The Current State-of-the-Art in the Field of Material Models of Concrete and other Cementitious Composites

2015 ◽  
Vol 729 ◽  
pp. 134-139 ◽  
Author(s):  
Filip Hokes
Keyword(s):  
Prestressed Concrete ◽  
State Of The Art ◽  
Constitutive Relations ◽  
Concrete Structures ◽  
Material Model ◽  
Short Review ◽  
Material Models ◽  
Current State ◽  
Short Summary ◽  
Tension And Compression

The topic of this paper is the short review of current state-of-the-art in the field of material models of concrete and its utilization for numerical analysis of concrete and prestressed concrete structures. The problem of compiling constitutive relations for numerical simulation of concrete structures is not yet closed. It is caused by different behavior of concrete in tension and compression. Due to formation and development of cracks it is necessary to describe material model of concrete in tension as precisely as possible. The paper aims to create a brief historical overview in this field and then aims to create a short summary of current approaches that were published in conference contributions and in journals during recent years.

scholarly journals Flexural Behavior of Post-Tensioned Concrete Beams with Multiple Internal Corroded Strands

2020 ◽  
Vol 10 (22) ◽  
pp. 7994
Author(s):  
Chi-Ho Jeon ◽  
Chang-Su Shim
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Safety Issue ◽  
Material Model ◽  
Flexural Behavior ◽  
Bending Test ◽  
Material Models ◽  
Strain Compatibility ◽  
Prestressed Concrete Beam

The corrosion of prestressing steel in prestressed concrete bridges is a critical safety issue. To evaluate the strength of a prestressed concrete beam with corroded strands, it is necessary to know the mechanical properties of the corroded strands in terms of their tensile strength and ductility. In this study, material models were suggested using tensile tests of corroded strands which had been taken from existing bridges. Five prestressed concrete beams with multiple internal corroded strands of different corrosion levels and locations were fabricated and tested using the three-point bending test. The beams with corroded strands near the support did not show meaningful flexural behavior changes, while the beams with corrosion in the mid-span showed significant strength reduction. In order to suggest the appropriate evaluation of the flexural strength of a prestressed concrete beam with corroded strands, material models of the corroded strands were divided into two model categories: a bi-linear material model and a brittle material model. Strength evaluations of the corroded prestressed concrete beams according to fps approximation and strain-compatibility using OpenSEES were conducted. Results suggested the use of the strain compatibility method only when the section loss was greater than 5%.

scholarly journals Identification of thermal material parameters for thermo-mechanically coupled material models

Meccanica ◽  
2021 ◽  
Vol 56 (2) ◽  
pp. 393-416
Author(s):  
L. Rose ◽  
A. Menzel
Keyword(s):  
Evolution Equations ◽  
Constitutive Relations ◽  
Material Model ◽  
Basic Material ◽  
Dissipated Energy ◽  
Model Formulation ◽  
Material Models ◽  
Material Parameters ◽  
Simple Tension ◽  
The Impact

AbstractThe possibility of accurately identifying thermal material parameters on the basis of a simple tension test is presented, using a parameter identification framework for thermo-mechanically coupled material models on the basis of full field displacement and temperature field measurements. Main objective is to show the impact of the material model formulation on the results of such an identification with respect to accuracy and uniqueness of the result. To do so, and as a proof of concept, the data of two different experiments is used. One experiment including cooling of the specimen, due to ambient temperature, and one without specimen cooling. The main constitutive relations of two basic material models are summarised (associated and non-associated plasticity), whereas both models are extended so as to introduce an additional material parameter for the thermodynamically consistent scaling of dissipated energy. The chosen models are subjected to two parameter identifications each, using the data of either experiment and focusing on the determination of thermal material parameters. The influence of the predicted dissipated energy of the models on the identification process is investigated showing that a specific material model formulation must be chosen carefully. The material model with associated evolution equations used within this work does neither allow a unique identification result, nor is any of the solutions for the underlying material parameters close to literature values. In contrast to that, a stable, that is locally unique, re-identification of the literature values is possible for the boundary problem at hand if the model with non-associated evolution equation is used and if cooling is included in the experimental data.

scholarly journals Carbapenems: A Short Review about their Current Status

2021 ◽  
Vol 04 (01) ◽  
Author(s):  
Syeda Warda Zahra ◽  
Keyword(s):  
Cost Effectiveness ◽  
State Of The Art ◽  
Short Review ◽  
Current Status ◽  
Clinical Use ◽  
Beta Lactams ◽  
Beta Lactamases ◽  
Current State ◽  
The Cost

In this review, we summarize the current “state of the art” of carbapenem antibiotics and their role in our antimicrobial armamentarium. Among the beta-lactams currently available, carbapenems are unique because they are relatively resistant to hydrolysis by most beta-lactamases. Herein, we described the cost effectiveness, safety, and advantages of carbapenems as compared to other antibiotics. We also highlight important features of the carbapenems that are presently in clinical use: imipenem-cilastatin, meropenem, ertapenem, doripenem, panipenem-betamipron, and biapenem. In closing, we emphasize some major challenges related to oral formulatuion of carbapenems and different strategies to overcome these challenges.

scholarly journals Virtual Reality Support for Dental Treatment Premedication

2021 ◽  
Vol 10 (1) ◽  
pp. 102-106
Author(s):  
Tomasz ('Tomi') Kupka
Keyword(s):  
Virtual Reality ◽  
Literature Search ◽  
Dental Treatment ◽  
State Of The Art ◽  
Short Review ◽  
Medical Application ◽  
Minimal Invasive ◽  
Current State ◽  
Subsequent Literature

The objective is to short review the current state of the art of virtual reality medical application in term of minimal invasive dentistry. An outline of the most important aspects of virtual reality has been created, and a subsequent literature search for articles related was conducted. The current state of the art of virtual reality includes a variety of applications, among others premedication, analgesics, anaesthetics plays an important role in informatics medicine. There is a growing consensus regarding the need to develop knowledge and possible introduce virtual reality as a non-pharmacological support for dental treatment.

Behavioral Genetics: Concepts for Research and Practice in Language Development and Disorders

1995 ◽  
Vol 38 (5) ◽  
pp. 1126-1142 ◽  
Author(s):  
Jeffrey W. Gilger
Keyword(s):  
Language Development ◽  
Behavioral Genetics ◽  
State Of The Art ◽  
Genetic Research ◽  
Great Promise ◽  
Behavioral Genetic ◽  
Fine Grained ◽  
Future Goals ◽  
Current State ◽  
Research Designs

This paper is an introduction to behavioral genetics for researchers and practioners in language development and disorders. The specific aims are to illustrate some essential concepts and to show how behavioral genetic research can be applied to the language sciences. Past genetic research on language-related traits has tended to focus on simple etiology (i.e., the heritability or familiality of language skills). The current state of the art, however, suggests that great promise lies in addressing more complex questions through behavioral genetic paradigms. In terms of future goals it is suggested that: (a) more behavioral genetic work of all types should be done—including replications and expansions of preliminary studies already in print; (b) work should focus on fine-grained, theory-based phenotypes with research designs that can address complex questions in language development; and (c) work in this area should utilize a variety of samples and methods (e.g., twin and family samples, heritability and segregation analyses, linkage and association tests, etc.).

Schizophrenia Research: Current State of the Art

1976 ◽  
Vol 21 (7) ◽  
pp. 497-498
Author(s):  
STANLEY GRAND
Keyword(s):  
State Of The Art ◽  
Current State
Sign in / Sign up

Export Citation Format

Share Document