Mechanical Property of FRP Bar and Design Method of Hybrid FRP Bar

2009 ◽  
Vol 620-622 ◽  
pp. 339-342
Author(s):  
Xin Sheng Xu ◽  
Ning Zhang ◽  
Tao Ji
Keyword(s):  
Mechanical Property ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Design Method ◽  
Production Method ◽  
Test Method ◽  
Test Results ◽  
High Durability ◽  
Steel Bar ◽  
Frp Bar

The paper described the detailed design and production method of the FRP bar and the anchorage device, and it also introduced the test method of mechanical properties on the tensile strength, elastic modulus and the rate of elongation of the FRP bar. Moreover, it conducted statistical analysis into test results and put forward the mechanical property index for structural design of the FRP bar concrete. Test results indicated that stress-strain relation of the FRP bar presented linear variation. FRP bar is superior to steel bar concerning high tensile strength-quality ratio and high durability, the elastic modulus and the rate of elongation of the FRP bar are also less than those of the steel bar, it is practicable to use FRP bar as a new type of tensile material in concrete structures. And then, it put forward design ideas of the hybrid FRP bar by a series of analysis on the hybrid effect and the ductility of the hybrid FRP bar.

Test Research on Mechanical Property of GFRP Bolt under Freeze-Thaw Cycle Conditions

2012 ◽  
Vol 531-532 ◽  
pp. 689-694
Author(s):  
Xie Xing Tang ◽  
Xiao Yong Luo ◽  
Qi Sun ◽  
Ya Chuan Kuang
Keyword(s):  
Mechanical Property ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Test Results ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Times

In this paper, GFRP bolts in diameter of 25mm are tested through freeze-thaw cycle by 50, 100 and 150 times to study their change law of appearance, weight, strength and elastic modulus. As reflected from the test results, after the freeze-thaw cycle, the appearance and weight of GFRP bolts are basically not changed. As the freeze-thaw cycle increases from 50 times to 100 times, the strength of bolts decreases gradually. After 50, 100 and 150 times of freeze-thaw cycle, the ultimate tensile strength of bolt decreases by 2.82%, 4.35% and 8.84%, respectively. During the process that the times of freeze-thaw cycle increase from 50 to 100, the elastic modulus of GFRP bolts grows gradually. After 50, 100 and 150 times of freeze-thaw cycle, the elastic modulus increases by 1.42%, 2.68% and 3.92%, respectively. The freeze-thaw cycle leads to embrittlement of GFRP materials and weakness of ductility, while not obviously.

Experimental Method Study on Tensile Properties of GFRP Bar

2013 ◽  
Vol 438-439 ◽  
pp. 365-368
Author(s):  
Fei Mo ◽  
Pu Zhang ◽  
Dan Ying Gao ◽  
Yu Yang Pang ◽  
Ke Zhao
Keyword(s):  
Tensile Strength ◽  
Large Diameter ◽  
Testing Machine ◽  
Test Method ◽  
Internal Thread ◽  
Test Results ◽  
Anchor Length ◽  
Gfrp Bar ◽  
Frp Bar ◽  
Frp Bars

The GFRP bar has good mechanical properties and durability, but it is hard to test the tensile strength of large diameter FRP bar. Its test method given by ACI is too conservative, especially for large diameter FRP bar, and the length of test specimen will be too long and beyond the range of most testing machine. This article tested the tensile strength of GFRP bar using new methods, meanwhile, analyzed its stress distribution along the length of the specimens. The test results show that the use of bond anchor with steel plug or internal thread to measure the tensile strength of GFRP bar is feasible, and it can reduce the free length and the anchor length of the specimens, thus simplifying the test method of the tensile strength of FRP bars.

Effect of Carbon Black Reinforcing Fillers on Mechanical Properties of NBR Materials Used for the Progressing Cavity Pump

2015 ◽  
Vol 750 ◽  
pp. 339-344 ◽  
Author(s):  
Long Pan ◽  
Jin Zhu Tan ◽  
Liu Fei Fan ◽  
Xue Mei Han
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Black ◽  
Heat Resistance ◽  
Tear Strength ◽  
Resistance Property ◽  
Reinforcing Fillers ◽  
Materials Used

Three kinds of reinforcing fillers (i.e. carbon black N330, carbon black N880 and carbon-white) were used to study effect of the reinforcing fillers on the mechanical properties of NBR materials. The NBR materials with various reinforcing fillers were fabricated, and the mechanical property tests were performed in this work. The results show that the carbon black N330 made the NBR material have better tensile strength, hardness, elongation and compression elastic modulus compared to the carbon black N880 and the carbon-white, while the carbon-white made NBR material have better heat resistance, tear strength and elongation compared to the carbon black N330 and the carbon black N880. In addition, the tensile strength, tear strength, elongation and the heat resistance property of the NBR materials increased significantly with the increase of the carbon-white, but the compression elastic modulus decreased with the increase of the carbon-white.

