Effectiveness of virtual models in design for additive manufacturing: a laser sintering case study Meagan R. Vaughan and Richard H. Crawford Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas, USA Abstract Purpose – Additive Manufacturing (AM) technologies have conventionally focused on producing prototypes. However, recent trends show that AM is being increasingly used for production parts. With this shift from prototypes to production parts, there is a need to determine whether established engineering design techniques can be applied to AM processes, particularly techniques characteristic of the final implementation phase such as virtual (mathematical) modeling, or whether AM process-specific adjustments must be made. Design/methodology/approach – The effectiveness of applying virtual models to design problems utilizing AM processes was addressed using two approaches in this research. Literature was first reviewed to determine the current focus of the AM industry on virtual modeling, both analytical and numerical, and its implementation. Second, experiments were conducted to validate virtual models applied to fastener mechanism designs manufactured using laser sintering (LS). Findings – Limited research has been published that demonstrates the effectiveness of applying established design techniques, particularly virtual modeling techniques, to parts manufactured with AM processes. The experimental case study has demonstrated that, for the limited cases considered, design techniques capable of accommodating the complex material properties of LS materials, such as finite element analysis, are effective methods for predicting part performance in accordance with desired outcomes. Practical implications – The research indicates that designers can focus on designing quality LS parts with existing technology and methods rather than revamping their design methods due to the introduction of a new manufacturing technology. Originality/value – This research provides support for the application of established design methods to LS AM processes; validating what has previously been an assumed part of AM. Keywords Design, Sintering, Manufacturing systems, Modelling, Production planning and control, Selective laser sintering, Production parts, Additive manufacturing, Virtual modeling Paper type Research paper Introduction Conventional uses of additive manufacturing (AM) have focused on producing parts whose primary purpose is concept demonstration (prototypes). For such applications, verifying basic functionality and fit are the primary objectives of designers. There is also an increasing trend toward using AM for the fabrication of final production parts. With this shift comes an added emphasis on predicting the behavior of manufactured parts based on the requirements of their intended applications. Of particular interest for mechanical applications is the ability to predict the strength and deformation of parts under a variety of anticipated loading conditions. In contemporary engineering, virtual models are regularly used to determine appropriate materials and dimensions for final production parts. Using the terminology of Otto and Wood (2000), these virtual models are a subset of system models with which a designer can predict product performance – both physically and theoretically. Physical models include concept models for aesthetic evaluation, targeted experimental models to test functionality, and full design and production prototypes. (Interestingly, many AM technologies were originally developed to provide rapid fabrication of physical models for design.) Virtual models include analytical models, such as closed-form equations, by which the behavior of the system can be predicted prior to manufacturing a prototype. Numerical models, such as finite element analysis (FEA), are also common for systems where closed-form equations are not readily available. In theory, established design methodologies that utilize these virtual models should be applicable to design projects implementing AM processes. However, the appropriateness of using such design techniques with AM processes has not been thoroughly verified or documented. In this paper, a survey of published literature is presented to establish the current focus of virtual modeling and its relative success in design for AM. In addition, a case study is presented where fastener mechanisms were designed using common methodologies and manufactured using laser sintering (LS). Together, these provide an The current issue and full text archive of this journal is available at www.emeraldinsight.com/1355-2546.htm Rapid Prototyping Journal 19/1 (2013) 11–19 q Emerald Group Publishing Limited [ISSN 1355-2546] [DOI 10.1108/13552541311292682] Received: 3 May 2011 Revised: 4 July 2011 Accepted: 12 July 2011 11