Evaluation of collapse mechanism of telecommunication tower

This paper presents evaluation of a 67.12m high telecommunication tower with the objectives of applying the Finite Element Method (FEM) in modelling it, analysing it under Nigerian wind loads from five different wind zones (Zone 1, Zone 2, Zone 3 Zone 4 and Zone 5 with basic wind speeds as 42m/s, 45.8m/s, 50m/s, 55m/s and 56m/s respectively). The collapse mechanism of the tower was predicted using the Mechanism Method. The tower was modelled and wind load was calculated on it and analysis shows that there is mechanism for the tower to collapse under dynamic wind loads as plastic hinges are developed at the joints and along bracing members. The most severe wind load was used in the plastic analysis conducted and it shows that when the plastic hinges developed at the lower section of the tower, the three mechanisms are more critical compared to when it develops at other sections of the tower. Also, using such load as the collapse load, when the plastic hinges developed at any section of the tower, combine mechanism is more critical and hence the tower is likely to collapse due to failure of both leg members and bracing members. Key words: Collapse, Mast, Steel Structure, Analysis

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Determining internal forces in modular building elements under action wind load

MATEC Web of Conferences ◽

10.1051/matecconf/201819602010 ◽

2018 ◽

Vol 196 ◽

pp. 02010

Author(s):

Viacheslav Shirokov ◽

Alexey Soloviev ◽

Tatiana Gordeeva

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Cross Section ◽

Dynamic Characteristics ◽

Wind Load ◽

Wind Loads ◽

Bending Moments ◽

The Finite Element Method ◽

Calculation Results ◽

Internal Forces

The research paper focuses on internal forces determination in the elements of modular buildings under wind load. It provides a methodology for determining dynamic characteristics of a building and for calculating wind loads. This method is based on the following assumptions: coupling of the modules elements is rigid; coupling of block-modules with foundations is hinged-fixed; connection of blocks to each other is hinged in angular points; the floor disk in its plane is not deformed. On the basis of these assumptions the authors derived approximate and refined equations for determining forces in modules elements under static and pulsation components of wind load. The equation of bending moments determination in the pillar bearing cross-section is obtained by approximation of the graph of moments variation, calculated for the spectrum of the ratio of the pillar stiffness and the floor beam in the range from 1/64 to 64. The paper further introduces the calculation results of forces based on the proposed methodology and on the finite element method. The calculations were done while taking different values of wind load and different number of storeys in a building (from 1 to 4 floors). The obtained results are similar, the error does not exceed 5%.

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Determining the Magnitude of Wind Loads on Structures in Kenya according to the Eurocodes

10.14293/s2199-1006.1.sor-.ppbrj1u.v3 ◽

2021 ◽

Author(s):

Muthomi Munyua

Keyword(s):

Wind Speed ◽

Structural Design ◽

Wind Load ◽

Wind Data ◽

Wind Loads ◽

Wind Loading ◽

Design Code ◽

Wind Speeds ◽

The Uk

This paper provides guidance on the use of existing wind data in Kenya with the Eurocodes despite the absence of the local national annexes. The determination of wind loads in the structural design of buildings according to the Eurocode Standard KS EN 1991-1-4:2005 in Kenya is challenging because of the lack of the Kenya National Annex. The design code commonly used in Kenya is CP3-Chapter V-2:1972 that uses the three-second gust duration. This gust duration results in higher magnitudes of wind loads that end up making the structures unnecessarily robust and uneconomical. Using the Eurocodes has the promise of achieving more economical designs because it uses the 10-minute gust duration. The 10-minute gust duration results in typically lower magnitudes of wind loads than the three-second gust duration for the same wind speed. Kenya adopted the Eurocodes in September 2012 but has not yet developed its national annexes opting instead to use the UK National Annexes. The UK National Annexes are applicable to Kenya in some scenarios but not in others such as wind loading. The lack of the Kenya National Annexes has led to difficulties in the adoption of the Eurocodes. This paper outlines a procedure in which the existing wind data given in three-second gusts could be converted to 10-minute wind speeds. Once converted, the method described in the UK National Annex could then be followed selectively to determine the wind load on a structure. Lastly, the paper recommends that wind data collected from 1977 to 2021 by the Kenya Meteorological Department be incorporated to the development of the wind map for the Kenya National Annex to KS EN 1991-1-4:2005

