Damage modeling of bituminous mixtures considering mixture microstructure, viscoelasticity, and cohesive zone fracture

2010 ◽  
Vol 37 (8) ◽  
pp. 1125-1136 ◽  
Author(s):  
Yong-Rak Kim ◽  
Francisco T.S. Aragão ◽  
David H. Allen ◽  
Dallas N. Little
Keyword(s):  
Finite Element Method ◽  
Cohesive Zone ◽  
Laboratory Testing ◽  
Model Material ◽  
Fracture Properties ◽  
Model Simulations ◽  
Bituminous Mixtures ◽  
Technical Issues ◽  
Complete Failure ◽  
Fracture Damage

This paper describes the development and application of a computational modeling approach incorporated with pertinent laboratory testing that can be used to predict fracture damage performance of bituminous paving mixtures. In the model, material viscoelasticity, mixture microstructure, and cohesive zone fracture properties are implemented within a finite element method, which is intended to simulate nonlinear-inelastic microscale fracture and its propagation to complete failure in bituminous mixtures. The model is applied to different materials, and the resulting model simulations are compared to experimental results for model validation. With some limitations and technical issues to be overcome in the future, the model presented herein clearly demonstrates several advancements based on its features accounting for material viscoelasticity, heterogeneity, and cohesive zone fracture. Potentially, the model can provide significant savings in time and costs and can also be used to improve currently available design analysis tools.

Investigating the Rolling Contact Fatigue in Rails Using Finite Element Method and Cohesive Zone Approach

2018 ◽  
Author(s):  
Mohamad Ghodrati ◽  
Mehdi Ahmadian ◽  
Reza Mirzaeifar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Grain Boundaries ◽  
Fatigue Damage ◽  
Cohesive Zone ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wheel Load ◽  
Element Method

A micromechanical-based 2D framework is presented to study the rolling contact fatigue (RCF) in rail steels using finite element method. In this framework, the contact patch of rail and wheel is studied by explicitly modeling the grains and grain boundaries, to investigate the potential origin of RCF at the microstructural level. The framework incorporates Voronoi tessellation algorithm to create the microstructure geometry of rail material, and uses cohesive zone approach to simulate the behavior of grain boundaries. To study the fatigue damage caused by cyclic moving of wheels on rail, Abaqus subroutines are employed to degrade the material by increasing the number of cycles, and Jiang-Sehitoglu fatigue damage law is employed as evolution law. By applying Hertzian moving cyclic load, instead of wheel load, the effect of traction ratio and temperature change on RCF initiation and growth are studied. By considering different traction ratios (0.0 to 0.5), it is shown that increasing traction ratio significantly increases the fatigue damage. Also by increasing traction ratio, crack initiation migrates from the rail subsurface to surface. The results also show that there are no significant changes in the growth of RCF at higher temperatures, but at lower temperatures there is a measurable increase in RCF growth. This finding correlates with anecdotal information available in the rail industry about the seasonality of RCF, in which some railroads report noticing more RCF damage during the colder months.

scholarly journals Physical Modeling of Cross Wedge Rolling Limitations

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 867 ◽  
Author(s):  
Łukasz Wójcik ◽  
Zbigniew Pater ◽  
Tomasz Bulzak ◽  
Janusz Tomczak
Keyword(s):  
Physical Modeling ◽  
Laboratory Testing ◽  
Physical Modelling ◽  
Rolling Process ◽  
Model Material ◽  
Model Tests ◽  
Cross Wedge Rolling ◽  
Comparison Of The Results ◽  
Cracking Process ◽  
Grade Steel

This article presents the results of model tests aiming to verify the possibility of applying commercial plasticine as a model material for modelling the limits to the cross-wedge rolling process. This study presents a comparison of the results of laboratory testing and physical modelling of cross-wedge rolling (CWR) processes. Commercial plasticine was the model material used in the research to model 50HS grade steel formed in 1150 °C. The model material was cooled to 0 °C, 5 °C, 10 °C, 12,5 °C, and 15 °C. Physical modelling of neckings and slippages is only possible when the plasticine is heated to 12.5 °C prior to forming. Commercial plasticine does not enable one to model the cracking process inside the rolled element.

Characterization of temperature- and rate-dependent fracture properties of fine aggregate bituminous mixtures using an integrated numerical-experimental approach

2017 ◽  
Vol 180 ◽  
pp. 195-212 ◽  
Author(s):  
Francisco Thiago Sacramento Aragão ◽  
Gustavo Adolfo Badilla-Vargas ◽  
Diego Arthur Hartmann ◽  
Alex Duarte de Oliveira ◽  
Yong-Rak Kim
Keyword(s):  
Experimental Approach ◽  
Fine Aggregate ◽  
Fracture Properties ◽  
Bituminous Mixtures ◽  
Rate Dependent
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