAI AKIBAT KEGAGALAN FONDASI DI PANGKAL PINANG

2021 ◽  
Vol 4 (3) ◽  
pp. 615
Author(s):  
Orlando Orlando ◽  
Gregorius Sandjaja Sentosa
Keyword(s):  
Bearing Capacity ◽  
Secondary Data ◽  
Dead Load ◽  
Considerable Decrease ◽  
Building Site ◽  
Pile Cap ◽  
Bore Pile ◽  
Lower Structure ◽  
The Dead

Foundation is the lower structure of the building located below the ground that has the function to bear the load of the building. The building has been standing for ± 5 years and the slope of the building is ± 1-20. The authors analyzed soil bearing capacity, settlement and the slope of the building and the possibility of repairing the building for reuse. In 1 pile cap there are 4 bore piles with a depth of 6m-12m, because the pile cap data is not obtained then the size and thickness is assumed and the soil data used is secondary data without lab data derived from soil data in locations adjacent to the building site that is ±100m from the building site. After the analysis, soil bearing capacity is not strong to bear the dead load of the building when using a foundation with a depth of 6m-12m, there is a possibility that the foundation used is not suitable and there is a reduction in the load of the building due to the presence of other buildings that are adjacent to the building in the analysis resulting in a considerable decrease and slope of the building.Fondasi adalah struktur bagian bawah bangunan yang terletak di bawah permukaan tanah yang mempunyai fungsi memikul beban bangunan. Bangunan ini sudah berdiri selama ± 5 tahun dan  kemiringan bangunan sebesar ± 1-20. Penulis menganalisis daya dukung tanah, penurunan tanah dan kemiringan bangunan dan kemungkinan memperbaiki bangunan agar dapat digunakan kembali. Pada 1 pile cap terdapat 4 buah bore pile dengan kedalaman 6m–12m, karena data pile cap  tidak diperoleh maka ukuran dan ketebalannya diasumsikan dan data tanah yang digunakan adalah data sekunder tanpa data lab yang berasal dari data tanah di lokasi berdekatan dengan lokasi bangunan yang berjarak ±100m dari lokasi bangunan. Setelah di analisis, daya dukung tanah tidak kuat untuk menahan beban mati bangunan bila menggunakan fondasi dengan kedalaman 6m–12m dan ada kemungkinan fondasi yang digunakan tidak sesuai dan terjadi reduksi beban bangunan karena adanya bangunan lain yang berdempetan dengan bangunan yang di analisis sehingga mengakibatkan penurunan dan kemiringan bangunan yang cukup besar.

An alternative method of administering alkane markers for estimating intake in dairy cows

1999 ◽  
Vol 1999 ◽  
pp. 91-91
Author(s):  
Y. Unal ◽  
P.C. Garnsworthy
Keyword(s):  
Food Intake ◽  
Dairy Cows ◽  
Laboratory Work ◽  
Naturally Occurring ◽  
Alternative Method ◽  
Hard Shell ◽  
Animal Handling ◽  
Basal Ration

Alkanes have been used for a number of years to estimate food intake in ruminants. The technique requires animals to be dosed with synthetic even-chained alkanes, usually C32 and C36; faecal concentrations of these are then compared with naturally-occurring alkanes, e.g. C33, to estimate intake. Mayes et al. (1986) prepared capsules containing alkanes on shredded paper; Dove et al. (1988) used hard-shell gelatine capsules to administer dosed alkanes. Both methods required animal handling, extra material, like gelatine capsules or paper, and also some laboratory work for preparing alkane solutions, papers and capsules. We report here a less time-consuming method that can be used with dairy cows or other animals offered concentrates separately from a basal ration. The objective of the study was to see how accurately food intake in dairy cows could be estimated when dosed alkanes are administered via a compound feed.

