Application of Discrete Element Modeling Techniques to Predict the Complex Modulus of Asphalt–Aggregate Hollow Cylinders Subjected to Internal Pressure

You, Zhanping; Buttlar, William G.

doi:10.1177/0361198105192900126

Cited by 38 publications

(24 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The parameters can be predicted by DEM, and mechanism of the movement of granules from the mesoscopic angle can be analyzed. Moreover, the relationship between the macromechanics and mesomechanics behaviorsc an be established by comparing with the test data, thus guiding the design of granular materials [19][20][21][22][23]. Golchert et al [24] studied the effectsoft he form and structure of granules on the fracturesb yD EM.…”

Section: Experimentals Tudy and Dem Simulation Of Micro-macro Behaviomentioning

confidence: 99%

Experimental Study and DEM Simulation of Micro–Macro Behavior of TATB Granules During Compaction Using X‐ray Tomography

Dai

Zhang

Lan

et al. 2015

Propellants Explo Pyrotec

View full text Add to dashboard Cite

[a] 1Introduction TATB is ac ommonly used insensitive explosive with high energy.T he main characteristics of TATB are its relatively low mechanical sensitivity and thermals ensitivity,a nd it is also safe and stable. In its actuala pplication, ap olymer binder in ac ertain proportion is often added to TATB, and then it can be compressed to ap olymer-bonded explosive (PBX) under high temperature and high pressure conditions. WhenP BX is compressed, the TATB granules undergo friction, extrusion, and propagation of pressure, thus affecting the microstructure and internal stress distribution of the compression molding [1,2].T he granule microstructure comprises the size, shape, and surface feature of the granules, connectionb etween the granules, the permutation and combinationo ft he granules,q uantitative relationship, and the distance between the granules, pore size, and distribution characteristics.T hesem icrostructuresa re important factors to confirm the physical, mechanics, and other characteristics of the explosivea nd will directly affect the density distribution and stress concentration of PBX,t hus affecting the safety performance and usability of the explosive. To investigatet he relationship betweent he changes in the microstructure causedb yc ompression and macroperformance, the various characteristics of microstructure should be accuratelye valuated. Electronm icroscope, matchingr efractive microscope, and polarizing microscope, etc. have beenu sed to achieve this objective [3][4][5][6][7][8][9][10][11][12][13][14].T hese methods cannot be used to observe the evolution of the internal structure,a nd some of them may cause secondary damage. With the development of controlt echnology and computer technology,X -ray computed tomography has been used to study and monitor the microstructure of explosives. Zhang et al.[15] studiedt he feature of RDX crystals under different pressures by mCT and discussed the issues including the displacement and breakage of the crystals, as well as the compressed density and distribution, gap filling, and microcrack distribution. They also obtained the completet hree-dimensional (3D) information of the microstructure of explosivew ith TATB radicals by moldp ressing at one-wayt emperature by CT [16].L an et al. [17], studied the microcosmic distributiono ft he internal crack of explosive and the healing statusbefore and after the disposal by the warm-pressing agingt reatment by CT.T ian et al. [18] observed the solidificationo fe xplosivea nd analyzed the distribution of internal thermal stress duringt he solidification. The above studies mainly evaluated the characteristics of explosiveb efore and after molding.C ombined the advantageso fC Tt echnology and the results of the studies on 3D systems, dynamico nline testing is also needed to study the characteristics of granules during the compression,i ncluding the morphological characteristicso f Abstract:I nt his study, an oninvasive experimental method and ad iscrete element method (DEM) model were used to investigate t...

show abstract

Section: Experimentals Tudy and Dem Simulation Of Micro-macro Behaviomentioning

confidence: 99%

Experimental Study and DEM Simulation of Micro–Macro Behavior of TATB Granules During Compaction Using X‐ray Tomography

Dai

Zhang

Lan

et al. 2015

Propellants Explo Pyrotec

View full text Add to dashboard Cite

show abstract

“…Several recent studies have used the DEM to characterize the behavior of asphalt mixtures under different laboratory loading conditions and using different elastic and viscoelastic material models (9)(10)(11)(12)(13). DEM is a finite difference scheme developed to study the interaction between discrete particles.…”

Section: Discrete Element Modeling Of Asphalt Mixturesmentioning

confidence: 99%

Modeling and Experimental Evaluation of Influence of Aggregate Blending on Asphalt Mixture Strength

