One of the key shape feature types is the "shellable" feature. This is a material volume that you can apply a wall thickness to, thus defining an internal boundary and creating an internal spatial volume.
The Shell Properties command assigns a wall thickness to an active body, making it hollow, thus making the Shellable volumes hollow that are in the body. The command not only specifies the wall thickness, but you can also use it to remove one or more faces from the shelled volume, as shown in the following image:
All removed faces can be restored and the wall thickness can easily be changed at any time by using the Shell Properties command . In addition, you can specify different wall thicknesses for each face.
From R16 onwards, you can specify whether the thickness is an inside thickness or an outside thickness in Wall Direction while editing the shell property. The default will be inside thickness, and the default value will be 0 mm.
When an "Inside" wall direction is specified, the third tab name becomes "Core". When an "Outside" wall direction is specified, the tab name becomes "Cavity".
specify "Inside" wall direction and 0mm thickness, the shellable
features generates the outside with the positive volumes and no core
will be removed.
After a shellable volume is shelled, only features that have behaviors that function within internal volumes, such as ribs, can penetrate the shell (or internal) boundary. Thus, features such as boss and reinforcement cannot penetrate the shell because their behaviors are to add material volume to the outside of another material volume.
In some specific cases, the application cannot create non-offsetable surface in the shell computation. An error message then appears informing you that the resulting geometry cannot be assembled. These errors are difficult to manage by the user because they generally involve several shellable features and the shell properties. The Shell Update Assistant is to help the user identify the cause of an update error in the shell computation and then to solve the error.
Core (Specific to Inside wall direction)
The Shell Update Assistant is a new tab, labeled Core, that is added to the Shell properties dialog. It displays the list of shellable features and how each contributes to the inner shape of the shell. In case of an update error in the shell property, the Shell Update Assistant allows the user to quickly identify which shellable feature(s) caused the error, to activate or deactivate shellable features, to change their core contribution type, and to try another update.
3 types of core definitions for a shellable feature: