Home > Search Results: 999C1a:GA106/02/0745
Search:
Search Tips :: Advanced Search
Search collections:
Sort by: Display results: Output format:
National Repository of Grey Literature 3 records found  Search took 0.01 seconds. 
The Weibull Stress Parameters Calibration upon the Toughness Scaling Model between Cracks Having Different Constraint
 Kozák, Vladislav ; Vlček, Libor
An extensive investigation has been carried out on the sensitivity parameters determination describing the fracture behaviour of body with crack with respect to the character change of true stress-strain curve with dominant region of Lueders deformation.Consequently,its convenient substitution has been tested.This paper presents the consideration on the change judgement of J-integral and constraint as the base parameters of two-parameters fracture mechanics.The Weibull stress model for cleavage fracture of cast steel requires calibration of two micromechanics parameters (m,ó u).Weibull stress seems to be a parameter for prediction of cleavage failure of cracked bodies and the study is focused on the assessment of the effects of constraint loss on cleavage fracture toughness (Jc).To quantify the effects of constraint variation on the cleavage fracture toughness the form of the toughness-scaling model based on the Weibull stress ó w is investigated.Local material parameters have been calculated arising from Beremin approach and calibration is based on various approaches.Methods are based on weakest link assumption and incremental fracture probability,which depends not only on the maximum principal stress,but also on the equivalent plastic strain.The fracture resistance has been assessed using data from static tests of there point bend specimens.
Detailed record
Bainitic steel for frogs of rail switches - development and properties
 Dlouhý, Ivo ; Zbořil, J. ; Holzmann, Miloslav
Mechanical properties and fracture behaviour of newly developed cast bainitic steel Lo8CrNiMo, predetermined for the frogs of rail switches, has been investigated. Properties of rail steel of the type UIC 900A has been followed for comparison. According to characteristics obtained steel Lo8CrNiMo displays much better fracture resistance when compared to standard rail steel. Dynamic fracture toughness is the same as static fracture toughness. This finding has great practical importance with respect to dynamic loading to frog.
Detailed record
Parameters identification for GTN model and their verification on the CrMo4 steel
 Kozák, Vladislav ; Vlček, Libor
Exact measurement of deformation and fracture material characteristics in laboratory enables determination of micromechanical parameters for GTN model. The attention is paid on the influence of initial value of J- integral and the slope of R-curve on the local stress triaxiality. Good agreement between numerical simulation and experimentally measured R-curve was found.
Detailed record

Interested in being notified about new results for this query?
Subscribe to the RSS feed.
Digital Repository :: Search :: Submit :: Personalize :: Help
Powered by Invenio v1.1.2
Maintained by admin.invenio@techlib.cz
This site is also available in the following languages:
Česky  English