Road Construction Technology - SimulationCopyright: © isac
The Road Construction Technology Simulation research group at the Institute of Highway Engineering at RWTH Aachen University focuses on machine-material interaction in paving processes, cyber-physical systems as a starting point for process optimization, and multiscale simulations of the mechanical behavior of asphalt mixes.
Research Focus in Traffic Construction Technology - Simulation
Various machines and materials are used in the paving of asphalt mix in pavement structures. The term machine-material interaction refers to the interaction of these components, or more precisely, the interaction between the paver or roller compactor and the asphalt mix. During the paving phase, the rotating auger of the paver distributes the asphalt mix across the entire width of the road. During the compaction phase, different forces act on the surface: first, as soon as the paver's screed plate or the roller's steel drum comes into action, a vertical compressive force acts on the material to compact it. In addition, as the compacting machine moves forward, a horizontal shear force is also generated from the frictional behavior between the machine and the material. At the point of contact between the aggregates, a shear force can also be generated, causing the aggregates to be rearranged, which, among other things, reduce the volume. These complex processes are of great importance for the development of durable pavements. The interactions between machine and material are therefore the focus of research, with the aim of better understanding the processes and optimizing manufacturing methods.
A cyber-physical system (CPS) is a computer system in which a mechanism is controlled or monitored by means of computer-based algorithms. Both the physical and the software components are closely interconnected. They can be deployed at different spatial and temporal scales: Their mode of interaction can change depending on the context and adapt accordingly. Cyber-physical systems unite and combine numerous approaches from a wide range of research fields, such as cybernetics, mechatronics, design, and process economics.
One possible application example of cyber-physical systems in road engineering is the optimization of paving processes. This can start with the microstructure of the construction materials as well as with the manufacturing machines. The goal is to process an ideal construction material under the best possible conditions - using real-time adjusted settings of the construction equipment to achieve a result of maximum quality. In the long term, such construction process optimization is quite conceivable, but at present a considerable amount of basic research is still required.
Multiscale simulation makes it possible to study the detailed mechanical, thermal or hydraulic responses of asphalt materials at different length scales. This is based on numerical simulations such as the finite element method, the discrete element method and the molecular dynamic method. The different length scales can be defined from the molecular scale to the nanoscale, the microscale and the macroscale. This is of particular benefit because some significant phenomena can be more accurately represented at smaller scales. Another advantage of multiscale simulation is that it captures processes that cannot be replicated by laboratory experiments. In addition, cross-scale relationships can be established and deeper insights into the multiscale behavior of asphalt materials can be produced. This can also serve as a starting point for developing effectively improved asphalt pavements.
5 Q uestions about Traffic Construction Technology - Simulation and its research focus at ISAC, answered by Dr.-Ing. Pengfei Liu.