scholarly journals Post on the Issue of Safety of Steel Structures of Hot Dip Galvanized Structural Components

2012 ◽  
Vol 40 ◽  
pp. 241-246 ◽  
Author(s):  
V. Kuklik
Keyword(s):  
Steel Structures ◽  
Structural Components

Analysis on Critical CTOD of Long-Term Used Penstock

2017 ◽  
Vol 741 ◽  
pp. 57-62
Author(s):  
Fumito Kawamura ◽  
Masazumi Miura ◽  
Ryuichiro Ebara ◽  
Keiji Yanase
Keyword(s):  
Fracture Toughness ◽  
Structural Integrity ◽  
Steel Structures ◽  
Chemical Compositions ◽  
Structural Components ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Critical Crack ◽  
Crack Tip Opening

Many studies have been conducted to characterize the fracture toughness of structural steels and their welded joints. However, most studies focus on newly developed steels, and the number of studies on the fracture toughness of long-term used steels in structural components is rather limited. Furthermore, a lack of data on the fracture toughness causes difficulties in evaluating the structural integrity of existing steel structures. In this study, CTOD tests were performed to characterize the fracture toughness of penstock that has been in service for 50 years. By measuring the critical crack tip opening displacement in conjunction with analysis for chemical compositions, the characteristics of fracture toughness were investigated.

Study of ISO 19901-3 Building Code Correspondence Factor for Eurocode 3

2013 ◽  
Author(s):  
Nicolas Neumann
Keyword(s):  
Cross Sections ◽  
Steel Structures ◽  
Building Code ◽  
Structural Components ◽  
The North ◽  
A Value ◽  
Eurocode 3 ◽  
European Code ◽  
The North Sea ◽  
Design Resistance

For topside structures ISO 19901-3 rely on national or regional building codes to derive the resistance of structural components. It is, however, required that the design resistance(s) of the building code is matched to the design resistance(s) of ISO 19902 through the use of a building code correspondence factor Kc. Recently, Kc was proposed in the literature to be taken as 0.95 for the European code for steel structures, Eurocode 3 (EN 1993). The present study does not support this value. Instead a value of 0.86 is derived. This lower value is based on the investigation of a topside project in the North Sea, and intends to cover for the stricter requirements to component resistance in ISO 19902 compared to Eurocode 3 for plastic and compact cross-sections.

scholarly journals Probabilistic Risk-Based Performance Evaluation of Seismically Base-Isolated Steel Structures Subjected to Far-Field Earthquakes

Buildings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 128 ◽  
Author(s):  
Aryan Rezaei Rad ◽  
Mehdi Banazadeh
Keyword(s):  
Fragility Curves ◽  
Steel Structures ◽  
Superior Performance ◽  
Far Field ◽  
Structural Components ◽  
Moment Frames ◽  
Damage States ◽  
Nonlinear Dynamic Analyses ◽  
Rubber Bearings ◽  
Maximum Earthquake

The performance of base-isolated steel structures having special moment frames is assessed. The archetypes, which are designed per ASCE/SEI 7–2016, are simulated in the Finite Element (FE) computational platform, OpenSees. Adopting nonlinear dynamic analyses using far-field ground motions, the performance of Drift-Sensitive Structural Components (DS-SC), and Drift-/Acceleration-Sensitive Non-Structural Components (DS/AS NSC) at slight, moderate, extensive, and collapse damage states are investigated. The effects of structural height, effective transformed period (Teff), response modification coefficient (RI), and isolation type on the performance of 26 archetypes mounted on Lead Rubber Bearings (LRBs) and Triple Concave Friction Pendulums (TCFPs) are evaluated. Computing 50-year probability of exceedance using the fragility curves and seismic hazard curves of the site, increasing Teff reduces the role of RI in the structural performance; variations in the height, as well as RI, do not affect the risk of damages to the AS-NSC; the risk of collapse is not sensitive to the variations of Teff. The TCFP systems represent superior performance than LRB systems in lower intensities. For longer periods and taller structures, the isolation type has less effect on the performance of NSC. Finally, the archetypes have less than 1% risk of collapse in 50 years; nevertheless, high-rise structures with RI = 2.0 have more than 10% probability of collapse given the maximum earthquake.

Application of Equivalent CTOD Ratio to Fracture Assessment of Structural Components

2008 ◽  
Author(s):  
Satoshi Igi ◽  
Mitsuru Ohata ◽  
Fumiyoshi Minami
Keyword(s):  
Fracture Toughness ◽  
Large Scale ◽  
Steel Structures ◽  
Structural Components ◽  
Steel Component ◽  
Draft Standard ◽  
Application Procedure ◽  
Edge Surface ◽  
Fracture Assessment ◽  
Scale Test

Plastic constraint correction using the equivalent CTOD concept has been studied in the IST project. This project was carried out over a 3-year period with the foundation of METI in Japan, and the results were summarized in a draft standard, “Method of constraint loss correction of CTOD fracture toughness for fracture assessment of steel component.” Equivalent CTOD ratio β is proposed in terms of constraint loss correction between the fracture performance of steel structures and fracture toughness tests using the Weibull stress as the driving force of brittle fracture. This paper provides the application procedure of Equivalent CTOD ratio to the fracture assessment of structural components. Equivalent CTOD ratio was taken in the fracture assessment diagram, and discussed the applicability by comparison with large scale test result of structural component such as Edge Surface Crack Panel, Center Through-wall crack panel and so on.

Application of Equivalent CTOD Ratio to Fracture Assessment of Structural Components

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Satoshi Igi ◽  
Mitsuru Ohata ◽  
Fumiyoshi Minami
Keyword(s):  
Fracture Toughness ◽  
Large Scale ◽  
Steel Structures ◽  
Evaluation Procedure ◽  
Structural Components ◽  
Steel Component ◽  
Application Procedure ◽  
Edge Surface ◽  
Toughness Evaluation ◽  
Fracture Assessment

Plastic constraint correction using the equivalent CTOD concept has been studied in the International Standardization of Fracture Toughness Evaluation Procedure for Fracture Assessment of Steel Structures project. This project was carried out over a 3-year period with the foundation of the Japanese Ministry of Economy, Trade, and Industry, and the results were summarized in a draft standard “Method of constraint loss correction of CTOD fracture toughness for fracture assessment of steel component.” Equivalent CTOD ratio β is proposed in terms of the constraint loss correction between the fracture performance of steel structures and fracture toughness tests using the Weibull stress as the driving force of the brittle fracture. This paper provides the application procedure of equivalent CTOD ratio to the fracture assessment of structural components. Equivalent CTOD ratio was taken in the failure assessment diagram, and discussed the applicability by comparison with large scale test results of structural component such as edge surface crack panel, center through-wall crack panel, and other geometries.

scholarly journals Efficient modelling of flexible cable-pulley systems

2020 ◽  
Author(s):  
Markus Spiegelhauer ◽  
Berthold Schlecht
Keyword(s):  
Finite Element ◽  
Stiffness Matrix ◽  
Spatial Configuration ◽  
Steel Structures ◽  
Element Model ◽  
Finite Element Models ◽  
Structural Components ◽  
Cable System ◽  
Stiffness Matrices ◽  
Universal Procedure

AbstractThis article proposes a universal procedure for efficiently modelling the flexible behaviour of pre-stressed cables, guided by multiple pulleys. Such cable-pulley systems usually connect various structural components, which often feature additional flexibility. One concern in holistic system analyses is to correctly describe the elasticity of the entire assembly for one particular spatial configuration. This can be achieved in terms of a linear stiffness matrix that accounts for the kinematics of the assembly. In this article, parametric stiffness matrices for arbitrary cable-pulley arrangements are derived. A reduction scheme is used to facilitate the integration of the derived stiffness matrix into superordinate finite element models. The method is validated with a non-linear finite element model and applied to a complex hoisting cable system connecting multiple large steel structures.

Response and Failure of Internal Structural Subsystems Under Blast and Shock Loading

1994 ◽  
Vol 116 (4) ◽  
pp. 409-418
Author(s):  
D. W. Tennant ◽  
H. S. Levine
Keyword(s):  
Transient Analysis ◽  
Shock Loading ◽  
Failure Modes ◽  
Three Dimensional ◽  
Structural Response ◽  
Steel Structures ◽  
Structural Components ◽  
Nonlinear Transient ◽  
Potential Failure ◽  
Ground Shock

The objective of this paper is to evaluate the ability to accurately predict the motions, structural response, and failure modes of internal structural components subjected to high-intensity airblast and ground shock loading. The cases of interest involve a surface flush, buried reinforced concrete cylinder that is expected to experience negligible damage, within which are contained aluminum and steel structures that may or may not be shock-isolated at the internal attachment points. The structures and subsystems are modeled in detail using the FLEX three-dimensional nonlinear transient analysis code. The analyses were carried out using the soil island approach to represent the local airblast-induced, direct-induced, and crater-related ground shock from a simulated nuclear explosion. A test involving only local airblast effects with hard-mounted internal substructures was conducted. Comparisons of data from this test with calculations will be presented. Calculations will also be included that show potential failure mechanisms for the internal subsystems and their causes.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

Freeze-fracture cytochemistry: A goal set by Russell Steere in 1957

1993 ◽  
Vol 51 ◽  
pp. 60-61
Author(s):  
Nicholas J Severs
Keyword(s):  
Chemical Nature ◽  
Biological Systems ◽  
Freeze Fracture ◽  
Structural Components ◽  
Major Goal ◽  
Membrane Biology ◽  
Routine Application ◽  
The Future ◽  
Freeze Etching

In his pioneering demonstration of the potential of freeze-etching in biological systems, Russell Steere assessed the future promise and limitations of the technique with remarkable foresight. Item 2 in his list of inherent difficulties as they then stood stated “The chemical nature of the objects seen in the replica cannot be determined”. This defined a major goal for practitioners of freeze-fracture which, for more than a decade, seemed unattainable. It was not until the introduction of the label-fracture-etch technique in the early 1970s that the mould was broken, and not until the following decade that the full scope of modern freeze-fracture cytochemistry took shape. The culmination of these developments in the 1990s now equips the researcher with a set of effective techniques for routine application in cell and membrane biology.Freeze-fracture cytochemical techniques are all designed to provide information on the chemical nature of structural components revealed by freeze-fracture, but differ in how this is achieved, in precisely what type of information is obtained, and in which types of specimen can be studied.

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