Calculation of the fire resistance of steel hollow structural section columns filled with plain concrete

1994 ◽  
Vol 21 (3) ◽  
pp. 382-385 ◽  
Author(s):  
T. T. Lie ◽  
D. C. Stringer
Keyword(s):  
Mathematical Models ◽  
Key Words ◽  
Fire Resistance ◽  
Experimental Studies ◽  
Plain Concrete ◽  
Building Codes ◽  
Aggregate Concrete ◽  
Parametric Studies ◽  
Hollow Structural Section ◽  
Hollow Structural Sections

Experimental studies were conducted to determine the fire resistance of circular and square hollow structural section columns filled with plain concrete. Mathematical models were developed and used to investigate the influence of important parameters that determine the fire resistance of these columns. The experimental and parametric studies provide information for the development of formulas for the calculation of the fire resistance of circular and square concentrically loaded columns filled with plain carbonate or siliceous aggregate concrete. Such formulas are suitable for incorporation into building codes. Key words: calculation, fire resistance, columns, concrete-filled, steel, hollow structural sections.

The Effect of Weld Length on the Tension Capacity of Hollow Structural Section (HSS)

2020 ◽  
pp. 42-58
Keyword(s):  
Cross Section ◽  
Uniform Stress ◽  
Entire Cross Section ◽  
Design Strength ◽  
Minimum Requirement ◽  
Tension Member ◽  
Hollow Structural Section ◽  
Hollow Structural Sections ◽  
Tension Capacity ◽  
Steel Standard

The non-uniform stress distribution occurs in a tension member adjacent to a connection, in which all elements of the cross-section are not directly connected. This effect reduces the member’s design strength because the entire cross-section is not fully effective in the critical section’s location. That's why an experimental study has been done to investigate the effect of the weld length on the tension capacity, two specimens (hollow structural sections) have been tested by using Instron 8800 machine with two weld lengths, 46 mm and 56 mm. The 46 mm size is the minimum requirement of the sufficient size of the tension connection depending on United States Steel Standard. The Result proved that there has been too much effect on the connection carrying tension capacity. The result of the 46 mm weld length is about 155 KN and about 180 KN for the 56 mm weld length. While the ABAQUS simulation results were about 168 KN for the 46 mm weld length and about 172 KN for the 56 mm weld length.

Results of an experimental study of hydrogel drainage containing ranibizumab in antiglaucoma operations

2021 ◽  
pp. 63-67
Author(s):  
I.I. Khusnitdinov ◽  
Keyword(s):  
Experimental Study ◽  
Hyaluronic Acid ◽  
Key Words ◽  
Experimental Research ◽  
Experimental Studies ◽  
Glaucoma Surgery ◽  
Control Group ◽  
Morphological Studies

Purpose. Еxperimental substantiation of the effectiveness of biocompatible biodegradable hydrogels based on hyaluronic acid and chitosan succinate as a carrier of ranibizumab in antiglaucoma operations. Material and methods. Hydrogel drainage (HD) was obtained immediately before surgery. A solution of ranibizumab (0.23 ml) was mixed with a solution of hyaluronic acid dialdehyde (0.5 ml), then a solution of chitosan succinate (0.5 ml) was added. Experimental studies were performed in 12 (12 eyes) healthy rabbits. The first group consisted of 6 eyes – 0.187 ml of ranibizumab per 1 ml of gel. In the control group, HD was used intraoperatively without the addition of ranibizumab (6 eyes). Morphological studies were performed on 7th, 21st, and 42nd days. Results. In experimental studies in vitro and in vivo, it was proved that ranibizumab, administered as a part of 0.1 ml of hydrogel drainage in the antiglaucoma surgery area is released within 3 weeks and suppresses vascularization, scarring of the operating area, and preserves the intrascleral cavity. The optimal concentration of ranibizumab was selected-0.02 ml in 0.1 ml of gel. Conclusion. The safety and effectiveness of the use of hydrogel drainage with ranibizumab based on hyaluronic acid dialdehyde and chitosan succinate in anti-glaucoma operations has been proven. Key words: experimental research, hydrogel drainage, ranibizumab, glaucoma surgery.

