Experimental Study on Post Fire Tensile Properties of Reinforcing Rebars Connected by Grout-Filled Splice Sleeves

2018 ◽  
Vol 773 ◽  
pp. 305-310
Author(s):  
Yong Jun Liu ◽  
Qing Hong Zeng ◽  
Hong Ru Liu ◽  
Shuo Xun Wang
Keyword(s):  
Tensile Properties ◽  
Ultimate Load ◽  
Reference Group ◽  
Testing Machine ◽  
Effect Of Temperature ◽  
Reinforcing Bars ◽  
Load Bearing ◽  
Standard Fire ◽  
Structural Behaviors ◽  
Steel Rebars

This paper presents some experimental results of tensile properties of reinforcing bars spliced by grout-filled coupling sleeves after exposed to fires to identify the effect of temperature histories on tensile properties of spliced reinforcing bars, which provide a useful base for assessing structural behaviors of precast reinforced concrete buildings damaged by fires. A spliced rebar system investigated in this paper consists of two equal-diameter steel reinforcing bars with 25mm diameter and a straight coupling sleeve with 55mm outer and 42mm inner diameters. As a result, the thickness of grout between internal steel bars and outer sleeves are 8.5mm. Five test specimens are manufactured in identical technology and divided into three groups. First group is reference group consist of just one specimen which is not exposed to fire. Second and third groups consist of two specimens that are exposed to ISO 834 standard fire in furnace for 15 and 25 minutes respectively. The temperature-time curves of grout between rebars and sleeves are measured via thermocouples embedded in grout. Subsequently, a universal testing machine is used to test the ultimate load bearing capacities of five specimens. Test results demonstrate that ultimate load bearing capacities of steel rebars spliced by grout-filled sleeves are considerably reduced due to fire damaged grout.

scholarly journals Numerical Analysis on Tensile Properties of Grout-filled Splice Sleeve Rebars under ISO 834 Standard Fire

2018 ◽  
Vol 38 ◽  
pp. 03036 ◽  
Author(s):  
Yong Jun Liu ◽  
Chao Li ◽  
When Jun Zhou
Keyword(s):  
Tensile Properties ◽  
Fire Resistance ◽  
Tensile Load ◽  
Load Ratio ◽  
Reinforcing Bars ◽  
Element Analysis ◽  
Standard Fire ◽  
Axial Tensile ◽  
Stress Changes ◽  
Steel Bars

This paper presents some numerical simulation results of tensile properties of reinforcing bars spliced by grout-filled coupling sleeves under fire conditions to identify the effect of load ratio on fire resistance time of spliced reinforcing bars, which provide a useful base for predicting structural behaviors of pre-cast reinforced concrete buildings in fires. A spliced rebar system investigated in this paper consists of two equal-diameter steel reinforcing bars with 25mm diameter and a straight coupling sleeve with 50mm outer and 45mm inner diameters. As a result, the thickness of grout between steel bars and sleeves are 20mm. Firstly, the temperature distributions in steel bars connected by grout- filled coupling sleeves exposed to ISO 834 standard fire were calculated utilizing finite element analysis software ANSYS. Secondly, the stress changes in heated steel bars connected by grout-filled coupling sleeves under different constant tensile loads were calculated step by step until the rebar system failed due to fire. Thus, the fire resistant time of rebar spliced by grout-filled coupling sleeves under different axial tensile loads can be determined, further, the relationship between fire resistance time and axial tensile loads ratio can could be obtained. Finally, the fire resistant times versus axial tensile load ratios curve of grout-filled splice sleeve rebars exposed to ISO 834 standard fire is presented.

The Effect of Temperature on the Tensile Properties of Steel 0Cr18Ni9

2010 ◽  
Vol 654-656 ◽  
pp. 194-197
Author(s):  
Wei Fen Li ◽  
Wei Niu ◽  
Zhi Ming Hao ◽  
Ming Hai Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Tensile Properties ◽  
Tensile Testing ◽  
Testing Machine ◽  
Effect Of Temperature ◽  
Tensile Testing Machine ◽  
Increasing Temperature

Experiments of tensile mechanical properties of steel 0Cr18Ni9 are done on the MTS 810 tensile testing machine, and the temperature range is from 20°C to 1200°C. The stress vs. strain curves are obtained. Results show that the elastic modulus, yield stress and tensile strength decrease with increasing temperature .Based on the experiment results, the functions of the elastic modulus, yield strength and tensile strength versus temperature are represented by polynomial.

