scholarly journals An Overview of Fatigue Testing Systems for Metals under Uniaxial and Multiaxial Random Loadings

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 447
Author(s):  
Julian M. E. Marques ◽  
Denis Benasciutti ◽  
Adam Niesłony ◽  
Janko Slavič
Keyword(s):  
Fatigue Testing ◽  
Local State ◽  
Specimen Geometry ◽  
Present Review ◽  
General Criterion ◽  
Classification Criterion ◽  
Test Type ◽  
State Of Stress ◽  
The Relationship

This paper presents an overview of fatigue testing systems in high-cycle regime for metals subjected to uniaxial and multiaxial random loadings. The different testing systems are critically discussed, highlighting advantages and possible limitations. By identifying relevant features, the testing systems are classified in terms of type of machine (servo-hydraulic or shaker tables), specimen geometry and applied constraints, number of load or acceleration inputs needed to perform the test, type of loading acting on the specimen and resulting state of stress. Specimens with plate, cylindrical and more elaborated geometry are also considered as a further classification criterion. This review also discusses the relationship between the applied input and the resulting local state of stress in the specimen. Since a general criterion to classify fatigue testing systems for random loadings seems not to exist, the present review—by emphasizing analogies and differences among various layouts—may provide the reader with a guideline to classify future equipment.

Private and Public Law

2020 ◽  
pp. 574-592
Author(s):  
Thomas W. Merrill
Keyword(s):  
Law And Economics ◽  
Public Law ◽  
Private Law ◽  
General Criterion ◽  
The Public ◽  
Private Ordering ◽  
Public Rights ◽  
Private And Public ◽  
The Relationship ◽  
Derivatives Of

This chapter explores the relationship between private and public law. In civil law countries, the public-private distinction serves as an organizing principle of the entire legal system. In common law jurisdictions, the distinction is at best an implicit design principle and is used primarily as an informal device for categorizing different fields of law. Even if not explicitly recognized as an organizing principle, however, it is plausible that private and public law perform distinct functions. Private law supplies the tools that make private ordering possible—the discretionary decisions that individuals make in structuring their lives. Public law is concerned with providing public goods—broadly defined—that cannot be adequately supplied by private ordering. In the twentieth and twenty-first centuries, various schools of thought derived from utilitarianism have assimilated both private and public rights to the same general criterion of aggregate welfare analysis. This has left judges with no clear conception of the distinction between private and public law. Another problematic feature of modern legal thought is a curious inversion in which scholars who focus on fields of private law have turned increasingly to law and economics, one of the derivatives of utilitarianism, whereas scholars who concern themselves with public law are increasingly drawn to new versions of natural rights thinking, in the form of universal human rights.

scholarly journals Power and Persuasion: Processes by Which Perceived Power Can Influence Evaluative Judgments

2017 ◽  
Vol 21 (3) ◽  
pp. 223-241 ◽  
Author(s):  
Pablo Briñol ◽  
Richard E. Petty ◽  
Geoffrey R. O. Durso ◽  
Derek D. Rucker
Keyword(s):  
The Self ◽  
Present Review ◽  
Psychological Processes ◽  
Short Term ◽  
Evaluative Judgments ◽  
Long Term Consequences ◽  
The Relationship ◽  
Structured Approach ◽  
Perceived Power

The present review focuses on how power—as a perception regarding the self, the source of the message, or the message itself—affects persuasion. Contemporary findings suggest that perceived power can increase or decrease persuasion depending on the circumstances and thus might result in both short-term and long-term consequences for behavior. Given that perceptions of power can produce different, and even opposite, effects on persuasion, it might seem that any relationship is possible and thus prediction is elusive or impossible. In contrast, the present review provides a unified perspective to understand and organize the psychological literature on the relationship between perceived power and persuasion. To accomplish this objective, present review identifies distinct mechanisms by which perceptions of power can influence persuasion and discusses when these mechanisms are likely to operate. In doing so, this article provides a structured approach for studying power and persuasion via antecedents, consequences, underlying psychological processes, and moderators. Finally, the article also discusses how power can affect evaluative judgments more broadly.

