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.

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.

A novel method for determining effective length factors for solid round steel leg members of guyed lattice towers with cross-bracing

2003 ◽  
Vol 30 (4) ◽  
pp. 780-786
Author(s):  
Yongcong Ding ◽  
Faouzi Ghrib ◽  
Sudip Bhattacharjee ◽  
Murty K.S Madugula
Keyword(s):  
Closed Form Solution ◽  
Form Solution ◽  
Effective Length ◽  
Rotational Stiffness ◽  
Element Analysis ◽  
Effective Length Factor ◽  
Novel Method ◽  
Lattice Tower ◽  
Lattice Towers ◽  
Communication Towers

A novel method is presented for determining the effective length factors (K factors) for solid round steel leg (vertical) members in all-welded guyed communication towers with cross-bracing. Deflections due to an arbitrary load were used to determine the restraining moments and rotational stiffness of the legs. Using the closed-form solution for buckling of a column with rotational restraint at both ends, K factors were computed. From the study it is found that the K factors varied from 0.61 to 1.00, depending on the relative sizes of the leg and bracing members. An expression for estimating the effective length factors for solid round steel leg members of all-welded guyed lattice towers with cross-bracing is developed.Key words: cross-bracing, effective length factor (K factor), finite element analysis, guyed lattice tower, solid round steel leg member, welded tower.

Technique to increase the effective length of practical earth electrodes: Simulation and field test results

2013 ◽  
Vol 94 ◽  
pp. 99-105 ◽  
Author(s):  
A. El Mghairbi ◽  
M. Ahmeda ◽  
N. Harid ◽  
H. Griffiths ◽  
A. Haddad
Keyword(s):  
Field Test ◽  
Effective Length ◽  
Test Results

Theoretical and Experimental Research on Joint Slippage Effects of Lattice Angle Steel Tower

2013 ◽  
Vol 477-478 ◽  
pp. 660-665
Author(s):  
Zhang Qi Wang ◽  
Ze Ming Song ◽  
Wen Qiang Jiang
Keyword(s):  
Axial Force ◽  
Numerical Models ◽  
Element Model ◽  
Test Results ◽  
Bolted Joint ◽  
Transmission Tower ◽  
Hybrid Finite Element ◽  
Lattice Tower ◽  
Angle Steel ◽  
Bolt Diameter

In lattice angle steel transmission tower, as the bolt diameter is small and member connection is relatively thin, lower clamping force is commonly used in bolted joint. It is common in lattice tower during full tower tests, joint slippage occur even under design load. However, traditionally trussed beam hybrid finite element model without explicitly considering slippage effects has been widely used in the analysis of the tower. In this paper, the HD-1 tower was experimentally studied under various static load cases, and several numerical models with including joint eccentricity and slippage are established. After comparing the theoretical analysis results and the experimental results, the following conclusions are presented: joint eccentricity almost has not effects on leg member axial force; Among all the studied load cases, joint slippage effects the leg member force most under torsional condition than the other load conditions; Numerical model with including joint slippage effects yield much better axial force results in leg member compared with experimental test results.

scholarly journals Model Tests for Shallow-Water Ship Maneuverability in Three Gorges Reservoir

2015 ◽  
Vol 22 (s1) ◽  
pp. 136-140
Author(s):  
Chuang Cai ◽  
Xinyong Cai ◽  
Yi Li
Keyword(s):  
Shallow Water ◽  
Scale Effect ◽  
Three Gorges Reservoir ◽  
Correction Method ◽  
Model Tests ◽  
Influential Factors ◽  
Three Gorges ◽  
Test Results ◽  
Experimental Basis ◽  
Ship Maneuverability

Abstract This paper conducts calibration tests on the shallow-water maneuverability of 1:100 ship models for the typical navigation fleets in Three Gorges Reservoir. Major influential factors for the maneuverability similitude between models and prototypes and for scale effect were identified. A correction method for model scale was also established through model tests. Test results indicate that, by correcting the model scales of various fleets based on scale effect, the maneuverability indexes K’ (dimensionless of K) and T’ (dimensionless of T) of ship models are suitable for shallow-water tests, and properly reflect the maneuvering characteristics of prototypes. The findings provide an experimental basis for the navigation safety in Three Gorges Reservoir.

Simulation and Numerical Analysis on Anti-Float Anchor by Field Rock and Soil Tests

2014 ◽  
Vol 686 ◽  
pp. 671-675
Author(s):  
Xiang Ling Zhou
Keyword(s):  
Numerical Analysis ◽  
Axial Force ◽  
Field Testing ◽  
Internal Force ◽  
Effective Length ◽  
Test Results ◽  
Future Design ◽  
Anchor Group ◽  
Stress And Deformation ◽  
Rock And Soil

This paper introduces the stress and deformation of anti floating anchor rod and explained the damage. Through field testing and numerical analysis, the article were studied the displacement and internal force of a basement tensile anti float anchor, results showed that: the axial force of bolt tension transfer is top-down transfer, axial force decreases, the stress concentrate on the end. When a force is applied to a certain load, end firstly generate damage, but with the deepening of the axial force, it is greatly reduced, which indicates that the anchor force is an effective length, rather than the longer the anchor pullout force is bigger; anchor group effect is a problem that can not be ignored, because the engineering community for its attention degree is not enough, so that the design of anti floating anchor the lack of a reliable basis, the test results can provide a reference for the future design of anti floating anchor. Prestressed anchors in the tension lock, prestressed loss are regularly.

