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Asphalt mixture compaction in gyratory compactor using bullet Physics engine
Published in A. Kumar, A.T. Papagiannakis, A. Bhasin, D. Little, Advances in Materials and Pavement Performance Prediction II, 2020
Satyavati Komaragiri, Alex Gigliotti, Syeda Rahman, Amit Bhasin
Height of the asphalt mixture sample was tracked in the simulation along with the number of gyrations of the compactor to obtain the densification curve. The curves obtained from the compaction under these three different scenarios were then compared to evaluate the sensitivity of the asphalt mixture compaction simulation with respect to the gyratory angle. These curves are shown in Figure 4.
Investigation of motion of coarse aggregates in asphalt mixture based on virtual simulation of compaction test
Published in International Journal of Pavement Engineering, 2020
Weidong Liu, Ying Gao, Xiaoming Huang, Limin Li
Choosing simple and favourable contact models is a key step to establish a micromechanical modelling of asphalt mixture with DEM since it can affect significantly the validity and rationality of numerical simulations. Burgers model has become a widely utilised contact model in the discrete element modelling of asphalt mixture (Ma et al.2017), while it can be employed to analyse time-dependent behaviour and investigate the property of visco-elastic–plastic of asphalt mixture during compaction process (Micaelo et al.2011, Chen et al.2012, 2013). It indicated that the simulation results were consistent with the laboratory tests. According to the asphalt mixture components, there are three different types of contact behaviour which are contacts between coarse aggregates, within asphalt mastic and between coarse aggregates and asphalt mastic. Hereon, the inseparable and uncrushable clumps simulated coarse aggregates that were regarded as elastic materials. Based on the previous studies (Micaelo et al.2011, Chen et al.2012, 2013), Burgers model is used to simulate asphalt mastic, as shown in Figure 4. Figure 5 shows the different contact models within asphalt mixture. During compaction, asphalt mixture has a viscous–elastic–plasticity property in reality. Assuming that asphalt mixture is viscoelastic in DEM model simplifies the contact model. The contact model simplification also has been employed in recent DEM compaction simulation with good results (Micaelo et al.2011, Chen et al.2012, 2013). Therefore, the asphalt mixture was characterised with Burgers model in DEM model.
Investigation of asphalt joint compaction using discrete element simulation
Published in Road Materials and Pavement Design, 2019
Ehsan Ghafoori Roozbahany, Manfred N. Partl
Proper compaction has always been one of the most decisive phases that can highly affect the quality of flexible pavements and, especially, asphalt joints. Most frequently the compaction of the joints starts from the cold towards the hot side of the joint (Figure 3(a)); this technique is normally done for providing better evenness at the joint location. However, compacting from the hot towards the cold side (Figure 3(b)) has been recommended (e.g. Kandhal & Mallick, 1997; Ghafoori Roozbahany, Partl, & Witkiewicz, 2013) as an effective way to create the flow of hot asphalt mixture aggregates towards the joint interface, leading to higher density and improving the performance of the joints. The flow phenomenon during compaction of asphalt joints was further investigated in series of separate studies leading to developing a compaction flow test, called CFT (Ghafoori Roozbahany & Partl, 2016; Ghafoori Roozbahany, Partl & Guarin, 2017a). CFT is a simple compaction simulation that takes into account not only vertical but also lateral movements of aggregates during the initial stages of the compaction when large deformations take place. Using the CFT along with the X-ray CT images, Figure 4, suggests that the rearrangements and flow of particles in both vertical and lateral directions have to be taken into account when investigating compaction of asphalt pavements especially at the joint locations. Although it is possible with the CFT and the X-ray imaging to capture the rotations of aggregates, the focus of the CFT has been more on the translational movements of the aggregates than their rotations for practical measurement reasons.
Influence analysis of different compaction degrees on the fatigue performance for stranded copper power conductors
Published in Ships and Offshore Structures, 2022
Kaien Jiang, Yong Bai, Peng Cheng
Firstly, to obtain an accurate simulation of wire deformation, the conductor compaction procedure was simulated by using FEM. The results of the compaction simulation were compared with real conductors and wires in respect of deformation shapes. Then, the parameter analysis of the compaction degrees was conducted. Lastly, for convenient application in cable design, the predicted fatigue life table of the conductor tested in this paper was proposed.