Combined effects of end distance and spacing on the resistance of split ring connectors loaded in tension

1994 ◽  
Vol 21 (5) ◽  
pp. 789-796 ◽  
Author(s):  
A. Charron ◽  
P. Quenneville
Keyword(s):  
Experimental Study ◽  
Key Words ◽  
Engineering Design ◽  
Linear Relation ◽  
Combined Effects ◽  
Split Ring ◽  
Design Standard ◽  
Design Philosophy ◽  
End Distance

An experimental study was undertaken to verify the combined effects of timber connector end distance and spacing requirements of the Canadian standard for engineering design in wood. A total of 130 test specimens using 63 mm diameter split rings were loaded to failure in tension. The split ring end distance varied between 50 and 210 mm and the spacing varied between 80 and 200 mm. Results show that a linear relation exists between the connector end distance and its resistance for a given spacing. Increase in spacing also results in an increase of the connector resistance for a given end distance. Also, connections with two connectors in a row can resist significant loads even if the end distance or spacing of one connector is below the standard minimum required value. Thus, the design philosophy of Clause 10.3.3 of the wood design standard is inadequate for these joints. Key words: split ring, tension, end distance, spacing, resistance, timber.

Behaviour of single and double 102 mm split ring conneotions loaded in tension

1996 ◽  
Vol 23 (3) ◽  
pp. 602-613 ◽  
Author(s):  
J. H. P. Quenneville ◽  
J. G. A. Charron
Keyword(s):  
Key Words ◽  
Significant Influence ◽  
Experimental Studies ◽  
Combined Effects ◽  
Split Ring ◽  
Direct Function ◽  
Design Standard ◽  
Design Philosophy ◽  
End Distance

Two experimental studies were undertaken to verify the effect of the end distance on the resistance of single connector joints using 102 mm split rings and the combined effects of timber connector end distance and spacing on the resistance of double connector joints using 102 mm split rings. A total of 108 test specimens were loaded to failure in tension. Sixty of those tests were single connector joints with end distances varying from 80 to 270 mm. The remaining 48 test specimens were double connector joints with split ring end distances varying from 100 to 270 mm and a spacing of either 125 or 230 mm. The single connector joints results showed an increase in connector resistance with the increasing end distance. However, it was shown that even though some specimens were tested at an end distance below the standard minimum required value (end distance of 80 mm instead of the minimum required of 135 mm), they resisted a significant load. For the double connector joints, it was observed that brittle failures are more common, as opposed to single connector joints which tend to fail showing signs of ductility. Also, results showed that the connection resistance is not a direct function of the number of fasteners and that a factor of 0.475 has to be applied. Results obtained suggested that the end distance does not have a statistically significant influence on the resistance of connections with connector spacing at either 230 or 125 mm. However, the spacing of the connectors appears to affect the resistance. Thus, the design philosophy of Clause 10.3.3 of the wood design standard is inadequate for these particular joints. Recommendations to determine connection resistances are provided. Key words: wood, fasteners, resistance, split ring, end distance, spacing.

The enhanced performance of split-ring connections through prestressing

1991 ◽  
Vol 18 (5) ◽  
pp. 830-838 ◽  
Author(s):  
J. H. P. Quenneville ◽  
K. Van Dalen
Keyword(s):  
Key Words ◽  
Engineering Design ◽  
Laboratory Study ◽  
Laboratory Tests ◽  
Simple Technique ◽  
Douglas Fir ◽  
Limit States ◽  
Split Ring ◽  
Lap Splices

This paper examines the concept of enhancing the performance of timber connectors in truss joints by the introduction of transverse prestressing. The behaviour of lap splices of Douglas fir, with 63 mm split-ring connectors and end distances of 50, 100, 150, and 210 mm, was examined for various levels of prestress in a laboratory study. As well, the magnitude of the load that can be carried by the connection through friction between faying surfaces was also assessed for various levels of prestress. The simple technique used in the laboratory for introducing prestress is described. Results of the laboratory tests on 20 joint configurations are presented, and the experimentally determined strengths are compared with the calculated resistances using the provisions of CAN\CSA-086.1-M89 "Engineering design in wood (limit states design)." Key words: timber, connector, prestress, truss joint.