Sensitivity Analysis of Continuous Curved Bridge under Different Curvature Radius

2014 ◽  
Vol 587-589 ◽  
pp. 1650-1654
Author(s):  
Mu Xin Luo ◽  
Jing Hong Gao
Keyword(s):  
Moving Load ◽  
Bending Moment ◽  
Element Model ◽  
Internal Force ◽  
Curvature Radius ◽  
Moving Loads ◽  
Dead Load ◽  
Actual Structure ◽  
Curved Bridge ◽  
The Dead

In the condition of the same span, to change the continuous curved bridge's curvature radius and under the dead load and moving load to compare how the internal force changes in different curvature radius. The finite element model is established to simulate the actual structure by Midas Civil. Results in a continuous curved bridge which main span of less than 60m, under the dead load, bending moment (-y) is unlikely to change, reinforced by a straight bridge can meet the requirements; under the moving loads, the curvature radius of the bending moment (-y) has little influence, should focus on increase in torque and bending moment (-z).

The Standardization of Durometers

1940 ◽  
Vol 13 (4) ◽  
pp. 969-978
Author(s):  
Lewis Larrick
Keyword(s):  
Standard Method ◽  
Hardness Test ◽  
Type A ◽  
Test Sample ◽  
Dead Load ◽  
Dead Weight ◽  
Pressure Gage ◽  
Hardness Tester ◽  
Vulcanized Rubber ◽  
Physical Tests

Abstract The hardness test is one of the most useful and convenient physical tests which can be made on vulcanized rubber. It is easily made because the equipment can be simple, compact and portable. It is particularly useful in that the test sample may be a production article which can be put into service, undamaged, after the test. Consequently the test appears in the industry in several modifications, and the tester in diverse styles. Several more or less readily portable hardness testers are available commercially. The Shore Instrument and Manufacturing Co. has its line of Durometers, types A, B, C, D, etc.; Schopper, through Testing Machines, Inc., has marketed a tester similar to the Shore type A; the U. S. Gauge Co. has an instrument of the same type using the case of their pressure gage; the Firestone Penetrometer is another well-known tester of the spring-load type, as is the Adams Densimeter. At the present time the Society's Committee D-11 on Rubber Products is studying four portable hardness testers which are based on the specifications of the Standard Method of Test for Hardness of Rubber (D314-39), three of these being spring-operated instruments, the fourth, a dead-load type. In addition to the testers mentioned above, there is the Pusey-Jones Plastometer, which is a dead-weight hardness tester rather than a plastometer.

scholarly journals Stress distribution in column-plate foundations of Monument of Christ The King erected in Świebodzin

2020 ◽  
pp. 37-47
Author(s):  
Jakub Marcinowski ◽  
Volodymyr Sakharov
Keyword(s):  
Stress Distribution ◽  
Numerical Simulations ◽  
Side Surface ◽  
Wind Load ◽  
Vertical Load ◽  
Structural Members ◽  
Dead Load ◽  
Initial State ◽  
The Dead ◽  
Resultant Forces

The paper presents results of numerical simulations of the stress distribution and deformations within of foundations of huge monument of Christ The King erected in Świebodzin (Poland) in 2010. It is 3 meters taller than the better known statue of Christ the Redeemer in Rio de Janeiro, standing at 30.1 meters tall without its pedestal. Foundations were built as a system of reinforced concrete columns and slabs which can be classified as a spatial column-slab system. Actual mechanical parameters of the substrate and of the artificial mound made of field stones, sand, gravel and clay were adopted in calculations. The numerical simulations of structural members of foundation and determination of the stress distribution are presented in the article. Monument itself was not included into the model. Instead of it the rigid cantilever was introduced to which resultant forces were applied. Three different stages were distinguished: the initial state after foundation and mound accomplishment, the initial state plus the dead load and the initial state plus the dead load and the wind load. It was assumed that the wind load was taken into account in a quasi-static formulation by applying the equivalent horizontal force and the torque. Stresses and displacements for these three stages were determined by Finite Element Method using Simulia ABAQUS system. It was disclosed what was a contribution of particular parts of foundations in sustaining loads in considered load cases. The state of exertion of structural members of foundations and the soil itself was assessed. It was showed that the column-slab foundations and soils of the mound play important role in taking loads of the statue, spreading them and safe transferring to the undisturbed level of natural soils. According to the numerical simulations results the columns of foundation take as much as 64% of the vertical load (in the most unfavourable load conditions). At the same time soils of the mound take through the side surface of piles about 20 % of the vertical load.

Sign in / Sign up

Export Citation Format

Share Document