scholarly journals An Image-Based Impact Test for the High Strain Rate Tensile Properties of Brittle Materials

2018 ◽  
Vol 183 ◽  
pp. 02042
Author(s):  
Lloyd Fletcher ◽  
Fabrice Pierron
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
High Strain Rate ◽  
Strain Rate ◽  
Stress Wave ◽  
High Strain ◽  
Brittle Materials ◽  
Test Method ◽  
Strain Rates ◽  
High Strain Rates

Testing ceramics at high strain rates presents many experimental diffsiculties due to the brittle nature of the material being tested. When using a split Hopkinson pressure bar (SHPB) for high strain rate testing, adequate time is required for stress wave effects to dampen out. For brittle materials, with small strains to failure, it is difficult to satisfy this constraint. Because of this limitation, there are minimal data (if any) available on the stiffness and tensile strength of ceramics at high strain rates. Recently, a new image-based inertial impact (IBII) test method has shown promise for analysing the high strain rate behaviour of brittle materials. This test method uses a reflected compressive stress wave to generate tensile stress and failure in an impacted specimen. Throughout the propagation of the stress wave, full-field displacement measurements are taken, from which strain and acceleration fields are derived. The acceleration fields are then used to reconstruct stress information and identify the material properties. The aim of this study is to apply the IBII test methodology to analyse the stiffness and strength of ceramics at high strain rates. The results show that it is possible to identify the elastic modulus and tensile strength of tungsten carbide at strain rates on the order of 1000 s-1. For a tungsten carbide with 13% cobalt binder the elastic modulus was identified as 516 GPa and the strength was 1400 MPa. Future applications concern boron carbide and sapphire, for which limited data exist in high rate tension.

Tensile strength of bolted ring-type splices of solid round leg members of guyed communication towers

2005 ◽  
Vol 32 (3) ◽  
pp. 595-600
Author(s):  
Cindy Kumalasari ◽  
Lihong Shen ◽  
Murty K.S Madugula ◽  
Faouzi Ghrib
Keyword(s):  
Tensile Strength ◽  
Design Method ◽  
Test Results ◽  
American Institute ◽  
Ring Type ◽  
Canadian Institute ◽  
Steel Construction ◽  
Failure Loads ◽  
Guyed Towers ◽  
Communication Towers

Bolted ring-type splices are very common in guyed communication towers using solid round legs 65 mm in diameter or smaller, but there is no guidance provided in either the Canadian Institute of Steel Construction Handbook of steel construction or the American Institute of Steel Construction Manual of steel construction for the design of such splices. Eighteen ring-type splices (three groups of six specimens each) were tested and experimental failure loads were determined. Based on the test results, it is concluded that it is unsafe to ignore the eccentricity of the splice. It is suggested that the load at first yield be conservatively taken as the strength of the splice. A simplified design method is proposed that takes into account the eccentricity of the splice, and the results from the proposed method agree closely with the experimental values.Key words: eccentricity of splice, guyed towers, ring-type splice, solid round legs, tensile strength.

Behavior of Continuous FRP Rectangular Spirals as Shear Reinforcement for Concrete Beams

2011 ◽  
Vol 418-420 ◽  
pp. 307-312
Author(s):  
Shi Yong Jiang ◽  
Bing Hong Li ◽  
Qian Hua Shi ◽  
Xian Qi Hu
Keyword(s):  
Experimental Investigation ◽  
Tensile Strength ◽  
Concrete Beams ◽  
Concrete Strength ◽  
Concrete Structures ◽  
Test Method ◽  
Test Results ◽  
Shear Reinforcement ◽  
Straight Portion ◽  
Embedment Length

The replacement of steel stirrups with FRP stirrups in concrete structures can significantly improve the durability under severe environmental conditions, increase the service life of the structure. In some cases where the application of traditional concrete structures is restricted, such as structures that require the environment without magnetic and electric interferences, the best way is to use nonmetallic materials. Considering the unique properties compared with traditional reinforcements, FRP reinforcements is very suitable in such cases. This paper discussed the behavior of FRP stirrups used as shear reinforcement for concrete structures, continuous FRP rectangular spirals, a type of FRP stirrups, was used in the experimental investigation. Inspired by the test method suggested by ACI Committee 440, L shape specimen and U shape specimen are designed to test the tensile strength of continuous FRP rectangular spirals. Through the analysis of test results, it is indicated that the strength of the bent portion of FRP spirals is significantly lower than that of the straight portion, and the strength of FRP spirals would increase as the concrete strength or the embedment length of the bent portion increased. The loading mechanism of continuous FRP rectangular spirals embedded in concrete beams can be better represented by U shape specimen compared with L shape specimens, it is suggested by the author that the U shape specimen can be use when the dimension of FRP stirrups or spirals does not meet the requirements of ACI Committee 440 test method.

