Chapter 3 - Digital design for AM

Research in additive manufacturing (AM) has increased the use of AM in many industries, resulting in a commensurate need for a workforce skilled in AM. In order to meet this need, educational institutions have undertaken different initiatives to integrate design for additive manufacturing (DfAM) into the engineering curriculum. However, limited research has explored the impact of these educational interventions in bringing about changes in the technical goodness of students' design outcomes, particularly through the integration of DfAM concepts in an engineering classroom environment. This study explores this gap using an experimental study with 193 participants recruited from a junior-level course on mechanical engineering design. The participants were split into three educational intervention groups: (1) no DfAM, (2) restrictive DfAM, and (3) restrictive and opportunistic (dual) DfAM. The effects of the educational intervention on the participants' use of DfAM were measured through changes in (1) participants' DfAM self-efficacy, (2) technical goodness of their AM design outcomes, and (3) participants' use of DfAM-related concepts when describing and evaluating their AM designs. The results showed that while all three educational interventions result in similar changes in the participants' opportunistic DfAM self-efficacy, participants who receive only restrictive DfAM inputs show the greatest increase in their restrictive DfAM self-efficacy. Further, we see that despite these differences, all three groups show a similar decrease in the technical goodness of their AM designs, after attending the lectures. A content analysis of the participants' design descriptions and evaluations revealed a simplification of their design geometries, which provides a possible explanation for the decrease in their technical goodness, despite the encouragement to utilize the design freedom of AM to improve functionality or optimize the weight of the structure. These results emphasize the need for more in-depth DfAM education to encourage the use of both opportunistic and restrictive DfAM during student design challenges. The results also highlight the possible influence of how the design problem is stated on the use of DfAM in solving it.

Additive manufacturing (AM) is widely used in various industries and has transformed the way products are designed and manufactured.Training workshops in conjunction with a part assessment framework encourage designers to use design for additive manufacturing (DfAM) considerations during the process of idea generation.In this respect, a training framework will assist researchers, educators, and students to evaluate and improve designs and encourage exploration of changes that need to be made during the design process.Successful implementation of DfAM considerations in engineering design classes are an important step in preparing students for professional careers.This research investigates the effect of DfAM integration in engineering curriculum on student design in the first-year engineering classes.Students are given a pre-intervention survey to gather information on their self-efficacy and prior experience with AM.Students complete a design challenge prior to the DfAM educational intervention that is then offered in the form of a design workshop in conjunction with a brief lecture.Ideas generated are collected and assessed using an assessment framework that encourages the use of DfAM considerations.Parts are scored on a scale of 1 to 4 in the following categories: part complexity, assembly complexity, number of separate parts, functionality, thin/smallest feature size, smallest tolerance, unsupported features, support material removal and the largest build plate contact.A score is generated and assigned to each design pre and post intervention.A post intervention survey is given to participants to gather information on changes in DfAM self-efficacy after the intervention as well as to gather feedback on suggested improvements and usefulness of the intervention workshops.The student outcomes before and after intervention are collected and compared for improvement in use of DfAM concepts.Gender differences are also investigated.Results show that DfAM educational intervention improves design scores and student DfAM self-efficacy.These results will enable educators to incorporate DfAM workshops in the engineering curriculum.

Design for manufacture and assembly (DfMA) in the architectural, engineering, and construction (AEC) industry is attracting the attention of designers, practitioners, and construction project stakeholders. Digital fabrication (Dfab) and design for additive manufacturing (DfAM) practices are found in current need of further research and development. The DfMA’s conceptual function is to maximize the process efficiency of Dfab and AM building projects. This work reviewed 171 relevant research articles over the past few decades. The concepts and the fundamentals of DfMA in building and construction were explored. In addition, DfMA procedures for Dfab, DfAM, and AM assembly processes were discussed. Lastly, the current machine learning research on DfMA in construction was also highlighted. As Dfab and DFAM are innovated, practical DFMA techniques begin to develop to a great extent. Large research gaps in the DfMA for Dfab and DfAM can be filled in terms of integrating them with product structural performance, management, studied cases, building information modeling (BIM), and machine learning to increase operational efficiency and sustainable practices.

An examination of designer and user perceptions of JAD and the traditional IS design methodology

Design for additive manufacturing (DfAM) creates opportunities for improved product design. Part consolidation (PC) is an important design opportunity in DfAM. The existing methodologies for part consolidation in DfAM are mostly based on expert judgment or heuristic rules. In addition, they only suggest the candidates for part consolidation. They do not assess the manufacturability of the consolidated parts. This paper proposes a two-level approach for part consolidation using complexity measures at the system level and part level. At the system level, the centrality score (a complex network measure) is used to identify parts with high potential for consolidation, and at the part level, a geometry-based complexity measure—modified complexity factor (MCF)—is used to assess the manufacturability. This two-step approach is expected to improve efficiency and effectiveness in DfAM since it uses minimal information at the system level and detailed assessment of manufacturability is done only for those parts where AM potential is high. Such an approach can be extremely useful to product designers at the early stages of design. Two case studies are presented to illustrate the effectiveness of the proposed approach.