Effect of end distance on the resistance of split ring connectors in timber joints loaded in compression

1993 ◽  
Vol 20 (5) ◽  
pp. 863-871 ◽  
Author(s):  
Pierre Quenneville ◽  
Alain Charron ◽  
Karl Van Dalen
Keyword(s):  
Engineering Design ◽  
Species Group ◽  
Douglas Fir ◽  
Experimental Program ◽  
Split Ring ◽  
Ring Compression ◽  
Larch Species ◽  
Cleavage Strength ◽  
End Distance ◽  
Timber Joints

An experimental program was undertaken to verify the end distance requirements in the Canadian standard for engineering design in wood for split ring connectors in joints loaded in compression. In a laboratory study, 48 joints of the Douglas fir-larch species group using 63 mm diameter split rings, 45 joints of the Douglas fir-larch species group using 102 mm diameter split rings, and 51 joints of the spruce-pine-fir species group using 63 mm diameter split rings were loaded to failure in compression. The split ring end distance varied between 50 and 200 mm for joints with 63 mm diameter split rings and between 80 and 220 mm for joints with 102 mm diameter split rings. Tests were also carried out to verify the cleavage strength of the wood and the strength of the wood in compression parallel-to-grain for each of the specimens. Results show that the end distance does not have any significant effect on the resistance of split ring connectors in joints with members loaded in compression. Key words: split ring, compression, end distance, timber, resistance.

Effect of end distance on the resistance of spilt ring and shear plate connectors loaded perpendicular to grain

1996 ◽  
Vol 23 (5) ◽  
pp. 989-997
Author(s):  
J. H. P. Quenneville ◽  
J. G. A. Charron
Keyword(s):  
Experimental Study ◽  
Species Group ◽  
Douglas Fir ◽  
The Other ◽  
Limit States ◽  
Split Ring ◽  
Ring Shear ◽  
Shear Plate ◽  
Larch Species ◽  
End Distance

An experimental study was undertaken to verify the end distance requirements in the CSA Standard O86.1-94 "Engineering design in wood (limit states design)" for split ring and shear plate connectors in joints loaded perpendicular to grain. In a laboratory study, 48 joints of the Douglas fir – larch species group were loaded to failure perpendicular to grain. Twenty-eight of those joints were tested using 102 mm diameter shear plates, and the remaining 20 joints were tested using 63 mm diameter split rings. Of the 28 joints tested with 102 mm shear plates, 16 of the specimens were made of laminated Douglas fir and the other 12 specimens were made of sawn lumber Douglas fir. End distances of 80, 130, 140, and 180 mm were studied for each of the two shear plate tests. Specimens using 63 mm split rings were tested at end distances of 80 and 140 mm. Results show that when using 102 mm shear plate and 63 mm split ring connectors, the end distance of the connector has no statistically significant effect on the resistance of the connector. Changes to the Canadian wood design standard are recommended. Key words: wood, fasteners, resistance, split ring, shear plate, end distance.

Effects of end distance and thickness on the tensile resistance of 102 mm shear plates

1995 ◽  
Vol 22 (6) ◽  
pp. 1113-1119 ◽  
Author(s):  
P. Quenneville ◽  
A. Charron
Keyword(s):  
Experimental Study ◽  
Weibull Distribution ◽  
Key Words ◽  
Tensile Load ◽  
Design Standards ◽  
Unit Clause ◽  
Shear Plate ◽  
End Distance ◽  
Design Requirements ◽  
Two Parameter

In this paper, an experimental study of the behavior of 102 mm shear plates subjected to tensile load is presented. The design requirements for shear plate connectors specified in the last three editions of the Canadian wood design standards (1980, 1984, and 1989) are also reviewed and compared with the experimental results. In the experimental study, 83 specimens were tested with shear plate end distances of 80, 145, 210, and 275 mm. Specimens were either 64 or 89 mm thick. Results for all tests were analyzed and 5th percentile resistance values were obtained for each end distance value, assuming a two-parameter Weibull distribution. Results show that connections using 102 mm shear plate connectors behave in a brittle manner when loaded in tension. It is also shown that the member thickness affects the tensile resistance of shear plates in thin members with small connector end distances and that it appears to impose a limit on the resistance for thin members with large connector end distances. Finally, it is shown that the 75% minimum limit on a member net area adjacent to a connector unit (clause 4.3.7.2 of O86.1-M89) is conservative for members with small connector end distances. Key words: wood, shear plate, end distance, resistance, thickness.

