scholarly journals FUNDAMENTALS OF CREEP, TESTING METHODS AND DEVELOPMENT OF TEST RIG FOR THE FULL-SCALE CROSSARM: A REVIEW

2019 ◽  
Vol 81 (4) ◽  
Author(s):  
M. R. M. Asyraf ◽  
M. R. Ishak ◽  
M. R. Razman ◽  
M. Chandrasekar
Keyword(s):  
Mechanical Performance ◽  
Primary Objective ◽  
Full Scale ◽  
Creep Testing ◽  
Galvanized Steel ◽  
Test Rig ◽  
Creep Theory ◽  
Lack Of Information ◽  
Glass Fibre Reinforced Polymer ◽  
Tropical Weather

Most of transmission line (TL) towers are designed and fabricated in the form of lattice using galvanized steel. The crossarm of the TL is made of Neobalanocarpus or Chengal wood. Recently, it has been reported by an electrical corporation situated in Malaysia that mechanical performance of the wooden crossarm declined below their service life of 40 years due to the extreme tropical weather in Malaysia. At present, composite crossarm made of glass fibre reinforced polymer composite were introduced as substitute in the 132 kV TL tower. However, the research findings lack of information on creep life estimation for the full-scale crossarm. Hence, a new test rig has to be developed to cater the testing operation using the uniaxial tension creep test. The primary objective of this review is to provide an overview of the creep theory and the existing creep testing methodology.

scholarly journals Mechanical performance of full-scale prototype quadrupole magnets for the SSC

1993 ◽  
Vol 3 (1) ◽  
pp. 699-704
Author(s):  
J.M. Cortella ◽  
A. Devred ◽  
A. Wandesforde
Keyword(s):  
Mechanical Performance ◽  
Full Scale

scholarly journals Cerebrovascular diseases mortality in the elderly in the state of São Paulo

2021 ◽  
Author(s):  
Isaac Rêgo Purificação ◽  
Allêh Kauãn Santos Nogueira ◽  
Matheus Araújo de Souza ◽  
Camila de Almeida Costa Alencar ◽  
Sancha Mohana Brito Goes Rios
Keyword(s):  
Age Groups ◽  
The Elderly ◽  
Cross Sectional Study ◽  
Cerebrovascular Diseases ◽  
Sao Paulo ◽  
Primary Objective ◽  
The State ◽  
São Paulo ◽  
Cross Sectional ◽  
Lack Of Information

Background: Cerebrovascular disease (CVD) is the world 2nd death cause and the main cause of disability. Nevertheless, there is a lack of information regarding the mortality profile for this etiology in the last decade. Objective and Methods: Using prospectively collected data available in TabNet (DataSUS) platform, a descriptive and cross-sectional study was conducted. The primary objective is to access the demographic information most associated with DCV mortality in individuals older than 50 years-old, in São Paulo (SP), from 2010 to 2019. Results: The highest mortality in the state of SP was in 2019 (16,945 deaths), according to the growing trend; in the 2010-2019 period, the annual mean by city of deaths (± standard deviation [SD]) was 14,885 (± 1,341). During these years, the number of deaths was higher in the municipality of São Paulo (57,013; 31%). The annual mean deaths (± SD) in the capital and in the interior cities were, respectively: 4,684 (± 269) and 31 (± 58). The age groups from 70 to 79 years and over 80 years were the most affected. Caucasian race represents 71% of deaths. Individuals with 1 to 3 years of school were more affected (38%). The ratio of male deaths to female deaths was 1.02. Conclusion: In the last decade, there was an increasing mortality by CVD among the elderly population, and the city of São Paulo leads the number of cases.

Modelling of Thermoacoustic Combustion Instabilities Phenomena: Application to an Experimental Rig for Testing Full Scale Burners

2014 ◽  
Author(s):  
Davide Laera ◽  
Giovanni Campa ◽  
Sergio M. Camporeale ◽  
Edoardo Bertolotto ◽  
Sergio Rizzo ◽  
...  
Keyword(s):  
Acoustic Analysis ◽  
Fem Analysis ◽  
Full Scale ◽  
Operating Conditions ◽  
System Modelling ◽  
Combustion Instabilities ◽  
Test Rig ◽  
Pressure Oscillations ◽  
Secondary Air ◽  
Actual Geometry

This paper concerns the acoustic analysis of self–sustained thermoacoustic pressure oscillations that occur in a test rig equipped with full scale lean premixed burner. The experimental work is conducted by Ansaldo Energia and CCA (Centro Combustione Ambiente) at the Ansaldo Caldaie facility in Gioia del Colle (Italy), in cooperation with Politecnico di Bari. The test rig is characterized by a longitudinal development with two acoustic volumes, plenum and combustion chamber, coupled by the burner. The length of both chambers can be varied with continuity in order to obtain instability at different frequencies. A previously developed three dimensional finite element code has been applied to carry out the linear stability analysis of the system, modelling the thermoacoustic combustion instabilities through the Helmholtz equation under the hypothesis of low Mach approximation. The heat release fluctuations are modelled according to the κ-τ approach. The burner, characterized by two conduits for primary and secondary air, is simulated by means of both a FEM analysis and a Burner Transfer Matrix (BTM) method in order to examine the influence of details of its actual geometry. Different operating conditions, in which self–sustained pressure oscillations have been observed, are examined. Frequencies and growth rates of unstable modes are identified, with good agreement with experimental data in terms of frequencies and acoustics pressure wave profiles.

scholarly journals Aeroelastic Stability Analysis of a Full-Scale Isolated Proprotor on the Tiltrotor Test Rig