Microstructural Evolution and Stress Relaxation in Sputtered Tungsten Films

1993 ◽  
Vol 318 ◽  
Author(s):  
F. M. Ross ◽  
R. R. Kola ◽  
R. Hull ◽  
J. C. Bean
Keyword(s):  
Electron Microscope ◽  
Stress Relaxation ◽  
Microstructural Evolution ◽  
Transmission Electron Microscope ◽  
Specimen Geometry ◽  
Β Phase ◽  
Transmission Electron ◽  
The Relationship

ABSTRACTWe have investigated the relationship between microstructure and stress in very thin sputtered W films. We discuss features of the microstructure, in particular the presence of voids in compressively stressed films, in terms of the evolution of the structure from a metastable β-phase. By developing a novel specimen geometry for the transmission electron microscope (TEM), we present dynamic observations of the β-W→α-W transformation.

Fracture Toughness Estimation for Pipeline Girth Welds

2002 ◽  
Author(s):  
Henryk G. Pisarski ◽  
Colin M. Wignall
Keyword(s):  
Fracture Toughness ◽  
Weld Metal ◽  
Specimen Geometry ◽  
Single Edge ◽  
Single Edge Notch ◽  
Edge Notch ◽  
Loading Modes ◽  
Girth Welds ◽  
The Relationship ◽  
Single Edge Notch Bend

The relationship between fracture toughness estimated using standard single edge notch bend (SENB), single edge notch tension (SENT) test specimens and fracture toughness associated with a circumferential flaw in a pipe girth weld is explored in terms of constraint using the Q parameter. It is shown that in the elastic-plastic regime, use of standard deeply notched SENB specimens provides a conservative assessment of fracture toughness, for both weld metal and HAZ, because of the high constraint associated with this specimen geometry. Use of specimen geometries and loading modes associated with lower constraint (e.g. SENT and shallowed notched SENB specimens), allow for improved estimates of fracture toughness to be made that are appropriate for the assessment of circumferential flaws in pipe girth welds. Recommendations are given on the specimen designs and notch orientations to be employed when evaluating weld metal and HAZ fracture toughness.

scholarly journals Preparation of Samples used in Fatigue Testing of Aircraft Materials

2015 ◽  
Vol 2015 (7) ◽  
pp. 66-68
Author(s):  
Wojciech Manaj ◽  
Wojciech Wronicz ◽  
Andrzej Michałowski
Keyword(s):  
Residual Stress ◽  
Sample Preparation ◽  
Fatigue Testing ◽  
Mechanical Tests ◽  
Random Errors ◽  
Residual Surface Stress ◽  
State Of Stress ◽  
Surface Finishes ◽  
New Type ◽  
Destructive Methods

Abstract The application of a new type of alloy requires the evaluation of its properties, which is typically achieved with destructive methods. For this purpose, among others, static and fatigue mechanical tests are performed. Tests are performed on standardized samples in a way which reflects the level of stress occurring in real elements. These tests should limit random errors associated with sample preparation. For this reason the proper preparation of samples is crucial, not only in terms of their geometric dimensions but also in terms of the residual stress level. A sample preparation process was developed, involving checking samples’ surface for cracks, scratches, roughness, and the state of stress. The measurements are performed with nondestructive methods so as not to affect the proceeding research. In this study, the residual stress and features of a mechanically prepared surface were characterized. The specimens were subjected to various surface finishes mainly, lathe turning and grinding surface conditions. The effects of residual surface stress (measured by XRD) were studied after machining and polishing.

The Political Theory Implicit in Social Casework Theory

1953 ◽  
Vol 47 (4) ◽  
pp. 1076-1091 ◽  
Author(s):  
Alan Keith-Lucas
Keyword(s):  
United States ◽  
Political Theory ◽  
The United States ◽  
Local State ◽  
The Political ◽  
Government Function ◽  
The Past ◽  
National Governments ◽  
Relationship Of ◽  
The Relationship

The political theory implicit in social casework theory can be defined, for purposes of this discussion, as the theory of the relationship between man and society on which professional social casework is consciously predicated, or that theory of the relationship which is logically implied by social casework practice. This theory is not often consciously articulated and we must look for it, therefore, in those presuppositions underlying casework theory which are frequently accepted uncritically, if not wholly unconsciously. This practice obviously cannot be carried on without basic (although perhaps not entirely conscious) presuppositions about what man is like and consequently about what society can or ought to do for him.The presuppositions underlying social casework theory, although important in any context, have acquired a new significance to the extent that social casework has increasingly become a government function. During the past twenty years literally millions of people in the United States have been brought into a new relationship with officials of their local, state, and national governments—namely, the relationship of client and social caseworker.

scholarly journals The Dynamic and Fragile Nature of Eyewitness Memory Formation: Considering Stress and Attention