Mahmoud

Masad

Nazarian

et al. 2010

Transportation Research Record

View full text Add to dashboard Cite

Only a few studies and guidelines are available that address the functional and structural performance issues associated with blending of aggregates in asphalt pavement layers. As an example, the Texas Department of Transportation (DOT) has developed guidelines for blending aggregates to meet specified requirements for skid resistance of asphalt pavement surfaces. Using the basis of polishing resistance and durability, the Texas DOT classified aggregates as Class A, B, or C, with Class A having the most desirable properties. The Texas DOT permits the blending of Class A and Class B aggregates; however, the blend should meet Class A requirements, and at least 50% by weight of the material retained on the No. 4 sieve needs to come from the Class A aggregate source (6). Pan et al. (7 ) and Tutumluer and Pan (8) studied the effect of blending different types of aggregates on unbound base layers by evaluating their resilient behavior, strength, and permanent deformation. In those studies, uncrushed gravel was blended with five other types of aggregates: crushed granite, crushed limestone, crushed gravel, slag, and sandstone. The uncrushed gravel blending percentages were 0%, 17%, 33%, 50%, and 100% of total weight. The studies demonstrated how blending can enhance the behavior of the uncrushed gravel.Despite the apparent economic and performance benefits that can be realized from aggregate blending, no studies have been published in the open literature on the impact of blending on mechanical properties of asphalt mixtures. Such studies are needed, to develop guidelines for the recommended percentages of blending to optimize mixture performance. OBJECTIVES AND TASKSThe primary objective of this paper is to present an approach to evaluate the mechanical properties of asphalt mixtures that consist of different percentages of aggregate types. This objective is achieved through the following tasks:1. Develop a model that relies on the capabilities of the discrete element method (DEM) and image analysis techniques that represent the internal structure of asphalt mixtures composed of different percentages of aggregates.2. Use the model results to develop simple charts for different types of mixtures to estimate the influence of using various percentages of high-and low-quality aggregates on mixture strength. These charts can be used to determine the optimum percentage of blended aggregates such that the desirable mixture strength is achieved.3. Verify the model results through comparisons with different laboratory tests (tensile strength, Hamburg wheel-tracking device, dynamic modulus, and flow time).Performance of asphalt mixes is vastly influenced by their aggregate properties. The depletion and the high cost of transportation of highquality aggregates prompt the use of locally available aggregate sources. One approach that has been followed by state highway agencies and contractors to encourage the use of locally available aggregate sources is to blend low-and high-quality aggregates. However, no method is available to th...

show abstract

“…The digital sample generation was conducted on a sectioned asphalt mixture specimen shown in Figure 6. This specimen is a 19 mm (nominal maximum aggregate size) mixture used in studies by You and coworkers 4, 8, 51. The image was obtained by a high‐resolution optical scanner and was preliminarily processed with imaging technology.…”

Section: Microstructure Of the Stone‐based Materials And Digital Smentioning

confidence: 99%

“…A number of researchers have developed micromechanical models to predict the fundamental properties of the asphalt mixtures based upon those of the phase constituents 1–5. Buttlar and You employed discrete element models to characterize the properties of asphalt mixtures 6–8. Guddati et al 9 presented a random truss lattice model to simulate microdamage in asphalt concrete.…”

Section: Introductionmentioning

confidence: 99%

Micromechanical viscoelasto‐plastic models and finite element implementation for rate‐independent and rate‐dependent permanent deformation of stone‐based materials

Dai

2009

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

SUMMARYThis paper presents parallel and serial viscoelasto-plastic models to simulate the rate-independent and the rate-dependent permanent deformation of stone-based materials, respectively. The generalized Maxwell viscoelastic and Chaboche's plastic models were employed to formulate the proposed parallel and serial viscoelasto-plastic constitutive laws. The finite element (FE) implementation of the parallel model used a displacement-based incremental formulation for the viscoelastic part and an elastic predictor-plastic corrector scheme for the elastoplastic component. The FE framework of the serial viscoelasto-plastic model employed a viscoelastic predictor-plastic corrector algorithm. The stone-based materials are consisted of irregular aggregates, matrix and air voids. This study used asphalt mixtures as an example. A digital sample was generated with imaging analysis from an optically scanned surface image of an asphalt mixture specimen. The modeling scheme employed continuum elements to mesh the effective matrix, and rigid bodies for aggregates. The ABAQUS user material subroutines defined with the proposed viscoelasto-plastic matrix models were employed.The micromechanical FE simulations were conducted on the digital mixture sample with the viscoelastoplastic matrix models. The simulation results showed that the serial viscoelasto-plastic matrix model generated more permanent deformation than the parallel one by using the identical material parameters and displacement loadings. The effect of loading rates on the material viscoelastic and viscoelasto-plastic mixture behaviors was investigated. Permanent deformations under cyclic loadings were determined with FE simulations. The comparison studies showed that the simulation results correctly predicted the rateindependent and rate-dependent viscoelasto-plastic constitutive properties of the proposed matrix models. Overall, these studies indicated that the developed micromechanical FE models have the abilities to predict the global viscoelasto-plastic behaviors of the stone-based materials.

show abstract

Application of Discrete Element Modeling Techniques to Predict the Complex Modulus of Asphalt–Aggregate Hollow Cylinders Subjected to Internal Pressure

Cited by 38 publications

References 5 publications

Experimental Study and DEM Simulation of Micro–Macro Behavior of TATB Granules During Compaction Using X‐ray Tomography

Experimental Study and DEM Simulation of Micro–Macro Behavior of TATB Granules During Compaction Using X‐ray Tomography

Modeling and Experimental Evaluation of Influence of Aggregate Blending on Asphalt Mixture Strength

Micromechanical viscoelasto‐plastic models and finite element implementation for rate‐independent and rate‐dependent permanent deformation of stone‐based materials

Contact Info

Product

Resources

About