scholarly journals Numerical determination of the onset of local necking using time dependent evaluation method and dynamic material parameters

2016 ◽  
Vol 734 ◽  
pp. 032015 ◽  
Author(s):  
D Jocham ◽  
W Volk
Keyword(s):  
Evaluation Method ◽  
Time Dependent ◽  
Numerical Determination ◽  
Local Necking ◽  
Material Parameters

Numerical Determination of Fatigue Threshold from CTOD

2016 ◽  
Vol 258 ◽  
pp. 290-293
Author(s):  
Daniel Camas ◽  
Pedro Loureiro ◽  
Pedro Prates ◽  
Fernando Antunes
Keyword(s):  
Plastic Deformation ◽  
Parametric Study ◽  
Numerical Approach ◽  
Fatigue Threshold ◽  
Numerical Determination ◽  
Experimental Procedure ◽  
Material Parameters

The experimental procedure to obtain valid and comparable values of ΔKth is laborious and time consuming. The objective of this work is to determine ΔKth using a numerical approach. The CTOD is plotted versus load, and the fatigue threshold corresponds to the onset of plastic deformation. A parametric study was developed in order to understand the effect of material parameters on ΔKth.

Methods of risk assessment in forecasting the consequences of accidents at pipeline transport facilities

2020 ◽  
Vol 10 (6) ◽  
pp. 663-673
Author(s):  
Vladislav N. Slepnev ◽  
◽  
Alexander F. Maksimenko ◽  
Elena V. Glebova ◽  
Alla Т. Volokhina ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Evaluation Method ◽  
Assessment Procedure ◽  
Expert Evaluation ◽  
Main Pipeline ◽  
Pipeline Transport ◽  
Forecasting Accuracy ◽  
Distribution Of Resources ◽  
Expert Evaluation Method

The choice of risk assessment procedure is one of the essential stages of efficient structuring of processes on prevention, localization and elimination of the consequences of accidents at main pipeline transport facilities. The authors analyzed themed publications and regulatory documents, governing procedures of risk assessment and forecasting of the consequences of possible accidents, and defined main problems in this area. Procedure for the risk assessment of accidents at main pipeline facilities was developed, the basis of which is the expert evaluation method. The procedure includes the determination of the main criteria for the assessment the probability of accident initiation and development and the evaluation of the severity of its consequences, an expert evaluation of criteria significance, their classification, and creation of a rating for hazardous pipeline sections. The application of the procedure application allows to specify the list of facilities that require high priority forecasting of accidents consequences, thus to optimize the distribution of resources and the overall increase of efficiency in planning while defining forces and special technical devices, necessary for containment and rectification of emergencies. Expert evaluation method application allows considering the specifics of certain enterprises, their technical and technological peculiarities, thereby increasing forecasting accuracy.

Experimental and Numerical Determination of Micropropulsion Device Efficiencies at Low Reynolds Numbers

2004 ◽  
Author(s):  
Andrew D. Ketsdever ◽  
Michael T. Clabough ◽  
Sergey F. Gimelshein ◽  
Alina Alexeenko
Keyword(s):  
Reynolds Numbers ◽  
Numerical Determination ◽  
Low Reynolds Numbers ◽  
Low Reynolds

scholarly journals A simulation-based approach to evaluate objective material parameters from concrete rheometer measurements

2019 ◽  
Vol 29 (1) ◽  
pp. 130-140 ◽  
Author(s):  
Florian Gerland ◽  
Alexander Wetzel ◽  
Thomas Schomberg ◽  
Olaf Wünsch ◽  
Bernhard Middendorf
Keyword(s):  
Yield Stress ◽  
High Performance ◽  
Evaluation Method ◽  
High Performance Concrete ◽  
Direct Determination ◽  
Plastic Viscosity ◽  
Flow Properties ◽  
Fresh Sample ◽  
Material Parameters ◽  
Simulation Based

Abstract Modern concretes such as ultra-high performance concrete (UHPC) show excellent strength properties combined with favorable flow properties. However, the flow properties depend strongly on process parameters during production (temperature, humidity etc.), but also change sensitively even with slight variations in the mixture. In order to ensure desired processing of the fluidlike material and consistent process quality, the flow properties of the concrete must be evaluated quantitatively and objectively. The usual evaluation of measurements from concrete rheometers, for example of the ball probe system type, does not allow the direct determination of the objective material parameters yield stress and plastic viscosity of the sample. We developed a simulation-based method for the evaluation of rheometric measurements of fine grained high performance concretes like self-compacting concrete (SCC) and UHPC. The method is based on a dimensional analysis for ball measuring systems. Through numerical parameter studies we were able to describe the identified relationship between measuring quantities and material parameters quantitatively for two devices of this type. The evaluation method is based on the Bingham model. With this method it is possible to measure both the yield stress and the plastic viscosity of the fresh sample simultaneously. Device independence of the evaluation process is proven and an application to fiber-reinforced UHPC is presented.

scholarly journals Determination of time-dependent strengths of salt pillars based on strain energy principle

2019 ◽  
Vol 29 (2) ◽  
pp. 273-279 ◽  
Author(s):  
Prapasiri Junthong ◽  
Supattra Khamrat ◽  
Suratwadee Sartkaew ◽  
Kittitep Fuenkajorn
Keyword(s):  
Strain Energy ◽  
Time Dependent ◽  
Energy Principle
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