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Modeling of Worsening
Abstract
This paper aims to add impetus to understanding of worsening phenomena and prevention of their consequences. The introductory notes outline the uncertainty, the empirical character and the subjective meaning of the term "worsening". The underlying hypothesis takes up the idea of general cause and effect relations in order to reveal the cause and effect interaction concept of worsening. The concept of worsening is analytically modeled as an accumulation of effects in permanent interaction with causes. The mathematical formulation of the worsening concept is applied to examples of common engineering problems of material plasticity, fatigue and corrosion.
... The article at the beginning presents the mechanical load redistribution model along the crack to its end on a lattice of microstructural particles in crystalline materials following the concept of crack growth ki- netics [13] . The study reveals the empirical concept of Cause-and- Effect-Interaction (CEI)14151617 for mathematical formulation of Fatigue crack growth and Endurance Interaction (FEI) induced by overstressing due to load redistribution under cyclic loads. The mechanical interaction model of load redistribution replaces in the article the commonly used numerical methods for fitting of crack growth and crack growth rate [18]. ...
... In engineering of materials FCG is generally viewed as a Causeand-Effect (CE) relation between progressing number N of cyclic loads (the cause C) and increasing crack size a(N) (the effect E). The hypothesis of the next study is that mechanical load redistribution and overstressing processes in which accumulation of degradation of material properties depends simultaneously on failure propagation and on residual strength can be described by the Cause-and-Effect-Interaction (CEI) concept14151617. Succinctly, the overstressing rate due to load redistribution after each subsequent load cycle N accelerates the forthcoming crack growth on expense of continuous diminution of finite fatigue endurance induced by the foregoing crack growth in interactive manner. ...
This article presents how to link together the results of fatigue crack growth tests, analytic fracture mechanics and experimental methods of fatigue lifetime predictions. The study at the beginning investigates the effect of mechanical load redistribution among failed and intact micro-structural bonds along fatigue crack growth to final crack at vulnerable locations in materials and structures under cyclic loads. The microstructural load redistribution model is analytically formulated as a mechanical interaction between fatigue crack growth and fatigue endurance on the macroscopic level. The article in continuation investigates how to link the parameters of fatigue crack growth in fracture mechanics to parameters of fatigue life directly from the work done on crack growth determined by testing. The article at the end illustrates the application of the analytic procedure for fatigue lifetime prediction that combines fracture mechanics and the load redistribution model for determination of S- N curve parameters important in structural analysis and design. In this research the fatigue life time parameters are derived from a single fatigue crack growth experiment instead from normally required sets of fatigue tests for different loading conditions.
... It is of some particular practical importance to mention that the characteristic function ϕ X (u) has been established as a member of the extremely significant class of selfdecomposable characteristic functions [11]. More precisely, such an establishment substantially extents the practical and theoretical applicability of the random variable X in a very wide variety of scientific disciplines [8,9,12]. ...
... The random variable J is said a random contraction of the random variable H via the random variable V (Hashorva et al., 2010). It is of particular interest to mention that the contribution in practical situations of random contractions consists of their very useful applications in income distribution analysis (Krishnaji, 1970), cindynics (Kervern, 1994), continuous discounting (De Schepper et al., 2002), reliability theory (Bazovsky, 2004), inventory control (Waters, 2007), operations research (Taha, 2007), proactive risk management (Artikis and Artikis, 2010), engineering (Schwarzlander, 2011), systemics (Ziha, 2012), and informatics (Artikis et al., 2015). The present paper concentrates on the implementation of the following four purposes. ...
... The random variable J is said a random contraction of the random variable H via the random variable V (Hashorva et al., 2010). It is of particular interest to mention that the contribution in practical situations of random contractions consists of their very useful applications in income distribution analysis (Krishnaji, 1970), cindynics (Kervern, 1994), continuous discounting (De Schepper et al., 2002), reliability theory (Bazovsky, 2004), inventory control (Waters, 2007), operations research (Taha, 2007), proactive risk management (Artikis and Artikis, 2010), engineering (Schwarzlander, 2011), systemics (Ziha, 2012), and informatics (Artikis et al., 2015). The present paper concentrates on the implementation of the following four purposes. ...
The formulation of stochastic models suitable for proactive treatment of global information risks incorporates structural concepts of global information risk governance and fundamental results of probability theory. The theoretical and practical contribution of the first chapter of this work is comprised of the above mentioned structural concepts and fundamental results. As a result, the contribution of formulating stochastic models aimed at improving the discipline of global risk governance is easily accepted as particularly valuable in theory and practice.KeywordsGlobal riskGlobal risk governanceInformation scienceProbability theoryStochastic model
Abstract: The article firstly investigates a discrete numerical model of finite interaction between successive microstructural bond failures and remaining intact internal bonds in materials. Secondly, it reveals the general linear finite continuous cause and effect interaction concept. The interaction model is examined numerically, experimentally and analytically on an illustrative case of a parallel system of bonds. The general concept is applied to the macroscopic stress-strain interaction model of material plasticity. Examples of metallic materials are elaborated on reported theoretical and experimental strain data.
