An Experimental Investigation of the Mechanical Behavior of 3D Printed Structures As a Function of Manufacturing Process Decisions

Abstract

When using additive manufacturing (AM) systems to fabricate functional parts built up in a layer-by-layer fashion, designers are required to make numerous decisions with respect to manufacturing processes parameters that can have significant impacts on how the resulting parts will perform under loading. One such parameter of interest is the orientation of the part within the build volume of the AM system utilized during fabrication. This parameter is important because the choice of build angle will directly impact how applied loads are transmitted to the bonded layers of the finished part. This paper presents the results of an experimental study specifically designed to explore this important factor and its effect on several key mechanical properties, including bending stiffness, ultimate strength, and toughness. This study consisted of printing and testing a large set of simple functional parts using a wide variety of build angle geometries, in addition to also considering other common process parameters focused on by previous studies. This study considered parts produced using two different AM technologies (material extrusion and vat polymerization), and multiple printing materials, in order to generate a dataset that can be used to inform the modeling and design of functional parts to be manufactured via various AM systems. The results produced show general agreement with previous similar studies, and the effects of build orientation present in the dataset generated clearly show the need for designers to consider this important parameter carefully when designing parts for AM applications. The results of this study also demonstrate the need for continued research on this critical topic to the field of AM in general.