scholarly journals General response observed in cyclically loaded cohesive soils

2016 ◽  
Vol 26 (1) ◽  
pp. 21 ◽  
Author(s):  
Andres Nieto Leal ◽  
Victor N. Kaliakin
Keyword(s):  
Cyclic Loading ◽  
Experimental Work ◽  
Constitutive Models ◽  
Cohesive Soils ◽  
Specific Test ◽  
Substantial Body ◽  
Test Conditions ◽  
Key Characteristics ◽  
Different Types ◽  
General Response

<p>The response of cohesive soils subjected to cyclic loading is affected by different factors; the most important are soil type, stress or consolidation history, and specific test conditions. To better understand the behavior of cohesive soils subjected to cyclic loading, beginning in early 1960’s, a rather substantial body of experimental work has been performed. This has involved different types of soils, tested at different values of overconsolidation ratio, and subjected to different cyclic loading histories. This paper compiles the most important findings of the aforementioned experimental work on cohesive soils. It summarizes the general behavioral trends observed for cyclically loaded cohesive soils. Besides, several key characteristics of cyclically loaded cohesive soils that any rational mathematical simulation must account for have been identified, thus offering the general trends that should be taken into account in the development of new constitutive models used in predicting the response of such soils.</p>

Characteristics of Physicians Referred for a Competence Assessment: A Comparison of State Medical Board and Hospital Referred Physicians

2010 ◽  
Vol 96 (3) ◽  
pp. 8-15 ◽  
Author(s):  
Elizabeth S. Grace ◽  
Elizabeth J. Korinek ◽  
Zung V. Tran
Keyword(s):  
Clinical Competence ◽  
Competence Assessment ◽  
Average Performance ◽  
Medical Board ◽  
Key Characteristics ◽  
Different Types ◽  
Specialty Board ◽  
And Performance ◽  
State Medical Boards ◽  
State Medical Board

ABSTRACT This study compares key characteristics and performance of physicians referred to a clinical competence assessment and education program by state medical boards (boards) and hospitals. Physicians referred by boards (400) and by hospitals (102) completed a CPEP clinical competence assessment between July 2002 and June 2010. Key characteristics, self-reported specialty, and average performance rating for each group are reported and compared. Results show that, compared with hospital-referred physicians, board-referred physicians were more likely to be male (75.5% versus 88.3%), older (average age 54.1 versus 50.3 years), and less likely to be currently specialty board certified (80.4% versus 61.8%). On a scale of 1 (best) to 4 (worst), average performance was 2.62 for board referrals and 2.36 for hospital referrals. There were no significant differences between board and hospital referrals in the percentage of physicians who graduated from U.S. and Canadian medical schools. The most common specialties referred differed for boards and hospitals. Conclusion: Characteristics of physicians referred to a clinical competence program by boards and hospitals differ in important respects. The authors consider the potential reasons for these differences and whether boards and hospitals are dealing with different subsets of physicians with different types of performance problems. Further study is warranted.

THEORY OF LAW AND PHILOSOPHY OF LAW AS THEORETICAL DISCOURSES: SPECIFICS AND RELATIONSHIP

2020 ◽  
pp. 9-17
Author(s):  
Вадим Леонидович Афанасьевский
Keyword(s):  
Scientific Knowledge ◽  
Scientific Theory ◽  
Theoretical Concept ◽  
Philosophy Of Law ◽  
The West ◽  
Scientific Creativity ◽  
Key Characteristics ◽  
Different Types ◽  
Theory Of Law ◽  
The Relationship

В статье анализируется проблема взаимоотношений философии права и научной теории права. Рассматриваемая проблема стала особенно актуальной в российском образовательном пространстве в связи с введением после длительного перерыва в государственный образовательный стандарт магистратуры по юриспруденции учебной дисциплины «Философия права». Автор статьи в качестве базисного принимает тезис, согласно которому философия права, являясь сферой философской мысли, и теория права как область научного социогуманитарного знания представляют собой разные типы теоретического дискурса. Исходя из этого, в статье выстраивается теоретическая концепция, согласно которой задачей философии права как философского типа мышления является конструирование или экспликация онтологических, эпистемологических, аксиологических, феноменологических оснований для формирования и функционирования научных теоретико-правовых и историко-правовых построений. Для реализации поставленной в статье задачи подробно рассматриваются ключевые характеристики как теории философского типа, так и идеалов, норм и характеристик научного знания. Выявленное различие экстраполируется на взаимоотношение теории права как продукта научного творчества и философии права как конструкции, задающей базовые мировоззренческие смыслы. В качестве примера выработанных философией права и государства оснований научных теорий прогресса, государства, морали и права, автор приводит взгляды мыслителей западноевропейской философской классики: Т. Гоббса, Ж.-Ж. Руссо, И. Канта, Г.В.Ф. Гегеля. Именно их философские концепции предопределили образы теоретико- и историко-правовых учений XVIII, XIX, XX и даже начала XXI в. Таким образом, отношение философии права и теории права выстраивается по «вертикали»: от онтологического основания к возведению теоретико-правовых и историко-правовых научных построений. The article analyzes the problem of the relationship between the philosophy of law and the scientific theory of law. The problem under consideration has become especially urgent in the Russian educational space in connection with the introduction of the Philosophy of Law discipline master's degree in law after a long break. The author of the article takes as the basis the thesis that the philosophy of law, being the sphere of philosophical thought, and the theory of law as a field of scientific socio-humanitarian knowledge are different types of theoretical discourse. Based on this, the article builds a theoretical concept according to which the task of the philosophy of law as a philosophical type of thinking is the construction or explication of ontological, epistemological, axiological, phenomenological grounds for the formation and functioning of concrete scientific theoretical and legal and historical and legal constructions. To implement the task posed in the article, the key characteristics of both a theory of a philosophical type and ideals, norms and characteristics of scientific knowledge are examined in detail. The revealed difference is extrapolated to the relationship between the theory of law as a product of scientific creativity and the philosophy of law as a construction that sets basic philosophical meanings. As an example of the foundations of the scientific theories of progress, state, morality and law developed by the philosophy of law and the state, the author gives the views and thinkers of the West European philosophical classics T. Hobbes, J.-J. Russo, I. Kant, G.V.F. Hegel. It was their philosophical concepts that predetermined the images of theoretical and historical-legal doctrines of the XVIII, XIX, XX and even the beginning of the XXI centuries. Thus, the attitude of the philosophy of law and the theory of law is built along the «vertical»: from the ontological foundation to the construction of theoretical and historical and historical legal scientific constructions.

Fire spreading experiments on heterogeneous fuel beds. Applications of percolation theory

2000 ◽  
Vol 30 (8) ◽  
pp. 1318-1328 ◽  
Author(s):  
Jean Nahmias ◽  
Hervé Téphany ◽  
José Duarte ◽  
Sophie Letaconnoux
Keyword(s):  
Experimental Work ◽  
Percolation Theory ◽  
Dynamic Behaviour ◽  
Fire Spread ◽  
Directed Percolation ◽  
Final State ◽  
Critical Thresholds ◽  
Scale Models ◽  
Different Types ◽  
Fire Spreading

In the experimental work presented here, fire spread was studied through various laboratory and full-scale models containing different types of combustible and noncombustible materials. We have examined the dynamic behaviour of the flame front and the final state (after extinction) on randomly created heterogeneous zones, both with and without wind. The principal conclusion is that critical thresholds exist, for the ratio between combustible and noncombustible parts, at the transition between nonpropagation and propagation of the fire. This result is common to all types of spreading (with or without wind). The values of the critical thresholds in the nonwind-driven experiments are those of the percolation theory. The critical exponent, obtained for wind-driven experiments, is in accordance with current values suggested by the directed percolation approach.

