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.

Prying action in bolted steel circular flange connections

2006 ◽  
Vol 33 (4) ◽  
pp. 497-500
Author(s):  
Cindy Kumalasari ◽  
Yongcong Ding ◽  
Murty K.S Madugula
Keyword(s):  
Experimental Investigation ◽  
Test Data ◽  
Tensile Force ◽  
American Institute ◽  
Bolted Connections ◽  
Canadian Institute ◽  
Steel Construction ◽  
Prying Action ◽  
Communication Towers

Both the Canadian Institute of Steel Construction (CISC) Handbook of Steel Construction and the American Institute of Steel Construction (AISC) Manual of Steel Construction discuss prying action in tee-type and angle-type connections subjected to tensile force, but no guidance is provided for determining the prying force in bolted steel circular flange connections. However, such connections are very common in leg members of guyed lattice communication towers. To determine the magnitude of the prying forces in such connections, an experimental investigation was conducted on 10 bolted steel circular flange connections. On the basis of the test data, it is proposed that for use with equations in the CISC handbook and AISC manual, the length of the flange tributary to each bolt (bolt pitch) be taken as the circumference of the bolt circle divided by the number of bolts.Key words: bolt pitch, bolted connections, circular flange, prying action, tensile force.

Design and Analysis of Flanged Skirt Splices for Tall Pressure Vessel Towers

2014 ◽  
Author(s):  
Radoslav Stefanovic ◽  
Peter Ranieri ◽  
Jose I. Dorado ◽  
George Miller
Keyword(s):  
Pressure Vessel ◽  
High Strength ◽  
Construction Site ◽  
American Institute ◽  
Specific Design ◽  
Bottom Part ◽  
Canadian Institute ◽  
Steel Construction ◽  
Impossible Task

Pressure vessel towers used in the petrochemical and chemical industry are designed to accommodate numbers of internals including trays and beds resulting in tall vertical structures. Transportation of tall towers from the fabrication shop to the construction site presents challenges that can result in high transportation costs or a logistically impossible task of moving the vessel. One of the solutions to this problem is to shorten the tower for transport by cutting part of the tower skirt and welding it in the field. Depending on the location, welding on site can be expensive, labour intensive and may cause problems in the quality of the weld and the tower being out of level. Using a flanged skirt connection will reduce the field labour spent on connecting the bottom part of the skirt to the rest of the vessel. The challenge that lies in front of designers is that the current codes and available literature do not give a specific design and calculation guidance for implementing such a solution. This paper looks at different analytical methods to be used for the design of a skirt splice. Methods provided by Jawad and Farr, the Canadian Institute of Steel Construction, the American Institute of Steel Construction, and the Peterson Method from the European Commission’s High-Strength Tower in Steel for Wind Turbines (HISTWIN) are analyzed. Based on this analysis, the most optimal and safe design and fabrication methodology for implementing a Flanged Skirt Connection is proposed.

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.

Experimental basis for the effective length factors of steel solid round cross-braced diagonals in CSA Standard S37-01

2002 ◽  
Vol 29 (3) ◽  
pp. 430-435
Author(s):  
Yongcong Ding ◽  
Kalid S Jaboo ◽  
Yean Sun ◽  
Murty K.S Madugula
Keyword(s):  
Effective Length ◽  
Test Results ◽  
Experimental Basis ◽  
Failure Loads ◽  
Lattice Tower ◽  
Communication Towers ◽  
Round Cross ◽  
Compressive Resistance

The effective length factors for steel solid round diagonals in all-welded communication towers are investigated in this paper to provide experimental basis for the relevant clauses in CSA Standard S37-01. The results of a total of 31 all-welded lattice tower specimens with three types of cross-braced diagonals are presented. The failure loads for these members were determined from the maximum axial strains measured during the tests. The effective length factors were then back-calculated from the experimental failure loads using the compressive resistance formulas. The test results showed that even the significantly lower effective length factors specified in CSA S37-01, compared to CSA S37-94, are still conservative.Key words: all-welded towers, communication towers, cross-bracing, effective length factors, solid round steel diagonals.