STRENX 700

Alloy Digest ◽  
2017 ◽  
Vol 66 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Physical Properties ◽  
Structural Steel ◽  
Tensile Properties ◽  
High Strength ◽  
Load Bearing ◽  
Minimum Yield

Abstract Strenx 700 is a high-strength structural steel with a minimum yield strength of 650–700 MPa (94–102 ksi) depending on thickness. Strenx 700 meets the requirements of EN 10 025-6 for the S690 grade and thicknesses. Typical applications include demanding load-bearing structures. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness. It also includes information on surface qualities as well as forming, machining, and joining. Filing Code: SA-779. Producer or source: SSAB Swedish Steel Inc..

scholarly journals The energy absorption behavior of novel composite sandwich structures reinforced with trapezoidal latticed webs

2021 ◽  
Vol 60 (1) ◽  
pp. 503-518
Author(s):  
Juan Han ◽  
Lu Zhu ◽  
Hai Fang ◽  
Jian Wang ◽  
Peng Wu
Keyword(s):  
Bearing Capacity ◽  
Energy Absorption ◽  
Sandwich Structure ◽  
Ultimate Load ◽  
Sandwich Structures ◽  
Elastic Displacement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Composite Sandwich ◽  
Composite Sandwich Structures

Abstract This article proposed an innovative composite sandwich structure reinforced with trapezoidal latticed webs with angles of 45°, 60° and 75°. Four specimens were conducted according to quasi-static compression methods to investigate the compressive behavior of the novel composite structures. The experimental results indicated that the specimen with 45° trapezoidal latticed webs showed the most excellent energy absorption ability, which was about 2.5 times of the structures with vertical latticed webs. Compared to the traditional composite sandwich structure, the elastic displacement and ultimate load-bearing capacity of the specimen with 45° trapezoidal latticed webs were increased by 624.1 and 439.8%, respectively. Numerical analysis of the composite sandwich structures was carried out by using a nonlinear explicit finite element (FE) software ANSYS/LS-DYNA. The influence of the thickness of face sheets, lattice webs and foam density on the elastic ultimate load-bearing capacity, the elastic displacement and initial stiffness was analyzed. This innovative composite bumper device for bridge pier protection against ship collision was simulated to verify its performance. The results showed that the peak impact force of the composite anti-collision device with 45° trapezoidal latticed webs would be reduced by 17.3%, and the time duration will be prolonged by about 31.1%.

Strength of side-to-side and step-cut repairs in tendon transfers: biomechanical testing of porcine flexor tendons

2020 ◽  
Vol 45 (10) ◽  
pp. 1061-1065
Author(s):  
Eivind Strandenes ◽  
Peter Ellison ◽  
Anders O. Mølster ◽  
Nils R. Gjerdet ◽  
Irene O. Moldestad ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Testing Machine ◽  
Biomechanical Testing ◽  
Maximum Load ◽  
Side Group ◽  
Tendon Transfers ◽  
Flexor Tendons ◽  
Active Mobilization ◽  
The Difference

The aim of the study was to compare side-to-side with step-cut repairs to determine how much of the width it is possible to remove and still keep the repair strong enough to start active mobilization. Porcine flexor tendons were used to create side-to-side, one-third step-cut and half step-cut repairs. There were 15 repairs in each group. The tensile properties of the constructs were measured in a biomechanical testing machine. All repairs failed by the sutures splitting the tendon longitudinally. The maximum load and stiffness were highest in the side-to-side group. Our findings suggest that the half step-cut repair can withstand the forces exerted during active unrestricted movement of the digits in tendons of this size. The advantage of the step-cut repair is reduced bulkiness and less friction, which might compensate for the difference in strength.