Comparing the Seismic Performance of Beam-Column Joints with and without SFRC when Subjected to Cyclic Loading

2012 ◽  
Vol 626 ◽  
pp. 85-89 ◽  
Author(s):  
Kay Dora Abdul Ghani ◽  
Nor Hayati Hamid
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Experimental Work ◽  
Concrete Beam ◽  
Steel Fiber ◽  
Precast Concrete ◽  
Experimental Results ◽  
Column Joint ◽  
Initial Cracks

The experimental work on two full-scale precast concrete beam-column corner joints with corbels was carried out and their seismic performance was examined. The first specimen was constructed without steel fiber, while second specimen was constructed by mixed up steel fiber with concrete and placed it at the corbels area. The specimen were tested under reversible lateral cyclic loading up to ±1.5% drift. The experimental results showed that for the first specimen, the cracks start to occur at +0.5% drifts with spalling of concrete and major cracks were observed at corbel while for the second specimen, the initial cracks were observed at +0.75% with no damage at corbel. In this study, it can be concluded that precast beam-column joint without steel fiber has better ductility and stiffness than precast beam-column joint with steel fiber. However, precast beam-column joint with steel fiber has better energy dissipation and fewer cracks at corbel as compared to precast beam-column joint without steel fiber.

New Hybrid Methodology for the Development of MEMS Multivariable Sensors

2001 ◽  
Author(s):  
Emily J. Pryputniewicz ◽  
John P. Angelosanto ◽  
Gordon C. Brown ◽  
Cosme Furlong ◽  
Ryszard J. Pryputniewicz
Keyword(s):  
Process Control ◽  
Microelectromechanical Systems ◽  
Absolute Pressure ◽  
Single Chip ◽  
Specific Test ◽  
Mems Sensor ◽  
Test Conditions ◽  
Mems Technology ◽  
Functional Operation ◽  
Hybrid Methodology

Abstract Using recent advances in microelectromechanical systems (MEMS) technology, a new multivariable sensor was developed. This MEMS sensor, capable of measuring temperature, absolute pressure, and differential pressure on a single chip, is particularly suitable for applications in process control industry. However, functional operation of the sensor depends on validation of its performance under specific test conditions. We have developed a hybrid methodology, based on analysis and measurements, that allows such validation. In this paper, the MEMS multivariable sensor is described, the hybrid methodology is outlined, and its use is illustrated with representative results.

scholarly journals Numerical Modeling of Masonry-infilled RC Frame

2019 ◽  
Vol 13 (1) ◽  
pp. 135-148 ◽  
Author(s):  
Christiana A. Filippou ◽  
Nicholas C. Kyriakides ◽  
Christis Z. Chrysostomou
Keyword(s):  
Cyclic Loading ◽  
Numerical Model ◽  
Constitutive Models ◽  
Control Analysis ◽  
Rc Frame ◽  
Initial Stiffness ◽  
Element Analysis ◽  
Rc Frames ◽  
Rc Frame Structures ◽  
Infilled Rc Frames

Background: The behavior of masonry-infilled Reinforced Concrete (RC) frame structures during an earthquake, has attracted the attention of structural engineers since the 1950s. Experimental and numerical studies have been carried out to investigate the behavior of masonry-infilled RC frame under in-plane loading. Objective: This paper presents a numerical model of the behavior existing masonry-infilled RC frame that was studied experimentally at the University of Patra. The objective of the present study is to identify suitable numerical constitutive models for each component of the structural system in order to create a numerical tool to model the masonry infilled RC frames in-plane behavior by accounting the frame-infill separation. Methods: A 2D masonry-infilled RC frame was developed in DIANA Finite Element Analysis (FEA) software and an eigenvalue and nonlinear structural cyclic analyses were performed. It is a 2:3 scale three-story structure with non-seismic design and detailing, subjected to in-plane cyclic loading through displacement control analysis. Results: There is a good agreement between the numerical model and experimental results through a nonlinear cyclic analysis. It was found that the numerical model has the capability to predict the initial stiffness, the ultimate stiffness, the maximum shear-force capacity, cracking- patterns and the possible failure mode of masonry-infilled RC frame. Conclusion: Therefore, this model is a reliable model of the behavior of masonry-infilled RC frame under cyclic loading including the frame-infill separation (gap opening).