Design and Research on Mechanical Properities of New Type Low Modulus Biomedical Metastable β Titanium Alloy

2011 ◽  
Vol 311-313 ◽  
pp. 1667-1672
Author(s):  
Shuang Jin Liu ◽  
Fen Fei Cai ◽  
Chun Xiang Cui ◽  
Xun Yao ◽  
Li Chen Zhao
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
Biomedical Applications ◽  
Design Method ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Test Results ◽  
Biomechanical Compatibility ◽  
Low Modulus ◽  
New Type

One new type metastable β-titanium-alloy for biomedical applications Ti-25Nb-2Mo-4Zr (wt %) with lower elastic modulus was designed based on the d-electron alloy design method and prepared in this study. The microstructure and basic mechanical properties of designed alloy were investigated in this paper. The test results show that the Yang’s modulus is 65GPa and the tensile strength is 863MPa of designed alloy after solution treatment at 700°C for 0.5 h; the Yang’s modulus is 68GPa and the tensile strength is 1032MPa for the designed alloy after aging treatment at 500°C for 2 h. The designed alloy with lower Yang’s modulus is expected to have good prospects for implant biomaterials for its excellent biomechanical compatibility.

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.

Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Normal Concrete ◽  
Astm Method ◽  
Additive Type ◽  
Composition Variation ◽  
Compressive Strength Of Concrete

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.

scholarly journals Practical Prediction Models of Tensile Strength and Reinforcement-Concrete Bond Strength of Low-Calcium Fly Ash Geopolymer Concrete

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 875
Author(s):  
Chenchen Luan ◽  
Qingyuan Wang ◽  
Fuhua Yang ◽  
Kuanyu Zhang ◽  
Nodir Utashev ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Bond Strength ◽  
Prediction Models ◽  
Splitting Tensile Strength ◽  
Geopolymer Concrete ◽  
Structural Factors ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Low Calcium

There have been a few attempts to develop prediction models of splitting tensile strength and reinforcement-concrete bond strength of FAGC (low-calcium fly ash geopolymer concrete), however, no model can be used as a design equation. Therefore, this paper aimed to provide practical prediction models. Using 115 test results for splitting tensile strength and 147 test results for bond strength from experiments and previous literature, considering the effect of size and shape on strength and structural factors on bond strength, this paper developed and verified updated prediction models and the 90% prediction intervals by regression analysis. The models can be used as design equations and applied for estimating the cracking behaviors and calculating the design anchorage length of reinforced FAGC beams. The strength models of PCC (Portland cement concrete) overestimate the splitting tensile strength and reinforcement-concrete bond strength of FAGC, so PCC’s models are not recommended as the design equations.

scholarly journals Absorption and Strength Properties of Short Carbon Fiber Reinforced Mortar Composite

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 300
Author(s):  
Md. Safiuddin ◽  
George Abdel-Sayed ◽  
Nataliya Hearn
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Absorption ◽  
Carbon Fibers ◽  
Strength Properties ◽  
Fiber Content ◽  
Test Results ◽  
Air Content ◽  
Entrapped Air ◽  
Short Carbon

This paper presents the water absorption and strength properties of short carbon fiber reinforced mortar (CFRM) composite. Four CFRM composites with 1%, 2%, 3%, and 4% short pitch-based carbon fibers were produced in this study. Normal Portland cement mortar (NCPM) was also prepared for use as the control mortar. The freshly mixed mortar composites were tested for workability, wet density, and entrapped air content. In addition, the hardened mortar composites were examined for compressive strength, splitting tensile strength, flexural strength, and water absorption at the ages of 7 and 28 days. The effects of different carbon fiber contents on the tested properties were observed. Test results showed that the incorporation of carbon fibers decreased the workability and wet density, but increased the entrapped air content in mortar composite. Most interestingly, the compressive strength of CFRM composite increased up to 3% carbon fiber content and then it declined significantly for 4% fiber content, depending on the workability and compaction of the mortar. In contrast, the splitting tensile strength and flexural strength of the CFRM composite increased for all fiber contents due to the greater cracking resistance and improved bond strength of the carbon fibers in the mortar. The presence of short pitch-based carbon fibers significantly strengthened the mortar by bridging the microcracks, resisting the propagation of these minute cracks, and impeding the growth of macrocracks. Furthermore, the water absorption of CFRM composite decreased up to 3% carbon fiber content and then it increased substantially for 4% fiber content, depending on the entrapped air content of the mortar. The overall test results suggest that the mortar with 3% carbon fibers is the optimum CFRM composite based on the tested properties.

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