The paper on the first place summarizes the fatigue yield approach as a cause-effect interaction between fatigue damage progression and fatigue endurance. Secondly it investigates the fatigue strength worsening on experimental S-N data and the load variability effects in shipbuilding. Next it applies the Classification Society's rule-based procedure for fatigue analysis of ship’ s structure that uses a simplified fatigue strength assessment method. The example elaborates fatigue yield effect on the seagoing operation of a double hull 47400 tdw tanker. At the end the paper recommends the procedure for assessment of ship lifetime shortening due to the fatigue yielding under constant and variable amplitude block loadings.
The paper describes the fatigue strength assessment of oil tanker hull girder taking into account degradation of ship hull due to the corrosion. Hull girder degradation is represented as time-varying stress increase caused by time-varying loss of midship section modulus. Nonlinear function representing hull girder section modulus loss is based on recently published corrosion measurements on large number of single-hull oil tankers. Fatigue damage accumulation is calculated for different corrosion severity by integrating time-varying instantaneous fatigue damage. Proposed method represents an improvement of the fatigue assessment procedure compared to Common Structural Rules, as the “rule” method is based on simplified assumption that corrosion wastage is constant in whole lifetime of the vessel. The paper also considers the fatigue yielding due to possible worsening of fatigue resistance due to alternating load cases and load variability in addition to the lifetime shortening due to corrosion.
This paper proposes a time-variant probabilistic corrosion model derived from a database with 157 thickness measurement records of 140 tankers. Incorporating the corrosion model in a time-dependent reliability method and referring to a required limit of safety level, a reliability-based inspection planning is proposed for ship-type floating production, storage, and offloading units (FPSOs) based on corrosion renewal criteria that account simultaneously for thickness reduction, hull girder ultimate strength, stiffened panel buckling strength, and plate ultimate strength.
The paper on the first place summarizes the fatigue yield approach as a cause-effect interaction between fatigue damage progression and fatigue endurance. Secondly it investigates the fatigue strength worsening on experimental S-N data and the load variability effects in shipbuilding. Next it applies the Classification Society's rule-based procedure for fatigue analysis of ship's structure that uses a simplified fatigue strength assessment method. The example elaborates fatigue yield effect on the seagoing operation of a double hull 47400 tdw tanker. At the end the paper recommends the procedure for assessment of ship lifetime shortening due to the fatigue yielding under constant and variable amplitude block loadings.
The paper describes the fatigue strength assessment of oil tanker hull girder taking into account degradation of ship hull due to the corrosion. Hull girder degradation is represented as time-varying stress increase caused by time-varying loss of midship section modulus. Nonlinear function representing hull girder section modulus loss is based on recently published corrosion measurements on large number of single-hull oil tankers. Fatigue damage accumulation is calculated for different corrosion severities by integrating time-varying instantaneous fatigue damage. Proposed method represents an improvement of the fatigue assessment procedure compared to Common Structural Rules, as the "rule" method is based on simplified assumption that corrosion wastage is constant in whole lifetime of the vessel. The paper also considers the fatigue yielding due to possible worsening of fatigue resistance due to alternating load cases and load variability in addition to the lifetime shortening due to corrosion.
Knitted textiles and apparel represent approximately one third of the global textile market. This book provides an updated reference to Knitting technology, with specific focus on the developments in knitted fabric production and textile applications. The first set of chapters begin with a brief review of the fundamental principles of knitting, including the types and suitability of yarns for knitting as well as the properties achieved through knitted fabrics. The second part of the book examines the major advances in knitting, such as intelligent yarn delivery systems in weft knitting, knitted fabric composites and advances in circular knitting. The concluding section of the book presents a selection of case studies where advanced knitted products are used. Topics range from knitted structures for moisture management to weft knitted structures for sound absorption. With its distinguished editor and array of international contributors, Advances in knitting technology is an important text for designers, engineers and technicians involved in the manufacture and use of knitted textiles and garments. It will also be relevant for academics and students.
The paper starts with a brief review of fatigue damage progression under block loadings and then investigates in more details a fatigue yield model. The study identifies the fatigue yield as a cause-effect interaction of damage and endurance rather than as a physical process in the traditional fatigue engineering. The experimental data under variable and constant stress amplitude loadings reported up to date were used for the evaluation of the fatigue yield approach. Analytical, numerical and recursive procedures for fatigue yield assessments were carried out and illustrated by examples.