Deaf and Hard-of-hearing Users Evaluating Designs for Highlighting Key Words in Educational Lecture Videos

2021 ◽  
Vol 14 (4) ◽  
pp. 1-24
Author(s):  
Sushant Kafle ◽  
Becca Dingman ◽  
Matt Huenerfauth
Keyword(s):  
Experimental Study ◽  
Key Words ◽  
Hard Of Hearing ◽  
Experimental Studies ◽  
Design Parameters ◽  
Educational Video ◽  
Word Level ◽  
Sentence Level ◽  
First Occurrence ◽  
Educational Videos

There are style guidelines for authors who highlight important words in static text, e.g., bolded words in student textbooks, yet little research has investigated highlighting in dynamic texts, e.g., captions during educational videos for Deaf or Hard of Hearing (DHH) users. In our experimental study, DHH participants subjectively compared design parameters for caption highlighting, including: decoration (underlining vs. italicizing vs. boldfacing), granularity (sentence level vs. word level), and whether to highlight only the first occurrence of a repeating keyword. In partial contrast to recommendations in prior research, which had not been based on experimental studies with DHH users, we found that DHH participants preferred boldface, word-level highlighting in captions. Our empirical results provide guidance for the design of keyword highlighting during captioned videos for DHH users, especially in educational video genres.

scholarly journals The mathematical models for cutting force calculation during structural and corrosion-resistant steels` parts processing

2019 ◽  
Vol 298 ◽  
pp. 00099
Author(s):  
Alexey A. Zhdanov ◽  
Oleg A. Kursin ◽  
Pham Xuan Bach
Keyword(s):  
Mathematical Models ◽  
Cutting Force ◽  
Experimental Studies ◽  
Additional Parameter ◽  
Corrosion Resistant ◽  
Cutting Force Components ◽  
Force Components ◽  
Quantitative Indicators ◽  
Force Calculation ◽  
Thermo Physical Properties

The paper shows that conventional mathematical models for calculating the cutting force components during the turning process, represented in reference guides on engineering, give drastic errors reaching 100 percent or more for various tool-workpiece couples. These errors interfere with applying reference values of the cutting force for any further calculations, equipment selection, workpiece positioning scheme, workpiece deformation value due to the elastic of the technological system elements during processing and etc., because of the insufficient reliability of the results of such calculations. The paper proposes mathematical models obtained as a result of experimental studies, which allow for increasing the accuracy of the calculation of the components of the cutting force by introducing an additional parameter – i.e., the value of thermo EMF of the test running into the calculation formulas. This approach enables to reduce the error in the calculation of the components of the cutting force up to ± 15%. In addition, the need for the development of specific mathematical models for various groups of materials machined is shown, which is due to the peculiarities of contact processes in the machining of various groups of steels, as well as to qualitative and quantitative indicators of the thermo-physical properties of the materials of tool-workpiece contact couples.

Pembentukan Diafragma Beralun Silikon Dengan Menggunakan Teknik Punaran Anisotropik

2012 ◽  
Author(s):  
Norhayati Soin ◽  
Burhanuddin Yeop Majlis
Keyword(s):  
Key Words ◽  
Experimental Studies ◽  
Anisotropic Etching ◽  
Etching Technique ◽  
Convex Corner ◽  
Mask Design ◽  
Etching Mask ◽  
Corrugated Diaphragm

Kertas ini memaparkan kajian mengenai pembentukan diafragma beralun silikon dengan menggunakan teknik punaran anisotropik di mana larutan kalium hidroksida digunakan sebagai larutan pemunar. Kajian ini meliputi pengoptimuman topeng punaran bagi mengatasi masalah keadaan potong bawah penjuru yang berlaku pada struktur berpenjuru cembung diafragma beralun yang terpunar. Hasil yang diperolehi daripada kajian simulasi dan eksperimen membuktikan bahawa pengoptimuman topeng punaran yang telah dilakukan berkemampuan mengatasi masalah potong bawah penjuru diafragma beralun silikon. Kata kunci: diafragma beralun, punaran anisotropik, pengoptimuman topeng This paper presents the study of the formation of a perfect silicon corrugated diaphragm using anisotropic etching technique. Potassim hydroxide (KOH) solution is used as the etching solvent in this study. This study includes optimization of the etching mask, in order to avoid the problem of corner undercutting which exists on all convex corner structures on the etched corrugated diaphragm. Results from the simulation and experimental studies have proved that the optimized etching mask design was able to overcome the problem of convex corner undercutting. Key words: corrugated diaphragm, anisotropic etching, mask optimization

