SOLIDWORKS Plastics: What the Mesh?

SOLIDWORKS Plastics is a powerful tool for validation of your injection molded parts. One of the earliest steps in the process though can often prove to be challenging: creating the mesh. Without a proper mesh, our results can be inacurate, so let’s talk briefly about the mesh types.

SOLIDWORKS Plastics has a robust auto-mesher. It is used to create two different types of meshes: Shell and Solid. Each has their pros and cons, and therefore have different uses.

Shell Mesh

We always start by creating a shell mesh, also known as a surface mesh. Shell meshes are 2D in nature, and are given a thickness based on a shell thickness factor, automatically read from the thickness of the part. As a result, these elements generate very quickly, and solve times are much faster due to fewer, simpler elements.

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Generally speaking, shell meshes provide a nice balance between good accuracy, and reasonable solve times. They are ideal for thin-walled, uniform thickness parts, like pictured above. This is often a design criteria for injection molded parts anyways, so shell meshes can be used quite widely.

Solid Mesh

After generating a surface mesh, we have to option to transform it to a solid mesh. Solid meshes create additional 3D elements through the thickness of the part. There are a variety of options for element shape: tetrahedral or hexahedral, as well as subsets of hexahedral such as voxel, marching, and non-orthogonal voxel.

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Solid meshes are a must for thicker parts, as they accurately generate elements through the thickness. Realistically, they work well regardless of model geometry. They are preferred as well for parts that are more complex, and have intricate geometry even if they are thin walled.

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Solid elements provide a great deal of accuracy, however they can sacrifice quite significantly in terms of solve times. The number of elements, as well as the complexity of those elements drastically increase when transforming from a shell to solid mesh. As a result solve times can easily double, or more. However, there are almost no assumptions to make with solid meshes, so they can be safer.

Selecting the correct mesh can be key to obtaining accurate results. With SOLIDWORKS Plastics, we have a variety of different options to ensure any design can be validated quickly and easily.