Ali Shayegh is a PhD student at University College Dublin (UCD). He earned a bachelor’s degree in petroleum engineering from Shiraz University and a Master’s in mechanical engineering from Malek Ashtar University of Technology, Iran. His main research interests are in computational mechanics for the simulation of product performance, including the use of C++ programming and OpenFOAM software.
Research Interests (Lay Summary)
In our daily lives, rods are employed in a variety of ways. Although a typical rod with a circular cross-section may be the first example that comes to mind, the focus of Ali’s research is on non-circular rods, also known as profiled rods. If you take a closer look around you, you might come across several instances of their applications, such as a flat file, a blind tilt rod, or an exhaust clamp, to name a few.
From the standpoint of a rod manufacturer, the design process for a new profiled rod is lengthy, often taking a number of years. Introducing “virtual prototyping” to the design process can speed up production and lower manufacturing costs. Virtual prototyping refers to the process of simulating machinery on a computer before it is built in the real world. It also allows designers to experiment with ideas that would otherwise be unthinkable.
There are three common numerical approaches to simulate a plastic deformation problem: Lagrangian, Eulerian, and Arbitrary Lagrangian-Eulerian (ALE) approaches. Each approach has its own advantages and drawbacks.
Eulerian formulation refers to the integration of the governing equations over a fixed mesh. This approach is efficient in the case of steady forming processes; however:
- it does not predict material’s spring-back effects;
- solid boundary motion cannot be predicted accurately.
In Lagrangian formulation, a mesh is attached to the work-piece. Though this approach is incorporated successfully in a wide range of problems, it has some difficulties including:
- remeshing which is necessary if the initial mesh is severely deformed; subsequently the fields should be remapped after each mesh generation step, which in turn introduces large errors to the final results;
- volume loss is a frequent difficulty in extreme deformation.
ALE formulation, combines the two aforementioned approaches. In this approach, each solution step is divided into two steps; an updated Lagrangian step followed by an Eulerian step. The main difficulty with applying an ALE approach in 3D, is avoiding volume loss, and representing the boundary surface correctly.
This research project will address the difficulties with these approaches by looking into a number of novel approaches, including but not limited to:
- local remeshing rather than remeshing the whole domain
- incorporating an adaptive mesh along with conservative polyhedra mapping,
- and more investigation into the potentials of ALE finite volume approaches.