2021 ◽  
Vol 12 ◽  
Author(s):  
Alia N. Wulff ◽  
Ayanna K. Thomas
Keyword(s):  
Visual Field ◽  
Acute Stress ◽  
Inattentional Blindness ◽  
Memory Formation ◽  
Present Review ◽  
Future Research ◽  
Attentional Processes ◽  
Witness Memory ◽  
The Impact ◽  
The Relationship

Eyewitnesses are often susceptible to recollection failures and memory distortions. These failures and distortions are influenced by several factors. The present review will discuss two such important factors, attention failures and stress. We argue that acute stress, often experienced by eyewitnesses and victims of crimes, directly influences attentional processes, which likely has downstream consequences for memory. Attentional failures may result in individuals missing something unusual or important in a complex visual field. Amongst eyewitnesses, this can lead to individuals missing details, even unusual or important central details, regarding the crime. Surprisingly, few studies have investigated attentional failures in eyewitness scenarios, and none have investigated the relationship between stress, attention, and witness memory. This review will discuss the impact of attentional failures, mainly those resulting from inattentional blindness, in applied contexts in order to bridge to eyewitness scenarios. In addition, we will integrate the applied literature on attentional failures with literature that examines the influences of arousal and stress on attention. We will conclude by presenting how future research may tease apart the independent contributions of arousal and stress on attentional failures and successes and how this research may inform understanding of eyewitness reliability.

scholarly journals Mechanical Stresses Induced by Compression in Castings of the Load-carrying Grate

2016 ◽  
Vol 16 (2) ◽  
pp. 51-54
Author(s):  
J. Słowik ◽  
A. Drotlew ◽  
B. Piekarski
Keyword(s):  
Heat Treatment ◽  
Stress Distribution ◽  
Stress Level ◽  
Stress Transfer ◽  
State Of Stress ◽  
Structure Changes ◽  
Load Carrying ◽  
The Relationship ◽  
Forced Movement

Abstract The main aim of this study was to examine the compression-induced state of stress arising in castings of the guide grates during operation in pusher-type furnaces for heat treatment. The effect of grate compression is caused by its forced movement in the furnace. The introduction of flexible segments to the grate structure changes in a significant way the stress distribution, mainly by decreasing its value, and consequently considerably extends the lifetime of the grates. The stress distribution was examined in the grates with flexible segments arranged crosswise (normal to the direction of the grate compression) and lengthwise (following the direction of force). A regression equation was derived to describe the relationship between the stress level in a row of ribs in the grate and the number of flexible segments of a lengthwise orientation placed in this row. It was found that, regardless of the distribution of the flexible segments in a row, the stress values were similar in all the ribs included in this row, and in a given row of the ribs/flexible segments a similar state of stress prevailed, irrespective of the position of this row in the whole structure of the grate and of the number of the ribs/flexible segments introduced therein. Parts of the grate responsible for the stress transfer were indicated and also parts which play the role of an element bonding the structure.

scholarly journals A Revision of the Relationship between Gambling Disorder, Attention Deficit Hyperactivity Disorder and Parkinson´s Disease

2017 ◽  
Vol 13 (22) ◽  
pp. 89-107
Author(s):  
Gabriel C. Quintero-Garzola
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Attention Deficit Disorder ◽  
Gambling Disorder ◽  
Present Review ◽  
Gambling Problem ◽  
Hyperactivity Disorder ◽  
Search Terms ◽  
Number Of Publications ◽  
The Relationship

Purpose: For the present review, publications in the field of gambling disorder that deal with its relationships with others, mainly attention deficit hyperactivity disorder (ADHD) and Parkinson’s disease (PD) were consulted.Methods: The current revision includes a total of 63 references published between 1987 and 2017. It included human stud­ies and revisions regarding the comorbidity of gambling disorder with ADHD or PD. The search terms included: gambling disorder, gambling disorder comorbidity, gambling disorder and adhd, gambling disor­der and pd, gambling disorder and impulsivity. The present review fo­cused on the link among gambling disorder and ADHD or PD, because there were a large number of publications related to these disorders. For organization purpose the current work was split into two main parts: 1) Revision of previous scientific reviews about gambling dis­order, and 2) Overview and conclusions of experimental work about gambling disorder.Conclusions: The principal conclusions of the cur­rent review are: 1) subjects with a gambling disorder have a higher in­cidence of ADHD(and also of attention deficit disorder [ADD]), 2) the presence of ADHD in subjects that suffer of gambling disorder implies more challenges for the health care system, and 3) PD treatments that increase the agonism of dopamine type of receptor are related to an elevated probability for developing a gambling problem or an impulse control disorder.

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