Properties of Hard Rubber. XIX. Effect of Temperature on Cross-Breaking Strength and Elongation

1947 ◽  
Vol 20 (2) ◽  
pp. 525-526
Author(s):  
W. H. Willott
Keyword(s):  
Breaking Strength ◽  
Testing Machine ◽  
Effect Of Temperature ◽  
Loading Test ◽  
Standard Size ◽  
Test Pieces ◽  
The Cross ◽  
Hot Weather ◽  
Electric Radiator ◽  
Usual Order

Abstract In a series of cross-breaking tests carried out on hard rubber during hot weather, the values of the breaking elongation were higher than was expected, although the cross-breaking strength was of the usual order. It was thought that the high temperature might account for these results by making the hard rubber more plastic. The following experiments were, therefore, performed to investigate the effect of small changes of temperature, such as are encountered at different times of the year, on the cross-breaking strength and elongation. Test-pieces of standard size (75 × 25 × 5 mm.) were cut from a sheet of hard rubber of the composition: 68 per cent rubber, 32 per cent sulfur, which had been vulcanized for 5 hours at 155° C. They were immersed in a beaker of water and kept at the required temperature for about 15 minutes, when they were judged to have attained a steady temperature. The tests were carried out on an Avery fabric-testing machine fitted with special clamps to give a three-point loading test, the distance between the supporting knife-edges being 50.4 mm. (2 in.). These clamps were heated to the temperature of the specimens by means of an electric radiator. The specimens were tested as soon as possible after they had been removed from the water, so that the change of temperature during the test was reduced as far as possible. The standard conditions already laid down, were observed.

Dynamic Behaviour of Reinforcing Steel Bars in Tension

2011 ◽  
Vol 82 ◽  
pp. 86-91 ◽  
Author(s):  
Ezio Cadoni ◽  
Matteo Dotta ◽  
Daniele Forni ◽  
Nicoletta Tesio
Keyword(s):  
Testing Machine ◽  
Maximum Load ◽  
Gauge Length ◽  
Strain Rates ◽  
Reinforcing Bars ◽  
Static Tests ◽  
Split Hopkinson Tensile Bar ◽  
Steel Bars ◽  
Split Hopkinson ◽  
Reinforced Steel

In this paper the preliminary results of the tensile behavior of reinforced steel in a large range of strain rates are presented. Tensile testing at several strain rates, using different experimental set-ups, was carried out. For the quasi-static tests a universal electromechanical testing machine with the maximum load-bearing capacity of 50 kN was used, while for the intermediate and high-strain rate regimes a hydro-pneumatic apparatus and a JRC-Split Hopkinson Tensile Bar respectively were used. The target strain rates were set at the following five levels: 10-3, 30, 250, 500, and 1000 1/s. The specimens used in this research were round samples having 3mm in diameter and 5mm of gauge length obtained from reinforcing bars. Finally, the material parameters for Cowper-Symonds and Johnson-Cook models were determined.

scholarly journals EXPERIMENTAL FINDING OF FRACTURE TOUGHNESS CHARACTERISTICS AND THEORETICAL MODELING OF CRACK PROPAGATION PROCESSES IN CARBON FIBER SAMPLES UNDER CONDITIONS OF ADDITIVE PRODUCTION

2019 ◽  
Vol 16 (33) ◽  
pp. 325-336
Author(s):  
V. N. DOBRYANSKIY ◽  
L. N. RABINSKIY ◽  
O. V. TUSHAVINA
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Crack Resistance ◽  
Tensile Properties ◽  
Practical Importance ◽  
Effect Of Temperature ◽  
Zone Model ◽  
Cohesive Elements ◽  
Damage Development ◽  
Mechanical Tensile

The relevance of the problem stated in this article is that the development of aerospace technology increased the demand for good quality materials. An important issue is ensuring durability in conditions of longterm loads and in conditions of damage development. One of the criteria that ensure the toughness of the material is crack resistance. The aim of the work is to study the interlayer crack resistance (fracture toughness) under loading under conditions of separation and transverse shear, interlayer strength, as well as the effect of temperature on interlayer strength, mechanical tensile properties. A comparison of the values of interlayer crack resistance GIС (separation) and GIIС (shear) and of mechanical tensile properties and interlayer strength of carbon fiber samples is made. The main methods for studying this problem were the short-beam method, the DCB method, the ENF method. The results of the experimental data were compared with modeling the processes of the appearance and development of cracks in the finite element complexes ABAQUS and Ansys based on the VVCT models, cohesive elements. Deviations from the experiment were found and conclusions were drawn that the point of application of the load had to be shifted from the edge of the sample, which will reduce the initial separation and increase the stiffness of the sample. Due to the fact that the cohesion zone model is very sensitive to input parameters, it is necessary to know many parameters and take into account a large number of factors. The practical importance of this work is to show how to use the VCCT model to obtain the critical load of the germination of the first crack. The research technique can be used for further experiments, including simulation further stratification with low inaccuracy.

