Full Mould Analysis
High quality mesh model is the premise and key condition to get accuracy numerical simulation results in casting process, special for FEM simulation method. However, it is usually difficult to build effective mesh model by professional casting simulation software if solid model is too complex. The meshing process is the major bottle neck problem for FEM technology in casting process simulation.
It is well known that the hexahedron element had better flow analysis result than the tetrahedron element for casting part, but thermal analysis result was almost similar. Also, the tetrahedron element still has many advantages if applied to the mould meshing. For example,
- Save model size. The tetrahedron element is easy to have a big element ratio than the hexahedron elements.
- Good geometry description for cooling channel and other components.
- Good thermal analysis capability.
- Save CPU time. Since the mould size is economic, so the CPU time of simulation is also saved.
Cast-Designer supports the mixed meshes technology. The user can set the hexahedron element for casting part and tetrahedron element for mould. More ever, in Cast-Designer, we have special technology to keep the contact nodes at the same location of the casting part and mould interface, such feature was very useful to keep the system had a good heat transference.
The mixed mesh technology in Cast-Designer. Tetrahedron mesh is used for mould to save elements numbers and hexahedron mesh used for casting to keep a good flow result. Even if in different mesh type, the contact nodes location of interface was same.
The full mould meshing and assembly could be carried out easily and it has been done in Cast-Designer in one button. There are lots of innovation technologies behind the surface interface. One of them is the re-mesh technology of different contact interface.
For mesh assembly, the user need define all the components of the die sets, such as casting, gating system and overflow system, insert and slider, fix mould and moveable mould, then start the ‘Fastmesh’ program to define the general mesh parameters, then the computer will take over all other jobs.
The mesh assembly result with very good affective ratio for the casting to full mould. The casting part with 117,336 nodes, the fix mould with 44,993 nodes and the movable mould with 55,997 nodes, plus other sliders, the global affective ratio was up to 38.2%, it was really very good .
The full mould analysis could be used for:
- A more accurate temperature analysis. It is usually necessary for the permanent mould gravity casting since the filling time was longer and the mould thickness was an important role of the heat transfer process.
- The mould cycling analysis for a stable temperature distribution during the production cycles.
- The mould thermal analysis to check the life time.
- The stress analysis to consider the full mould.
- The detail cooling system analysis.