David W. Rosen

Additive manufacturing technologies : 3D printing, rapid prototyping, and direct digital manufacturing

This book covers in detail the various aspects of joining materials to form parts. A conceptual overview of rapid prototyping and layered manufacturing is given, beginning with the fundamentals so that readers can get up to speed quickly. Unusual and emerging applications such as micro-scale manufacturing, medical applications, aerospace, and rapid manufacturing are also discussed. This book provides a comprehensive overview of rapid prototyping technologies as well as support technologies such as software systems, vacuum casting, investment casting, plating, infiltration and other systems. This book also: Reflects recent developments and trends and adheres to the ASTM, SI, and other standards Includes chapters on automotive technology, aerospace technology and low-cost AM technologies Provides a broad range of technical questions to ensure comprehensive understanding of the concepts covered.

Computer-Aided Design for Additive Manufacturing of Cellular Structures

AbstractAdditive Manufacturing (AM) technologies, informally called “rapid prototyping,” enable the fabrication of parts and devices that are geometrically complex, have graded material compositions, and can be customized. In this paper, we focus on cellular materials and structures, which can lead to designs that are very geometrically complex. In order to take advantage of AM capabilities, new design and CAD methods must be developed. Two advances are reported in this paper. First, a new Design for Additive Manufacturing (DFAM) method is proposed that supports part and specification modeling, process planning, and manufacturing simulations. The method is based on the process-structure-property-behavior model that is common in the materials design literature. Second, Manufacturable ELements (MELs) are proposed as an intermediate representation for supporting the manufacturing related aspects of the method. These MELs represent process planning information for discrete geometric regions of a part and also...

Towards a Cloud-Based Design and Manufacturing Paradigm: Looking Backward, Looking Forward

The rise of cloud computing is radically changing the way enterprises manage their information technology (IT) assets. Considering the benefits of cloud computing to the information technology sector, we present a review of current research initiatives and applications of the cloud computing paradigm related to product design and manufacturing. In particular, we focus on exploring the potential of utilizing cloud computing for selected aspects of collaborative design, distributed manufacturing, collective innovation, data mining, semantic web technology, and virtualization. In addition, we propose to expand the paradigm of cloud computing to the field of computer-aided design and manufacturing and propose a new concept of cloud-based design and manufacturing (CBDM). Specifically, we (1) propose a comprehensive definition of CBDM; (2) discuss its key characteristics; (3) relate current research in design and manufacture to CBDM; and (4) identify key research issues and future trends.© 2012 ASME

Enhancing the Product Realization Process With Cloud-Based Design and Manufacturing Systems

The rise of cloud computing is radically changing the way enterprises manage their information technology assets. Considering the benefits of cloud computing to the information technology sector, we present a review of current research initiatives and applications of the cloud computing paradigm related to product design and manufacturing. In particular, we focus on exploring the potential of utilizing cloud computing for selected aspects of collaborative design, distributed manufacturing, collective innovation, data mining, semantic web technology, and virtualization. In addition, we propose to expand the paradigm of cloud computing to the field of computer-aided design (CAD) and manufacturing and propose a new concept of cloud-based design and manufacturing (CBDM). Specifically, we (1) propose a comprehensive definition of CBDM; (2) discuss its key characteristics; (3) relate current research in design and manufacture to CBDM; and (4) identify key research issues and future trends.

Layered manufacturing: current status and future trends

This paper reviews the emerging field of layered manufacturing. This field is little over 10 years old but a significant amount of research has been conducted and results to date are quite promising. We consider three broad topics namely, design systems for heterogeneous objects, layered manufacturing processes, and process planning techniques. Several applications/examples are included in the course of the survey and limitations of current technology identified. We conclude with some possibilities for the future. @DOI: 10.1115/1.1355029#

A process planning method for improving build performance in stereolithography

A process planning method is presented to aid stereolithography users in selecting appropriate values of process variables in order to achieve characteristics desired in a part to be fabricated. To accomplish this, the method achieves a balance of objectives specified by geometric tolerances, surface finishes, and part build time, where the balance is specified through preferences on the objectives. Given these objectives and preferences, values are chosen for six process variables to best achieve the balance of objectives. The process variables include part orientation, layer thicknesses, and four recoat variables (Z-level wait time, sweep period, hatch overcure, and fill overcure). The process planning method is adapted from multiobjective optimization and utilizes empirical data, analytical models, and heuristics to quantitatively relate process variables to the objectives. Of particular importance, a new adaptive slicing algorithm has been developed. The process planning method is demonstrated on a part with non-trivial geometric features.

