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The assessment and representation of intricate design and simulation results for organic geometries through traditional devices (tablets, computers, phones) possess a set of significant limitations. Consequently, identifying potential manufacturability, design issues, and opportunities for design enhancements remains challenging in the early design stage. The inability to identify these possible areas often leads to time-consuming and costly design revisions and iterations. In contrast, Virtual Reality (VR) offers many benefits over the conventional 3D computer-aided design (CAD) environment, particularly regarding visualization and analysis of complex organic geometries. The advantages of VR may be more visible as designs become more organic or complex. This thesis aims to investigate and develop an immersive environment that enables designers and engineers to explore complex organic geometries. This thesis focuses on generating an Immersive Virtual Reality (ImVR) environment that could allow designers to evaluate and identify critical design areas of a part model based on the design for additive manufacturing (DfAM) parameters. Custom Python scripts and Visualization Toolkit (VTK) algorithms perform surface and volume rendering across the CAD model in the virtual environment. Two case studies of different organic designs with tools and an immersive visualization environment are presented to analyze the effect of immersive design analysis of a CAD model. The ImVR toolset also includes a collaborative multiplayer feature and an artificial intelligence (AI) chatbot powered by ChatGPT. The chatbot can provide real-time guidance to users within the immersive environment, while the collaborative feature enables multi-user interaction and visualization in the immersive environment.

With more efficient computational capabilities, the use of topology optimization (TO) is becoming more common for many different types of structural design problems. Rapid prototyping and testing is often used to further validate optimized designs, but depending on a design’s complexity, the structural behavior of physical models can vary significantly compared to that of their computational counterparts. For graph-based topologies such differences are caused, in part, by a need to realize finite-thickness structures from the infinitely thin geometries described by graph theory. Other differences are caused by limitations on manufacturing processes such as the need to fabricate large models from smaller components. While additive manufacturing (AM) can be more conducive for fabrication of complex topologies, its limitations are generally less understood than those for traditional subtractive manufacturing processes. Understanding and incorporating limitations on AM into a TO process in the form of added constraints would allow the algorithm to produce not only optimal designs, but also those that are feasible for AM.In this work, two specific AM constraints are characterized for Lindenmayer system (L-system) graph-based topologies of a multi-material, diamond-shaped, morphing airfoil in supersonic flow. One constraint is related to the feasible generation of thick structural members from the infinitely thin beams of graph-based topologies. To characterize the effects of geometric overlap, structural behavior of finite element models made of lower-fidelity beam elements is compared to that of finite element models made of higher-fidelity volume elements. Results indicate that at intersections where 10% or more of a member’s length is overlapped, there will be significant variations in stress and effective torsional stiffness when thin members are converted to thick members. The second AM constraint characterized in this work is related to partitioning of large models that exceed a 3D printer’s build size. Finite element analyses and laboratory experiments indicate that differences in localized displacements and distribution of maximum principal strain will occur when partitioning a physical model derived from the multi-material graph-based topologies. Partitioning perpendicular through structural members is recommended since it proved to be the most consistent method employed in the studies in terms of affecting structural behavior of the geometry.

The term Additive Manufacturing (AM) is used to describe several manufacturing technologies that share the same basic principle of producing parts directly from their CAD models without the need for special tooling, by adding material selectively one layer at a time. Current research focuses on one such technology called Selective Laser Sintering (SLS) where thin layers of powdered thermoplastic material are fused using a laser beam. With no part-specific tooling required, the product development cycle is drastically shortened. This lack of tooling, coupled with freedom of placement of material, opens the door to several design opportunities unique to AM such as increased geometrical design freedom and the ability to manufacture low production volumes economically. Gradual improvements in process accuracy and selection of materials over time have resulted in a shift in application of AM from rapid prototyping to direct manufacturing and even ‘democratization’ of the product development process in which even non-professional users can rapidly manufacture products as long as there is a CAD model for the part. However, the move to direct manufacturing of end-use parts also means that part quality in terms of conformance to product specification becomes important for the product to successfully perform its function. The research in this thesis is focused on documenting these manufacturability capabilities and limitations for Selective Laser Sintering. It focuses specifically on thermoplastics, especially Nylon 12 polyamide materials known by the trade names PA 2200 and Duraform PA. While several design resources have been created based on industry best practices developed through experience, they are scattered throughout the literature and are not readily available to designers. It is also difficult to compare and draw quantitative inferences from existing guidelines as they are developed independently under dissimilar process conditions. Therefore, a prime focus of this research is to synthesize and compile existing guidelines into a comprehensive document. The first objective of this research is to compile a user-friendly resource, in the form of design principles and guidelines, to help designers make early process selection decisions, optimize part quality and minimize manufacturing cost. A systematic literature review of available guidelines, exploratory studies and case studies is conducted to develop actionable design recommendations that are within the scope of the designer. The second objective of this research is to address the lack of adequate process tolerance information that can reliably predict the quality of parts produced by the selective laser sintering process. This information is important to accurately evaluate the process during early process selection. A test part is proposed to measure dimensional deviations for various features (such as holes, gaps, cylinders, walls, clearances, etc.) across a range of dimensions and along different orientations. Finally, a sampling plan that represents sources of variability in the process is put forward to collect statistical data in an economical manner.

The term Additive Manufacturing (AM) is used to describe several manufacturing technologies that share the same basic principle of producing parts directly from their CAD models without the need for special tooling, by adding material selectively one layer at a time. Current research focuses on one such technology called Selective Laser Sintering (SLS) where thin layers of powdered thermoplastic material are fused using a laser beam. With no part-specific tooling required, the product development cycle is drastically shortened. This lack of tooling, coupled with freedom of placement of material, opens the door to several design opportunities unique to AM such as increased geometrical design freedom and the ability to manufacture low production volumes economically. Gradual improvements in process accuracy and selection of materials over time have resulted in a shift in application of AM from rapid prototyping to direct manufacturing and even ‘democratization’ of the product development process in which even non-professional users can rapidly manufacture products as long as there is a CAD model for the part. However, the move to direct manufacturing of end-use parts also means that part quality in terms of conformance to product specification becomes important for the product to successfully perform its function. The research in this thesis is focused on documenting these manufacturability capabilities and limitations for Selective Laser Sintering. It focuses specifically on thermoplastics, especially Nylon 12 polyamide materials known by the trade names PA 2200 and Duraform PA. While several design resources have been created based on industry best practices developed through experience, they are scattered throughout the literature and are not readily available to designers. It is also difficult to compare and draw quantitative inferences from existing guidelines as they are developed independently under dissimilar process conditions. Therefore, a prime focus of this research is to synthesize and compile existing guidelines into a comprehensive document. The first objective of this research is to compile a user-friendly resource, in the form of design principles and guidelines, to help designers make early process selection decisions, optimize part quality and minimize manufacturing cost. A systematic literature review of available guidelines, exploratory studies and case studies is conducted to develop actionable design recommendations that are within the scope of the designer. The second objective of this research is to address the lack of adequate process tolerance information that can reliably predict the quality of parts produced by the selective laser sintering process. This information is important to accurately evaluate the process during early process selection. A test part is proposed to measure dimensional deviations for various features (such as holes, gaps, cylinders, walls, clearances, etc.) across a range of dimensions and along different orientations. Finally, a sampling plan that represents sources of variability in the process is put forward to collect statistical data in an economical manner.