SELECTIVE DIRECTIONAL REINFORCEMENT OF STRUCTURES FOR MULTI-AXIS ADDITIVE MANUFACTURING

Additive manufacturing has become a well-recognized method of manufacturing and has steadily become more accessible as it allows the designer to prototype ideas, products and structures unconceivable with subtractive manufacturing techniques for both consumer grade and industrial grade applications. In general, additively manufactured parts have reduced mechanical properties in the build direction of the print. Moreover, for shell-like structures, buckling is a dominant failure mode when loaded in compression, which introduces additional bending stresses in the interface between two subsequently printed layers. There is a need for reinforcement of both the material and the structures. A promising solution to the above mentioned problems is addition of local reinforcements constructed in the build direction of the base geometry. In this paper, a solution for these process defects and structural instabilities is proposed through modification of toolpathing and addition of both global and local features with multi-orientation slicing techniques. Designed for use with the broad range of capabilities of modern industrial robotics, a 6-axis directional reinforcement can be added to various types of base geometries. Through examples, two fundamental cases are elaborated: an example of the multi-axis deposition is discussed in this paper by adding a predefined feature to the side of existing geometry and in a second case, a set of global stiffeners is added to a base geometry. The methods discussed in this paper show great promise for additive manufacturing on 6 degree of freedom platforms.