Tips & Tricks

The transient method – the third out of three methods to simulate the heat effects of welding

In order to meet different requirements from first design to start of production, three different methods are available in the Virtual Welding & Assembly Suite from ESI. The third one – the transient method – is used when not only distortion but also residual stresses and microstructure need to be evaluated. The part size allows running a heat source gradually. Compare it with a formability evaluation in sheet metal forming. A motorcycle rim may serve as an example.

The instantaneous method – the second out of three methods to simulate the heat effects of welding

In order to meet different requirements from first design to start of production, three different methods are available in the Virtual Welding & Assembly Suite from ESI. The second one – the instantaneous method – is used when not only distortion but also residual stresses and micro-structure needs to be evaluated, but welded designs are so huge that it would make no more sense to use a classic transient method with a moving heat source – the simulation time would be too long. Compare it with a feasibility evaluation in sheet metal forming. A frame as produced in machine building, with more than 100 welds, may serve as an example.

The shrinkage method – the first out of three methods to simulate the heat effects of welding

In order to meet different requirements from first design to start of production, three different methods are available in the Virtual Welding & Assembly Suite from ESI. The first one – the shrinkage method – is used in the feasibility and planning phase. Goal is to get as fast as possible an estimation. Compare it with a one-step method in sheet metal forming.

Working with Solids in CFD-GEOM - Part 1: Boolean Operations

Given that today’s users may import several complex parts into CFD-GEOM, this tip will demonstrate how to use the Solid Boolean Union Option to combine several parts into one.

Using the BC/VC Queries tool in CFD-GEOM

Have you ever whished that you could blank/unblank or pick/unpick only interfaces in a CFD-GEOM model? You can now with the BC/VC Queries tool. This tool allows you to pick, unpick, blank or unblank all the interfaces of the current model based on the interface type (Fluid/Fluid, Fluid/Solid, etc.).

How to create Pyramid cells on structured-unstructured domain interfaces in CFD-GEOM

CFD-GEOM can be used to construct a variety of cell shapes: quadrilaterals (2D) and hexahedrals (3D) for structured meshes; triangles (2D) as well as tetrahedrals and polyhedral/honeycomb (3D) for unstructured meshes; prisms and pyramids (3D) for semi-structured meshes.

New Exposed Boundaries Visualization tool in CFD-GEOM

One of the various new features introduced in CFD-GEOM V2009.2 is the ‘Exposed Boundaries’ visualization tool. This tool allows users to quickly visualize those areas where closure problems remain in an otherwise closed and “watertight” model.

Repairing Imported CAD Geometries in CFD-GEOM

In most cases, importing CAD files in CFD-GEOM results in a clean geometry that can be directly used for further processing and/or meshing. However, for complex models, it is possible that the imported geometry has missing, untrimmed or defective surfaces that need to be manually repaired.

Butterfly Faces Meshing Tool in CFD-GEOM

In CFD-GEOM, a convenient meshing tool called "Butterfly Faces" allows the user to quickly and automatically create a structured mesh for circular topologies. The resulting mesh consists of 5 structured faces (4 sides and 1 core) inside a circle. Parameters are available to set the size of the core and the mesh density.

Exporting STL Files From CFD-GEOM

A CFD simulation process starts from an accurate representation of the boundaries that usually originates directly from CAD systems. STL and IGES are two of the most common output formats used as a starting point for mesh generation. STL (StereoLithography) files represent 3D surface geometries using a triangular mesh allowing unambiguous transfer of files from one system to another.