Investigation of a combined failure mode for screw anchors under tension

2020 ◽  
Vol 23 (13) ◽  
pp. 2803-2812
Author(s):  
Zhao Chen ◽  
Somayeh Nassiri ◽  
Anthony Lamanna
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Regression Model ◽  
Failure Mode ◽  
Design Method ◽  
Test Results ◽  
Capacity Design ◽  
Tension Tests ◽  
Combined Mode ◽  
Combined Failure

A modified concrete capacity design method is available to predict the ultimate tensile strength ( Nu) of screw anchors. Screw anchors commonly fail in a combination of concrete breakout and pullout modes. This combined mode is not distinguished from the breakout mode in the modified concrete capacity design method, which may cause confusions to designers. To investigate the Nu of the combined mode ( Ncomb), this study included 144 unconfined tension tests on screw anchors from three manufacturers in three diameters and two effective embedment depths ( hef) per diameter. Approximately 80% of the tested anchors failed in the combined mode. The differences in Ncomb among the three manufacturers were insignificant despite their varied thread design. Ncomb was found to be linearly correlated to the parameter hef 1.3 but was found independent of the anchor diameter. A regression model was developed to specifically predict Ncomb. The model showed a good fit with the test results.

Flexural Strength Behavior of Composite UHPFC - Existing Concrete

2013 ◽  
Vol 701 ◽  
pp. 32-36 ◽  
Author(s):  
Bassam A. Tayeh ◽  
Badorul Hisham Abu Bakar ◽  
Megat Azmi Megat Johari ◽  
A.M. Zeyad
Keyword(s):  
Flexural Strength ◽  
High Performance ◽  
Substrate Surface ◽  
Surface Preparation ◽  
Test Method ◽  
Test Results ◽  
Substrate Roughness ◽  
Conventional Concrete ◽  
High Durability ◽  
High Performance Fiber

Ultra high performance fiber concrete (UHPFC) is an advanced formula concrete that is proven to be more superior than conventional concrete because it embrace the qualities of steel and concrete. Therefore UHPFC properties which include high durability and strength are fully exploited in the research of rehabilitation and strengthening in concrete and even non-concrete structures. This article presents the findings of an experimental study carried out to examine the bonding strength behaviour between normal concrete (NC) substrate and UHPFC as a repair material, under flexural strength test by using third-point loading beam test method. Three types of NC substrate surface preparation were used: as-cast (without surface preparation) as a reference, wire-brushed, and sand-blasted. The flexural test results clearly indicated that all failures occurred through the NC substrate and no de-bonding was observed in the interface between NC substrate and UHPFC. The results of the flexural strength confirmed that adhesion bond strength between NC substrate and UHPFC was stronger than the substrate regardless, the substrate roughness. This proves that UHPFC is able to link and bond strongly with the substrate.

scholarly journals Mechanical properties of blueberry stems

2018 ◽  
Vol 64 (No. 4) ◽  
pp. 202-208
Author(s):  
Margus Arak ◽  
Kaarel Soots ◽  
Marge Starast ◽  
Jüri Olt
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Structural Parameters ◽  
Tensile Tests ◽  
Measuring Instrument ◽  
Test Results ◽  
Average Value ◽  
Agricultural Machines

In order to model and optimise the structural parameters of the working parts of agricultural machines, including harvesting machines, the mechanical properties of the culture harvested must be known. The purpose of this article is to determine the mechanical properties of the blueberry plant’s stem; more precisely the tensile strength and consequent elastic modulus E. In order to achieve this goal, the measuring instrument Instron 5969L2610 was used and accompanying software BlueHill 3 was used for analysing the test results. The tested blueberry plant’s stems were collected from the blueberry plantation of the Farm Marjasoo. The diameters of the stems were measured, test units were prepared, tensile tests were performed, tensile strength was determined and the elastic modulus was obtained. Average value of the elastic modulus of the blueberry (Northblue) plant’s stem remained in the range of 1268.27–1297.73 MPa.

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