Performance of high strength concrete-filled steel columns exposed to fire

1998 ◽  
Vol 25 (6) ◽  
pp. 975-981 ◽  
Author(s):  
VKR Kodur
Keyword(s):  
Fire Resistance ◽  
High Strength Concrete ◽  
High Strength ◽  
Experimental Program ◽  
Structural Behaviour ◽  
Steel Columns ◽  
Strength Concrete ◽  
Normal Strength ◽  
Concrete Filling ◽  
Hollow Structural Section

Results from an experimental program on the behaviour of high strength concrete-filled steel hollow structural section (HSS) columns will be presented for three types of concrete filling. A comparison will be made of the fire-resistance performance of HSS columns filled with normal strength concrete, high strength concrete, and steel-fibre-reinforced high strength concrete. The various factors that influence the structural behaviour of high strength concrete-filled HSS columns under fire conditions are discussed. It is demonstrated that, in many cases, addition of steel fibres into high strength concrete improves the fire resistance and offers an economical solution for fire-safe construction.Key words: high strength concrete, steel columns, fire-resistance design, high-temperature behaviour, concrete-filled steel columns.

Design of single-angle compression members according to the Canadian standards

1996 ◽  
Vol 23 (3) ◽  
pp. 632-638 ◽  
Author(s):  
Murray C. Temple
Keyword(s):  
United States ◽  
Key Words ◽  
Failure Modes ◽  
The United States ◽  
Building Codes ◽  
Flow Chart ◽  
Structural Elements ◽  
Compression Members ◽  
Principal Axes ◽  
The Many

Although single-angle compression members, attached by one leg, appear to be very simple structural elements, they are amongst the most complex of structural elements to analyze and design. This is due to the end eccentricities and the fact that the principal axes of the angle do not coincide with the axis of the structure. The design of single-angle compression members, according to the Canadian standards, is not as straightforward as might be expected. There are numerous clauses to be considered in two standards. In some cases, all failure modes are not covered explicitly. The Canadian standards are examined and applied to the two generally accepted design approaches used in Canada and the United States. These approaches are (i) to ignore the end eccentricities and to treat the angle as a concentrically loaded member and (ii) to account for the end eccentricities by treating the angle as a beam–column. A flow chart is presented which will guide the designer through the many clauses that have to be considered in the two standards. Some suggestions are made which should help a practicing engineer design single-angle compression members that are attached by one leg. Key words: angles, buckling, building (codes), design.

Investigation on Seismic Behavior of Recycled Aggregate Concrete Structures under Dynamic Loadings

2013 ◽  
Vol 772 ◽  
pp. 149-155
Author(s):  
Chang Qing Wang
Keyword(s):  
Seismic Behavior ◽  
Fatigue Behavior ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Recycled Aggregate Concrete ◽  
Shaking Table ◽  
Frame Structure ◽  
Recycled Aggregate ◽  
Scale Model ◽  
Aggregate Concrete

Based on the ever finished investigations of physical and mechanical properties of recycled aggregate concrete (RAC), and a series of experimental studies on the durability, the fatigue behavior, mechanical behavior and the seismic behavior of RAC components. A full scale model of a one-storey block masonry structure with tie column + ring beam + cast-in-place slab system and a one fourth scaled model of a 6-storey frame structure, which are made of reinforced recycled aggregate concrete, are tested on a shaking table by subjecting it to a series of simulated seismic ground motions, and the seismic behaviors of the RAC structures were experimentally investigated. The dynamic characteristics and the seismic response were analyzed and discussed. The overall seismic performance of RCA structures are evaluated, the analysis results show that the recycled aggregate concrete structures with proper design exhibits good seismic behavior and can resist the earthquake attacks under different earthquake levels in this study. It is feasible to apply and popularize the RAC block masonry buildings less than 2 stories and the RAC frame buildings less than 6 stories in the region where the seismic fortification intensity is 8.

Dynamics of the brain: Mathematical models and non-invasive experimental studies

2013 ◽  
Vol 222 (10) ◽  
pp. 2607-2622 ◽  
Author(s):  
V. Toronov ◽  
T. Myllylä ◽  
V. Kiviniemi ◽  
V.V. Tuchin
Keyword(s):  
Mathematical Models ◽  
Experimental Studies ◽  
Non Invasive ◽  
The Brain
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