2019 ◽  
Author(s):  
Sesi B. Kottapalli ◽  
Carl R. Russell ◽  
Cecil W. Acree ◽  
Thomas R. Norman
Keyword(s):  
Stability Analysis ◽  
Full Scale ◽  
Aeroelastic Stability ◽  
Test Rig

scholarly journals Microstructure and Mechanical Properties of Galvanized-45 Steel/AZ91D Bimetallic Material by Liquid-Solid Compound Casting

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1651 ◽  
Author(s):  
Jun Cheng ◽  
Jian-hua Zhao ◽  
Jin-yong Zhang ◽  
Yu Guo ◽  
Ke He ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Corrosion Current ◽  
Eutectic Structure ◽  
Galvanized Steel ◽  
X Ray Diffraction ◽  
Solid Compound ◽  
Metallurgical Bonding ◽  
Compound Casting ◽  
Bimetallic Material ◽  
Bimetallic Materials

A connection between hot-dip galvanized 45 steel and AZ91D was achieved by liquid-solid compound casting to achieve one material with a better mechanical performance and a light weight. The microstructure and properties of galvanized-steel/AZ91D bimetallic materials were investigated in this study. A scanning electron microscopy (SEM), an energy dispersive spectroscopy (EDS), and an X-ray diffraction (XRD) were applied to analyze the microstructure evolution and formation mechanism of the galvanized 45 steel/AZ91D interface zone which could be divided into three layers. Among three different layers, the layer close to AZ91D was composed of α-Mg and an eutectic structure (α-Mg + MgZn). The intermediate layer was comprised of an eutectic structure (α-Mg + MgZn), and the layer adjacent to 45 steel consisted of α-Mg and FeAl3. Furthermore, galvanized-45 steel/AZ91D bimetallic material had better shear strength than the bare-45 steel/AZ91D metallic material which can indicate that owing to the formation of metallurgical bonding, the adhesive strength of galvanized-steel and AZ91D was improved to 11.81 MPa. In addition, the fact that corrosion potential increased from −1.493 V to −1.143 V and corrosion current density changed from 3.015 × 10−5 A/cm2 to 1.34 × 10−7 A/cm2 implied that the corrosion resistance of galvanized-steel/AZ91D was much better than AZ91D.

Research on Microstructure and Wear Resistance of Double Glow Plasma Discharge Surface Titanizing on CrZrCu Alloy

2010 ◽  
Vol 154-155 ◽  
pp. 79-82
Author(s):  
Bo Lin He ◽  
Fang Tu ◽  
Jing Liu
Keyword(s):  
Wear Resistance ◽  
Spot Welding ◽  
Steel Sheet ◽  
Mechanical Performance ◽  
Layer Structure ◽  
Plasma Discharge ◽  
Experimental Results ◽  
Galvanized Steel ◽  
Glow Discharge Plasma ◽  
Glow Plasma

CrZrCu is extensively used in spot welding due to their high electrical, thermal and mechanical performance. But when CrZrCu electrode is used in spot welding of galvanized steel sheet, the abrasion, corrosion and oxidation shorten the electrode life rapidly. The electrode is not able to meet the needs of spot welding of galvanized steel sheet .In the paper, double glow plasma discharge surface titanizing was carried out on CrZrCu alloy. The processes of double glow plasma discharge titanizing, surface alloying layer structure were also analyzed elementary. The wear resistance property of glow discharge plasma titanizing layer was also researched. The experimental results indicated that in the plasma titanizing alloying layer, the diffusion of titanium element toward the interior of the CrZrCu alloy substrate forms the intermetallic compound named Cu4Ti, which is beneficial to the reinforcement of CrZrCu substrate. The experimental results confirmed that double glow plasma discharge titanizing could improve the wear resistance of CrZrCu alloy greatly. Under the external load of 300N and 500N, the wear resistance of double glow plasma discharge titanizing layer is7 times and 8.5 times than that of CrZrCu.

scholarly journals Flexural Behavior of a 30-Meter Full-Scale Simply Supported Prestressed Concrete Box Girder

2020 ◽  
Vol 10 (9) ◽  
pp. 3076 ◽  
Author(s):  
Jianqun Wang ◽  
Shenghua Tang ◽  
Hui Zheng ◽  
Cong Zhou ◽  
Mingqiao Zhu
Keyword(s):  
Prestressed Concrete ◽  
Mechanical Performance ◽  
Compressive Strain ◽  
Full Scale ◽  
Flexural Behavior ◽  
Destructive Testing ◽  
Scaled Model ◽  
Box Girder ◽  
Simply Supported ◽  
Prestressing Tendon

Compared with scaled-model testing, full-scale destructive testing is more reliable since the test has no size effect and can truly record the mechanical performance of the structure. However, due to the high cost, only very few full-scale destructive tests have been conducted on the flexural behavior of prestressed concrete (PC) box girders with girders removed from decommissioned bridges. Moreover, related destructive testing on the flexural behavior of a new precast box girder has been rarely reported. To investigate the flexural behavior and optimize the design, destructive testing of a 30-meter full-scale simply supported prestressed box girder was conducted at the construction site. It is illustrated that the failure mode of the tested girder was fracture of the prestressing tendon, and the corresponding maximum compressive strain in the top flange was only 1456 μ ε , which is far less than the ultimate compressive strain (3300 μ ε ). Therefore, the concrete in the top flange was not fully utilized. A nonlinear analysis procedure was performed using the finite strip method (FSM). The validity of the analysis was demonstrated by comparing the analytical results with those of the full-scale test in the field and a scaled model test in a laboratory. Using the developed numerical method, parametric analyses of the ratio of reinforcement were carried out. The prestressing tendon of the tested girder was increased from four strands to six strands in each duct. After the optimization of the prestressed reinforcement, the girder was ductile and the bearing capacity could be increased by 44.3%.

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