scholarly journals The Effect of Imidazolium-Based Ionic Liquids on the Tensile Properties of Gellan Gum/KCF Biocomposite Films - A Prelude Study

2021 ◽  
pp. 1-10
Author(s):  
Ahmad Adlie Shamsuri ◽  
Khalina Abdan ◽  
Tatsuo Kaneko
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Tensile Properties ◽  
Testing Machine ◽  
Tensile Modulus ◽  
Gellan Gum ◽  
Mixed Solution ◽  
Test Results ◽  
Biocomposite Films ◽  
Biocomposite Film

In this prelude study, the gellan gum/kenaf core fiber (KCF) biocomposite films were fabricated with the addition of imidazolium-based ionic liquids such as 1-butyl-3-methylimidazolium chloride (Bmim Cl), 1,3-dimethylimidazolium methylsulphate (Dmim MeSO4), 1-ethyl-3-methylimidazolium acetate (Emim Ac), and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (Emim OTf). The fabrication of the biocomposite films was carried out by mixing KCF and the ionic liquids in an aqueous solution, followed by dissolution of gellan gum in the same solution at a temperature of 90°C. The mixed solution was gelled at room temperature, and the formed gel was dried in an oven at 40°C for 48 hours to obtain a freestanding biocomposite film. The fabricated films were characterized by using a universal testing machine to acquire tensile properties. The tensile test results indicated that the biocomposite film added with Emim Ac possesses a higher tensile extension at maximum (up to 24%) than the biocomposite film without ionic liquid (added with glycerol). In addition, the biocomposite film added with Emim OTf has a higher tensile modulus at maximum (up to 758%) compared to the biocomposite film without ionic liquid. In conclusion, the tensile properties of the gellan gum/KCF biocomposite films can be improved with the addition of Emim-based ionic liquids with different counter anions.

Experimental Study on Tensile Properties of Sugarcane Leaves

2021 ◽  
Vol 37 (4) ◽  
pp. 615-621
Author(s):  
Jing Bai ◽  
Shaochun Ma ◽  
Jiwei Hu ◽  
Yi Wei ◽  
Fenglei Wang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Tensile Properties ◽  
Tensile Force ◽  
Testing Machine ◽  
Longitudinal Direction ◽  
Leaf Sheath ◽  
List Type ◽  
Factors Affecting ◽  
Strong Linear Correlation ◽  
Tensile Forces

Highlights This article focuses on the tensile properties of sugarcane leaves. The moisture content and sheath diameter were selected as test factors, and the test index was the stalk-leaf connecting force. The load-displacement curves of stalks and leaves were plotted. Two-way ANOVA was also discussed. Abstract . The tensile properties of sugarcane leaves are critical factors affecting the harvesting quality of sugarcane harvesters. Thus, it is important to investigate the tensile properties of sugarcane stalks and leaves. The selected test factors were leaf moisture content and sheath diameter, and the stalk-leaf connecting force was selected as test index. The tests were conducted with two moisture content levels of 15% and 20%, and three sheath diameters of 22, 26, and 30 mm. The stress-strain curves of stalks and leaves were plotted to show how the tensile force varied during the tensile test. The results showed that there was a strong linear correlation between the stalk-leaf connecting force and diameter of leaf sheath, and the connecting force also increased with the increasing moisture content. In addition, leaf tensile forces in longitudinal direction were much larger than in transverse direction. Two-way ANOVA revealed that both of the moisture contents (A) and sheath diameters (B) had significant effects on the stalk-leaf connecting force (p < 0.01), however, the interaction between A and B was not significant (p > 0.1). This study provides a theoretical reference for the design and improvement of crop dividers of sugarcane harvester. Keywords: Moisture content, Sheath diameter, Stalk-leaf connecting force, Sugarcane leaves, Universal testing machine, Tensile properties.

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