Metrics for Assessing Design Freedom and Information Certainty in the Early Stages of Design

Our primary focus in this paper is on open engineering systems which are readily adaptable to changing design requirements. Designing an open engineering system allows a family of products to be developed around a common baseline model. This entails increasing design freedom and design knowledge during the early stages of design. Toward this end, developing ranged sets (as opposed to points sets) of top-level design specifications provides a means to improve system flexibility by increasing design knowledge while maintaining design freedom. Consequently, our secondary focus in this paper is on metrics for assessing the design freedom and information certainty associated with a ranged set of top-level design specifications. As a demonstration, these metrics are applied to an example problem, namely, the conceptual design of a family of aircraft. Our emphasis in this paper is on introducing open engineering systems and metrics for design freedom and information certainty, not on our example, per se.

Building around inserts: methods for fabricating complex devices in stereolithography

Stereolithography apparatus (SLA) is capable of in situ fabrication of complex parts, as well as mechanisms and complex devices with embedded components. In this paper, a series of example devices are presented to illustrate the power of building around embedded components (inserts). The problem formulation, solution approach, and specific rules and procedures are presented using these examples and experimental results. A case study approach is used for presentation. These procedures and results lend insight into promising new applications of SLA technology, as well as novel methods of implementing additional functionality into SLA and other rapid prototyping technologies.

An Inductive Design Exploration Method for Robust Multiscale Materials Design

Synthesis of hierarchical materials and products is an emerging systems design paradigm, which includes multiscale (quantum to continuum level) material simulation and product analysis models, uncertainty in the models, and the propagation of this uncertainty through the model chain. In order to support integrated multiscale materials and product design under uncertainty, we propose an inductive design exploration method (IDEM) in this paper. In IDEM, feasible ranged sets of specifications are found in a step-by-step, top-down (inductive) manner. In this method, a designer identifies feasible ranges for the interconnecting variables between the final two models in a model chain. Once feasible ranges of interconnecting variables between these two models are found, then, using this information, feasible ranges of interconnecting variables between the next to the last model and the model immediately preceding it are found. This process is continued until feasible ranged values for the input variables for the first model in the model chain are found. In IDEM, ranged sets of design specifications, instead of an optimal point solution, are identified for each segment of a multilevel design process. Hence, computer intensive calculations can be easily parallelized since the process of uncertainty analysis is decoupled from the design exploration process in IDEM. The method is demonstrated with the example of designing multifunctional energetic structural materials based on a chain of microscale and continuum level simulation models.

On combinatorial design spaces for the configuration design of product families

For typical optimization problems, the design space of interest is well defined: It is a subset of Rn, where n is the number of (continuous) variables. Constraints are often introduced to eliminate infeasible regions of this space from consideration. Many engineering design problems can be formulated as search in such a design space. For configuration design problems, however, the design space is much more difficult to define precisely, particularly when constraints are present. Configuration design spaces are discrete and combinatorial in nature, but not necessarily purely combinatorial, as certain combinations represent infeasible designs. One of our primary design objectives is to drastically reduce the effort to explore large combinatorial design spaces. We believe it is imperative to develop methods for mathematically defining design spaces for configuration design. The purpose of this paper is to outline our approach to defining configuration design spaces for engineering design, with an emphasis on the mathematics of the spaces and their combinations into larger spaces that more completely capture design requirements. Specifically, we introduce design spaces that model physical connectivity, functionality, and assemblability considerations for a representative product family, a class of coffeemakers. Then, we show how these spaces can be combined into a “common” product variety design space. We demonstrate how constraints can be defined and applied to these spaces so that feasible design regions can be directly modeled. Additionally, we explore the topological and combinatorial properties of these spaces. The application of this design space modeling methodology is illustrated using the coffeemaker product family.