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FEA Based Wind Loads Analysis for the Main Steel Structure of Bucket Wheel Stacker-Reclaimer

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.721.414 ◽

2013 ◽

Vol 721 ◽

pp. 414-419

Author(s):

Peng Shang ◽

Xiao Guang Zhang ◽

Bo Xu ◽

Yong Cong Li ◽

Yu Ming Guan

Keyword(s):

Mechanical Behavior ◽

Steel Structure ◽

Maximum Load ◽

Work Conditions ◽

Wind Load ◽

Working Environment ◽

Wind Loads ◽

Safety And Reliability ◽

Loads Analysis ◽

Static Mechanical

Bucket wheel stacker-reclaimer is widely used in the field of material engineering machinery. Because of its working environment is very bad, it has higher requirements on its safety and reliability. Wind load calculations are necessary to ensure of the Static mechanical behavior. This paper mainly studied the main steel structure in a condition of no-load and maximum load work conditions and add the effects of the wind whose speed is about 20 m/s, At last all the stresses and strains were calculated based on FEA method.

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Elasto-Plastic Analysis of Uniform Grillages Under Lateral Load

Journal of Ship Research ◽

10.5957/jsr.1969.13.2.103 ◽

1969 ◽

Vol 13 (02) ◽

pp. 103-110

Author(s):

Thein Wah

Keyword(s):

Finite Difference ◽

Lateral Load ◽

Torsional Stiffness ◽

Collapse Mechanism ◽

Plastic Hinges ◽

Elastic Plastic ◽

Initial Loading ◽

Plastic Analysis ◽

The Matrix

A method is presented for analyzing elastic-plastic grillages under arbitrary loads by finite difference calculus. The torsional stiffness of the beams is neglected. The introduction of two discontinuity functions representing the rotation at the plastic hinges permits a complete description of the structure from initial loading until collapse. The development of a collapse mechanism is signified by the vanishing of the determinant of the matrix of the equations determining the amount of rotation at the plastic hinges.

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Determining the Magnitude of Wind Loads on Structures in Kenya according to the Eurocodes

10.14293/s2199-1006.1.sor-.ppbrj1u.v2 ◽

2021 ◽

Author(s):

Muthomi Munyua

Keyword(s):

Wind Speed ◽

Structural Design ◽

Wind Load ◽

Wind Data ◽

Wind Loads ◽

Wind Loading ◽

Code Of Practice ◽

Wind Speeds ◽

The Uk

This study provided guidance on the use of existing wind data in Kenya with the Eurocodes despite the absence of the local national annexes. The determination of wind loads in the structural design of buildings according to the Eurocode Standard KS EN 1991-1-4:2005 had several challenges. The code of practice commonly used in Kenya was CP3-Chapter V-2:1972 that used the three-second gust duration. This gust duration resulted in higher magnitudes of wind loads that ended up making the structures unnecessarily robust and uneconomical. Using the Eurocodes had the promise of achieving more economical designs because it used the 10-minute gust duration. The 10-minute gust duration resulted in typically lower magnitudes of wind loads than the three-second gust duration for the same wind speed. Kenya adopted the Eurocodes in September 2012 but had not yet developed its national annexes opting instead to use the UK National Annexes. The UK National Annexes were applicable to Kenya in some scenarios but not in others such as wind loading. The lack of the Kenya National Annexes led to difficulties in the adoption of the Eurocodes. This paper outlined a procedure in which the existing wind data given in three-second gusts could be converted to 10-minute wind speeds. Once converted, the method described in the UK National Annex could then be followed selectively to determine the wind load on a structure. Lastly, the paper recommended that wind data collected from 1977 to 2021 by the Kenya Meteorological Department be incorporated to the development of the wind map for the Kenya National Annex to KS EN 1991-1-4:2005.