Additive Manufacturing (AM) brought new design freedom and possibilities that enable design and manufacturing of products with new forms and functionalities. To utilise these possibilities a new design approach emerged, Design for Additive Manufacturing (DfAM), that contains methods and tools for supporting AM oriented design process. Designers working with AM are aware of the need to apply DfAM and AM possibilities in conceptual design phase where they have the most significant influence on product architecture and form but are facing a lack of suitable DfAM approaches for early design phases. Therefore, the presented research is investigating possibilities of storing and representing AM knowledge in the form of design principles to be used in the conceptual design phase. The paper proposes conceiving of Design Principles for Additive Manufacturing repository where formalised AM knowledge is stored in the form of design principles and structured based on function criteria. In the paper, various elements of design principle representation are discussed, as well as their role in the conceptual design process.

Design for Additive Manufacturing (DfAM) is a growing field of enquiry. Over the past few years, the scientific community has begun to explore this topic to provide a basis for supporting professional design practice. However, current knowledge is still largely fragmented, difficult to access and inconsistent in language and presentation. This paper seeks to collate and organise this dispersed but growing body of knowledge, using a single and coherent conceptual framework. The framework is based on a generic design process model and consists of five parts: Conceptual design, Embodiment design, Detail design and Process planning and Process selection. 81 articles on DfAM are mapped onto the framework to provide, for the first time, a clear summary of the state of the art across the whole design process. Nine directions for the future of DfAM research are then proposed.

The emerging additive manufacturing (AM) technology works in a layer-wise fashion which makes it possible to manipulate material distribution and composition. The resulting effects are reflected on the potential of innovative shape design, consolidated assembly, optimized topology, and functionally graded material. These new characteristics force designers to rethink about how to make a better engineering design. However, existing design theory and methodology cannot take these potentials provided by AM into account. To fill this void, various design for additive manufacturing (DFAM) approaches are reported. Unfortunately, majority of them focused on part-level redesign without potential of being extended to assembly-level applications. In order to shed a light into this emerging field, an overview of current assembly-level DFAM is summarized in this paper. After that, existing issues including the absent analysis of AM’s impact on conceptual design, the lack of explicit functional analysis method, the shortage of decision-making support for part consolidation, the deficiency of functional reasoning approaches to generate AM-enabled features, and the scarcity of integrating manufacturing and assembly knowledge into design stage are analyzed and discussed. However, it seems that addressing these issues is such a large scope that collaborative efforts are in need from both design and manufacturing communities. Therefore, this paper serves as a call to action for the research community to establish a comprehensive assembly-level/ product-level DFAM method to realize product evolution. As an initial benchmark, authors propose a three-stage design methodology on the basis of the Systematic Design approach. In the presented framework, functional analysis, part consolidation, and structural optimization with process knowledge integration are much highlighted. Moreover, a simple redesign case study is exemplified to clarify existing issues and how the benchmark method works. In the end, this paper is wrapped up with future research.

Additive manufacturing (AM) processes fabricate parts in a layer-by-layer manner by which materials are added and processed repeatedly. This article introduces the general concepts and approaches to design for AM (DFAM) and outlines important implications for part characteristics, design opportunities, manufacturing practices, supply chains, and even business models. It presents contrasting perspectives on DFAM, followed by a discussion on more general and overarching opportunistic design methods and on design for constraints, similar to conventional DFM. It concludes with a presentation of a design approach to the AM process chain, acknowledging that AM-fabricated parts typically undergo several postprocessing steps and that it is important to design taking into account these steps.

A Design for Additive Manufacturing Framework: Product Function Integration and Structure Simplification

Considering Part Orientation in Design for Additive Manufacturing

With the broader industrial application of Additive Manufacturing (AM), designers are facing new challenges in conceptual design for AM. To better understand the problematic, the authors organised a design workshop with six experts in AM. The paper presents the results of the conducted design workshop and discusses the current and future trends in research on the conceptual design for AM.

A RFBSE model for capturing engineers’ useful knowledge and experience during the design process

As Industry 4.0 is the driving force behind the manufacturing industry in this period, increasing importance is being attached to its enabling technologies, formerly known as the nine pillars. In particular, within this context, interest in Additive Manufacturing – AM is constantly growing. For this reason, the authors have considered as appropriate to carry out a literature search to assess whether there is any relationship between AM processes and product design and development practices after 2011. Particularly, the authors were interested in considering the use of additive technologies in relation to the TRIZ – theory of inventive problem solving - and its tools. To this end, it has been decided to carry out a search among the publications contained in the Scopus Database. 115 potential papers have been identified for analysis. After a careful selection, 14 papers, containing information on AM and TRIZ useful for our survey, were selected. Reading these works, it was possible to identify current research trends related to the use of creative problem solving strategies such as TRIZ and its combined use with AM, ranging from the definition of particular integrated methodologies of product development to the definition of guidelines for Design for AM or technological predictions, the state of the art of current research, highlights possible levers of intervention and potential developments and future trends.

Though design for building performance is traditionally considered an evaluative act, current developments in the theory and technology of digital design are promoting new directions for performance-based models of design. This paper presents a theoretical basis for understanding the current shift in performance-based design and proposes a model of performance-based design in architecture, termed performative design. Automated processes related to the impact of environmental forces on form generation in digital design are the content of experimental processes upon which the paper reports. In the theoretical introduction the terms performative design and performative architecture are defined and discussed. Topics related to the current movement towards performance-based design in architecture, such as the role of topology, parametric design, associative geometry, and generative processes, are presented, and their implications for, and influence upon, performative design are discussed. An experimental design example in architectural design is demonstrated to illustrate various methodological issues in performative design.