Equal distance offset approach to representing and process planning for solid freeform fabrication of functionally graded materials

This paper deals with the representation and process planning for solid freeform fabrication (SFF) of 3D functionally graded material (FGM) objects. A novel approach of representation and process planning for SFF of FGM objects, termed as equal distance offset (EDO), is proposed. In EDO, a neutral arbitrary 3D CAD model is adaptively sliced into a series of 2D layers. Within each layer, 2D material gradients are designed and represented via dividing the 2D shape into several sub-regions enclosed by iso-composition contours. If needed, the material composition gradient within each of the sub-regions can be further specified by applying the equal distance offset algorithm to each sub-region. Using this approach, an arbitrary-shaped 3D FGM object with linear or non-linear composition gradients can be represented and fabricated via suitable SFF machines.