Written by one of the preeminent researchers in the field, this book provides a comprehensive exposition of modern analysis of causation. It shows how causality has grown from a nebulous concept into a mathematical theory with significant applications in the fields of statistics, artificial intelligence, economics, philosophy, cognitive science, and the health and social sciences. Judea Pearl presents and unifies the probabilistic, manipulative, counterfactual, and structural approaches to causation and devises simple mathematical tools for studying the relationships between causal connections and statistical associations. The book will open the way for including causal analysis in the standard curricula of statistics, artificial intelligence, business, epidemiology, social sciences, and economics. Students in these fields will find natural models, simple inferential procedures, and precise mathematical definitions of causal concepts that traditional texts have evaded or made unduly complicated. The first edition of Causality has led to a paradigmatic change in the way that causality is treated in statistics, philosophy, computer science, social science, and economics. Cited in more than 5,000 scientific publications, it continues to liberate scientists from the traditional molds of statistical thinking. In this revised edition, Judea Pearl elucidates thorny issues, answers readers’ questions, and offers a panoramic view of recent advances in this field of research. Causality will be of interests to students and professionals in a wide variety of fields. Anyone who wishes to elucidate meaningful relationships from data, predict effects of actions and policies, assess explanations of reported events, or form theories of causal understanding and causal speech will find this book stimulating and invaluable.
This book develops a manipulationist theory of causation and explanation: causal and explanatory relationships are relationships that are potentially exploitable for purposes of manipulation and control. The resulting theory is a species of counterfactual theory that (I claim) avoids the difficulties and counterexamples that have infected alternative accounts of causation and explanation, from the Deductive-Nomological model onwards. One of the key concepts in this theory is the notion of an intervention, which is an idealization of the notion of an experimental manipulation that is stripped of its anthropocentric elements. This notion is used to provide a characterization of causal relationships that is non-reductive but also not viciously circular. Relationships that correctly tell us how the value of one variable Y would change under interventions on a second variable Y are invariant. The notion of an invariant relationship is more helpful than the notion of a law of nature (the notion on which philosophers have traditionally relied) in understanding how explanation and causal attribution work in the special sciences.
Fatigue damage increases with applied load cycles in a cumulative manner. Cumulative fatigue damage analysis plays a key role in life prediction of components and structures subjected to field load histories. Since the introduction of damage accumulation concept by Palmgren about 70 years ago and ‘linear damage rule’ by Miner about 50 years ago, the treatment of cumulative fatigue damage has received increasingly more attention. As a result, many damage models have been developed. Even though early theories on cumulative fatigue damage have been reviewed by several researchers, no comprehensive report has appeared recently to review the considerable efforts made since the late 1970s. This article provides a comprehensive review of cumulative fatigue damage theories for metals and their alloys, emphasizing the approaches developed between the early 1970s to the early 1990s. These theories are grouped into six categories: linear damage rules; nonlinear damage curve and two-stage linearization approaches; life curve modification methods; approaches based on crack growth concepts; continuum damage mechanics models; and energy-based theories.
It is the author belief that cybernetics should be considered not merely as a program to be carried out in the future, but as an existing science. In this book the author's intention is to express and to exemplify his ideas on cybernetics and to display some of his personal philosophical reflections
Atlas of Stress-strain Curves
- Y Tamarin
Y. Tamarin, Atlas of Stress-strain Curves, ASM
International, 2002.
- K Ziha
- Fatigue Yield
K. Ziha, Fatigue Yield, Int J of Fatigue 31, 1211-1214,
2009.
- L H Van
- Vlack
L.H. Van Vlack, Elements of Materials Science and
Engineering, Addison-Wesley, 1985.
Description of stress-strain curves by three parameters, Technical Note No. 902, National Advisory Committee For Aeronautics
- W Ramberg
- W R Osgood
W. Ramberg, W. R. Osgood, Description of stress-strain
curves by three parameters, Technical Note No. 902,
National Advisory Committee For Aeronautics, Washington
DC, 1943.
- L H Van Vlack
L.H. Van Vlack, Elements of Materials Science and
Engineering, Addison-Wesley, 1985.
Rules & Guidance, Rules for Classification and Construction
- Germanischer Lloyd
Germanischer Lloyd, Rules & Guidance, Rules for
Classification and Construction, Ship Technology. Part 1.
Seagoing Ships, Chapter 1 -Hull Structures, Section 20 -Fatigue Strength, 2008.
NACE Corrosion Engineers Reference Book, NACE International (National Association of Corros
- R S Treseder
- R Baboian
R.S. Treseder, R. Baboian (Ed.), NACE Corrosion
Engineers Reference Book, NACE International (National
Association of Corros; 3rd Revised edition edition, 2002.