GOALI/Collaborative Research: Topology Optimization for Additively Manufactured Metal Castings

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

This Grant Opportunity for Academic Liaison with Industry (GOALI) Program collaborative research award will develop an integrated design-manufacture framework by coupling topology optimization design methods with additive manufacturing processes. Topology optimization is a systematic, computational tool for designing high performance devices and components. Topology-optimized designs, however, are often geometrically complex and thus difficult, if not impossible, to fabricate with traditional manufacturing processes. Additive manufacturing is arising as a potential means for overcoming this obstacle, as its layer-wise fabrication approach enables the creation of geometrically complex components without negatively affecting production cost or throughput. However, despite this natural synergy, additive manufacturing and topology optimization approaches have not yet been integrated into a comprehensive design-manufacture framework. Without this integration, topology-optimized designs may be incompatible with additive manufacturing and require tedious and potentially deleterious post-process alterations to conform to manufacturing restrictions. The primary goal of this research is thus to optimize parts for as-built conditions by (i) identifying, characterizing, and understanding the aspects of an additive manufacturing process that impose constraints on part geometry and (ii) advancing topology optimization methods to incorporate these constraints. Thus the work will substantially improve both the efficiency of the engineering design process and the efficacy of the resultant engineered artifacts. The integrated design-manufacture optimization capability will be of considerable benefit to a broad range of industries, including automotive, agricultural, and aerospace where (for example) the realization of lightweight large-scale components could lead to substantial energy savings. The multidisciplinary research team will also create integrated educational modules and provide research opportunities for underrepresented groups. As manufacturing constraints are specific to each additive manufacturing process, the research team will focus on designing components to be manufactured via the 3D sand printing process in which metal parts are made by casting molten metal into 3D printed sand molds. The team will identify, characterize, and quantify the aspects of this additive manufacturing and metal casting process chain that impose constraints on component geometry and mathematically incorporate these constraints into the topology optimization method. The topology optimization approach will have roots in projection-based algorithms where manufacturing design variables are coupled to the physical and analysis spaces to naturally achieve manufacturability. Maintaining rigor in the design framework will facilitate extension to other
materials and additive manufacturing processes. The team will design, fabricate, and experimentally test an engineered component for a case-study (provided by the industrial partner) to validate the developed design-manufacture framework.