Influence of the assumed effective length factor on the load carrying capacity of steel angles in compression

1995 ◽  
Vol 22 (6) ◽  
pp. 1171-1177
Author(s):  
Murray C. Temple ◽  
Davide M. Petretta ◽  
Catherine Morand
Keyword(s):  
Principal Axis ◽  
Design Procedure ◽  
Effective Length ◽  
Experimental Program ◽  
Load Carrying Capacity ◽  
Effective Length Factor ◽  
Compression Members ◽  
Load Carrying ◽  
Steel Angles ◽  
Compressive Resistance

Single angle compression members are usually attached by one leg only. In Canada it is common practice when designing such members to neglect the end eccentricities, to assume the angle buckles about the minor principal axis, and to assume an effective length factor of 1.0. Clause 13.3.1 of S16.1 is then used to calculate the compressive resistance. An experimental program was undertaken to determine the effect that the assumed effective length factor has on the compressive resistance of such angles. Eighteen specimens were tested in which the angles were slender or of intermediate length. The effective length factor was assumed to be 1.0, 0.9, or 0.5. It was determined that when there is substantial restraint at the ends of the angles the assumed effective length factor has a very significant effect on the compressive resistance of an angle attached by one leg. Key words: angles, axis of bending, buckling, design procedure, effective length factor.

scholarly journals Balanced and unbalanced welds for angle compression members

1994 ◽  
Vol 21 (3) ◽  
pp. 396-403 ◽  
Author(s):  
Murray C. Temple ◽  
Sherief S. S. Sakla
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Compressive Load ◽  
Tensile Load ◽  
Effective Length ◽  
Load Carrying Capacity ◽  
Compression Members ◽  
Load Carrying ◽  
Compressive Loads ◽  
Compressive Resistance

Angles used as web members in trusses are often welded to the chords with unbalanced welds. This is necessary because of space limitations. It is not known what effect such a weld has on the compressive load carrying capacity of an angle. The standards and specification examined allow an unbalanced weld for an angle. The justification for using such a weld is based on research conducted on angles in tension. For these members, it was concluded that an unbalanced weld does not affect the tensile load carrying capacity of the angle. Research results for angles with different weld patterns subjected to compressive loads are not available in the literature. Eighteen tests were conducted on angle compression members with various weld patterns. It was determined that an unbalanced weld is detrimental to the load carrying capacity of an intermediate length angle but is beneficial for a slender angle. Key words: angles, column (structural), compressive resistance, effective length, standards, welds.

Experimental evaluation of the compressive resistance of non-stress-relieved solid round steel columns

2008 ◽  
Vol 35 (11) ◽  
pp. 1221-1238
Author(s):  
K. Sennah ◽  
M. Saliba ◽  
M. Al-Hashimy ◽  
J. Wahba
Keyword(s):  
Research Council ◽  
Current Practice ◽  
Experimental Investigations ◽  
Test Program ◽  
Steel Columns ◽  
Economical Design ◽  
Communication Towers ◽  
Compressive Resistance ◽  
Supporting Structures ◽  
Resistance Equation

Solid round steel columns are commonly used as legs and also as diagonal and horizontal members of communication towers. The Canadian standard Antennas, towers, and antenna supporting structures, CSA S37–01, specifies empirical expressions for the compressive resistance of solid round columns based on the Structural Stability Research Council (SSRC) column curves for non solid round columns as well as the results from experimental investigations on solid rounds that have been carried out since 1965. As such, it was felt necessary to conduct an experimental study on non-stress-relieved steel solid round columns to refine the available design equations for such columns. This paper provides a summary of a recent test program on the compressive resistance of non-stress-relieved steel solid rounds. Correlation between the results from these tests and the current practice for the design of solid rounds is investigated. The paper concludes with a proposed compressive resistance equation for economical design of such columns.

Correlations between Gun-Barrels Temperature Rising and Shooting Specifications

2015 ◽  
Vol 775 ◽  
pp. 115-118 ◽  
Author(s):  
Yong Hai Shan ◽  
Zheng Gang Nie ◽  
Shi Qi Shan ◽  
Li Dong Tan
Keyword(s):  
Temperature Field ◽  
Temperature Variation ◽  
Field Testing ◽  
Test Results ◽  
Experimental Basis ◽  
Dynamic Tests ◽  
Life Test ◽  
The Relationship ◽  
Temperature Dynamic

Gun barrels life closely related to the gun barrels temperature variation. On the basis of analyzing gun barrels temperature various characteristics and rules during machine-guns firing, according to gun barrels life factors and their impact on gun barrels life, test programs under different shooting combined conditions and gun barrels temperature field testing programs are designed. Through the gun barrels temperature dynamic tests and test results during shooting, analyze and put forward the relationship between gun barrels temperature rising and firing specification. Which provides the experimental basis for choice of machine-gun barrels life stresses and analysis of the life-ended rules.

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