Investigation of variations in performance properties of asphalt concrete using image-based finite element model

Karakaya, Yalçın
The objective of this study is to evaluate variations in performance properties of asphalt concrete using a two-dimensional image-based finite element model. Two different asphalt mixtures are used in both laboratory tests and in FEM analyses representing different conditions. A flatbed scanner is then used to capture cross-sectional images of the samples and various image processing techniques are applied to prepare the images for FEM. A unique image vectorization method has been developed to transform cross-sectional images into the finite element mesh to minimize computational time in FEM, where AC is modeled as a composite material consisting of individual components of aggregate and asphalt binder. In the experimental program, three different testing programs; resilient modulus, repeated creep and indirect tensile fatigue tests are conducted to obtain different performance indicators. The laboratory experiments are performed using ten replicates, to establish the variability in performance properties. Sample variability is also studied in the FEM for identical specimens by changing their microstructures using a previously developed redistribution algorithm. Finally, the performance indicators obtained from the laboratory tests and the FEM analyses are compared to evaluate the variability in the performance tests. Various results show that the two-dimensional finite element model created in this study works successfully for two completely different mix designs under different test conditions. Furthermore, with the particle redistribution method, the inherent variability of the asphalt concrete on the test results is identified and it was found to correspond to values as low as about one eighth.


Prediction of automobile tire cornering force characteristics by finite element modeling and analysis
Tönük, Ergin; Ünlüsoy, Yavuz Samim (2001-05-01)
In this study, a detailed finite element model of a radial automobile tire is constructed for the prediction of cornering force characteristics during the design stage. The nonlinear stress-strain relationship of rubber as well as a linear elastic approximation, reinforcement, large displacements, and frictional ground contact are modeled. Validity of various simplifications is checked. The cornering force characteristics obtained by the finite element tire model are verified on the experimental setup const...
Consideration of spatial variation of the friction coefficient in contact mechanics analysis of laterally graded materials
Dağ, Serkan (2016-01-01)
This paper presents a new analytical approach for sliding contact analysis of laterally graded materials, which allows taking into account the spatial variation of the friction coefficient. The method is developed by considering a sliding frictional contact problem between a laterally graded elastic medium and a rigid flat punch. Governing partial differential equations entailing the displacement components are derived in accordance with the theory of plane elasticity. General solutions are determined and b...
Investigation of the impact of aggregate segregation on rutting resistance of asphalt concrete
Yücel, Ayhan Öner; Güler, Murat.; Department of Civil Engineering (2019)
In this study, effect of aggregate segregation on rutting resistance of asphalt concrete is investigated using laboratory compacted specimens. A procedure to determine inhomogeneity level is proposed using 2-dimensional cross section images of asphalt concrete specimens. A redistribution algorithm is developed to assess the aggregate distribution characteristics and inhomogeneity index of the cross sectional images. In order to simulate field conditions, specimens are produced in two different groups: (i) w...
Investigation of low temperature cracking in asphalt concrete pavement
Qadir, Adnan; Güler, Murat; Department of Civil Engineering (2010)
In this study, low temperature cracking of asphalt concrete is investigated based on a laboratory experimental program including the design variables of aggregate type, gradation, asphalt content, binder grading, binder modification, and the experimental variables of cooling rate, and specimen size. The design of experiment is proposed according to the fractional factorial design principles to reduce the required number of test specimens. Mix designs are performed according to the Superpave mix design guide...
Elfarra, Monier A.; Akmandor, I. Sinan; Sezer Uzol, Nilay (2011-03-25)
The main purpose of this paper is to optimize winglet geometry by using CFD with Genetic Algorithm and study its effects on power production. For validation and as a baseline rotor, the NREL Phase VI wind turbine rotor blade is used. The Reynolds-Averaged Navier-Stokes equations are solved and different turbulence models including the Spalart-Allmaras, k-epsilon Launder-Sharma, k-epsilon Yang-Shih and SST k-omega models are used and tested. The results of the power curve and the pressure distribution at dif...
Citation Formats
Y. Karakaya, “Investigation of variations in performance properties of asphalt concrete using image-based finite element model,” Ph.D. - Doctoral Program, Middle East Technical University, 2022.