Developing an Implicit Creep Model From Open Literature Data

2021 ◽  
Author(s):  
William David Day
Keyword(s):  
Failure Time ◽  
Rupture Life ◽  
Creep Model ◽  
Full Data ◽  
Element Analysis ◽  
Specific Test ◽  
Projection Model ◽  
Data Set ◽  
Test Conditions ◽  
Creep Models

Abstract As pressure ratios and firing temperatures continue to rise, creep becomes of greater concern everywhere within a gas turbine engine. As a rule of thumb, just a 14°C increase in metal temperature can halve the expected rupture life of a part. In the past, companies might be satisfied with conservative creep estimates based on Larson-Miller-Parameter curves and 1D calculations. Now companies need functional implicit-creep models with finite element analysis for an ever-increasing number of materials. Obtaining adequate test data to create a good creep prediction model is an expensive and time-consuming proposition. Test costs depend on temperature, material, and location, but a single, 10,000hr, rupture test may reasonably be expected to cost &gt; $20,000. Other than large OEMs, small companies and individuals lack the resources to create creep models from their own data. This paper will lead the reader through the creation of a modified theta projection creep model of Haynes 282, a high-temperature, combustion alloy, using only literature data. First, literature data is collected and reviewed. Data consists of very few complete curves, estimated stresses for rupture and 1% strain, and discrete times to individual strains for individual tests. When adequate data exists, individual tests are fit to theta projection model curves. These “local” theta fits of different test conditions are used as input for the global model. Global fits of theta parameters, as a function of stress and temperature, are made from the full data set. As the global creep model is improved, correction factors introduced to account for true stress and strain effects. A statistical analysis is made of actual rupture time versus predicted onset of failure time, theta5=1. A time-based scatter factor is determined to evaluate temperature margin required to ensure reliability. After the creep model was completed, Haynes International, the material inventor, provided specific test conditions (stress and temperature) of 5 tests that had already been run. Creep predictions were generated for these test conditions, before viewing the actual results. The creep model predicted strain curves matched actual tests very well, both in shape and time to rupture. Continued refinement is possible as more data is acquired.

A Comparative Study of the Response of Double Shearing and Hypoplastic Models

2002 ◽  
Author(s):  
Huaning Zhu ◽  
Morteza M. Mehrabadi ◽  
Mehrdad Massoudi
Keyword(s):  
Cyclic Loading ◽  
Mechanical Response ◽  
Constitutive Relations ◽  
Constitutive Models ◽  
Shear Loading ◽  
Biaxial Compression ◽  
Finite Element Program ◽  
Cyclic Shear ◽  
Hypoplastic Model ◽  
Element Program

The principal objective of this paper is to compare the mechanical response of a double shearing model with that of a hypoplastic model under biaxial compression and under cyclic shear loading. As the origins and nature of these two models are completely different, it is interesting to compare the predictions of these two models. The constitutive relations of the double shearing and the hypoplastic models are implemented in the finite element program ABACUS/Explicit. It is found that the hypoplastic and the double shearing constitutive models both show strong capability in capturing the essential behavior of granular materials. In particular, under the condition of non-cyclic loading, the stress ratio and void ratio predictions of the double shearing and the hypoplastic models are relatively close, while under the condition of cyclic loading, the predictions of these models are quite different. It is important to note that in the double shearing model employed in this comparison the shear rates on the two slip systems are assumed to be equal. Hence, the conclusions derived in this comparison pertain only to this particular double shearing model. Similarly, the hypoplasticity model considered here is that proposed by Wu, et al. [30] and the conclusions reached here pertain only to this particular hypoplasticity model.

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