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 COMPOSIÇÃO DE PERFIS RADIAIS DE DISTRIBUIÇÃO DE ÁGUA DE ASPERSORES

Irriga ◽  
2009 ◽  
Vol 14 (1) ◽  
pp. 41-53 ◽  
Author(s):  
Giuliani Do Prado ◽  
Alberto Colombo
Keyword(s):  
Key Words ◽  
Flow Rate ◽  
Linear Relation ◽  
Water Distribution ◽  
Test Bench ◽  
Application Rate ◽  
Water Application ◽  
Irrigation Uniformity ◽  
Nozzle Configuration ◽  
Composition Process

COMPOSIÇÃO DE PERFIS RADIAIS DE DISTRIBUIÇÃO DE ÁGUA DE ASPERSORES  Giuliani do Prado; Alberto ColomboDepartamento de Engenharia, Universidade Federal de Lavras, Lavras, MG, [email protected]  1 RESUMO Este trabalho descreve um procedimento de composição do perfil radial de aspersores que operam com dois bocais. Foram determinados na bancada de ensaios de aspersores da Universidade Federal de Lavras, em Lavras/MG, os valores de vazão e perfil radial do aspersor PLONA-RL250 operando, individualmente, com os bocais principais 14 e28 mme com os bocais auxiliares 5, 6 e7 mm, e operando, nas diferentes seis combinações de bocal auxiliar e principal do aspersor, sob cinco pressões de serviço (292, 392, 490, 588 e 696 kPa). No processo de composição do perfil radial realizado, ajustando a vazão dos bocais auxiliar e principal, operando individualmente, a vazão do aspersor operando com o conjunto de bocais auxiliar e principal, verificou-se um coeficiente de determinação médio de 88,57% entre as intensidades de precipitação adimensionais dos perfis radiais compostos com os perfis radiais do conjunto. Na relação linear, ajustada, entre os valores de uniformidade de equipamentos autopropelidos de irrigação, obtidos com os perfis radiais compostos e do conjunto, a inclinação da reta foi igual a 44°12’com um erro relativo médio de 2,34%. Estes resultados mostram que o procedimento de composição do perfil radial de aspersores não influencia, de maneira significativa, na uniformidade de aplicação de água de aspersores. UNITERMOS: bocais do aspersor, vazão do aspersor, uniformidade de irrigação.  PRADO, G. DO; COLOMBO, A. SPRINKLER WATER DISTRIBUTION COMPOSITIONS  2 ABSTRACT This paper described a procedure to compose a sprinkler pattern for a sprinkler that operates with two nozzles. To compose the pattern, discharge values and patterns of the PLONA-RL250 sprinkler were determined at the sprinkler test bench of the Universidade Federal de Lavras, in Lavras/MG. The tests were conducted with all possible combinations using 14mm and28 mmmain nozzles and the 5, 6 and7 mmauxiliary nozzles as well as with each nozzle functioning individually. Five working pressures (294, 392, 490, 588 and 686 kPa) were used for each nozzle configuration. In the pattern composition process, by adjusting the main and auxiliary nozzle discharges operating individually, and by adjusting  the sprinkler discharge operating with the corresponding pair of main and auxiliary nozzles, it was verified that the average determination coefficient was 88.57% between the dimensionless water application rate of the composed and pair patterns. In the adjusted linear relation, between the uniformity values of a travel irrigation machine obtained from the composed and pair patterns, the inclination was 44° 12' with an average relative error of 2.34%. These results show that the procedure to compose a sprinkler pattern for sprinklers does not influence significantly the water application uniformity of sprinklers. KEY WORDS: sprinkler nozzles, sprinkler flow rate, irrigation uniformity

scholarly journals Experimental Study of Combined Effects of Gamma and Laser Radiations on the Properties of Silicate Glass Materials

2015 ◽  
Vol 3 (3) ◽  
pp. 39-45
Author(s):  
R. T. Khaydarov ◽  
H. B. Beisinbaeva ◽  
R. R. Khaydarov ◽  
F. R. Tojinazarov ◽  
G. R. Berdiyorov ◽  
...  
Keyword(s):  
Experimental Study ◽  
Silicate Glass ◽  
Combined Effects
Sign in / Sign up

Export Citation Format

Share Document