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Researches on the Shear Deformation of Joints Domain of Beam-to-Column Connection of Light Steel Structure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.256-259.1004 ◽

2012 ◽

Vol 256-259 ◽

pp. 1004-1007

Author(s):

Xi Bing Hu ◽

Jian Hua Lu

Keyword(s):

Finite Element Method ◽

Shear Deformation ◽

Design Method ◽

Steel Structure ◽

Structure Calculation ◽

The Finite Element Method ◽

Mechanics Performance ◽

Current Design ◽

Internal Forces ◽

Complex Parts

The joint domain of beam-to-column connection is very complex parts under loading, which plays an important role in transferring internal forces in light steel structure, such as moment, shear, axial force and so on. Considering the influence of its shear deformation in the structure calculation can help us to reflect the actual mechanics performance and evaluate precisely practical bearing capacity of the structure. According to the actual characteristics of beam-to-column connection, the author established some models of its joint domain, and used the finite element method to analyze and calculate shear deformation of these models. Meanwhile, the author researched the influence of the changes of various parameters to its shear deformation, and provided beneficial suggestions for revising the current design method of light steel structure finally.

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Solar Concentrating Systems Using Small Mirror Arrays

Journal of Solar Energy Engineering ◽

10.1115/1.4000332 ◽

2009 ◽

Vol 132 (1) ◽

Cited By ~ 14

Author(s):

Joachim Göttsche ◽

Bernhard Hoffschmidt ◽

Stefan Schmitz ◽

Markus Sauerborn ◽

Reiner Buck ◽

...

Keyword(s):

Power Plants ◽

Raw Materials ◽

Large Fraction ◽

Steel Structure ◽

Steel Structures ◽

Cost Effective ◽

Wind Loads ◽

Drive Systems ◽

Mirror Area ◽

The Cost

The cost of solar tower power plants is dominated by the heliostat field making up roughly 50% of investment costs. Classical heliostat design is dominated by mirrors brought into position by steel structures and drives that guarantee high accuracies under wind loads and thermal stress situations. A large fraction of costs is caused by the stiffness requirements of the steel structure, typically resulting in ∼20 kg/m2 steel per mirror area. The typical cost figure of heliostats (figure mentioned by Solucar at Solar Paces Conference, Seville, 2006) is currently in the area of 150 €/m2 caused by the increasing price of the necessary raw materials. An interesting option to reduce costs lies in a heliostat design where all moving parts are protected from wind loads. In this way, drives and mechanical layout may be kept less robust, thereby reducing material input and costs. In order to keep the heliostat at an appropriate size, small mirrors (around 10×10 cm2) have to be used, which are placed in a box with a transparent cover. Innovative drive systems are developed in order to obtain a cost-effective design. A 0.5×0.5 m2 demonstration unit will be constructed. Tests of the unit are carried out with a high-precision artificial sun unit that imitates the sun’s path with an accuracy of less than 0.5 mrad and creates a beam of parallel light with a divergence of less than 4 mrad.

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Analysis of Wind Field Fan Based on Performance Enhancement Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.986-987.235 ◽

2014 ◽

Vol 986-987 ◽

pp. 235-238

Author(s):

Xiao Long Tan ◽

Jia Zhou ◽

Wen Bin Wang

Keyword(s):

Wind Speed ◽

Wind Turbines ◽

Performance Enhancement ◽

Aerodynamic Performance ◽

Wind Load ◽

Wind Speeds ◽

Enhancement Method ◽

Changes Over Time ◽

Load Simulation ◽

Single Constant

For the simulation of wind turbine, the wind speed is extremely important parameters and indicators to measure the output power of the unit is the wind load. Therefore, in the airflow dynamics and simulation of wind loads before establishing an accurate wind speed model is crucial. At present, the application for wind turbines COMSOL fan, fan blades and wind load simulation field, the extremely important wind speed model is not perfect, most of the research is confined to a single constant wind speed, wind speed virtually ignored the magnitude and direction of change, on changes over time and space at the same time is one of the few studies of wind, so find a way to accurately describe the range of wind speeds, and can be combined well with COMSOL method can greatly improve the aerodynamic performance of wind turbines the overall level of .

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