Abstract
Additive manufacturing (AM) has developed and gained popularity across the globe into a multi-billion-dollar industry that involves many materials and techniques. AM has created itself as a technology for the manufacturing of metallic parts with enhanced mechanical characteristics that are scientifically sound and commercially feasible. However, there are various challenges, from business point of view, like high machine and material costs. Considering the complexities involved, sustainable manufacturing, optimization tools, and simulation models are necessary in order to save time and costly trial and errors. Topology optimization and simulation of AM processes are commercially available and are receiving attention from scientists and industry. Thus, this chapter is designed to provide readers with a brief introduction to AM technologies with typical applications. The main objective of this chapter is to provide the current trends and innovations in the field of design for additive manufacturing (DFAM), topology optimization, and simulation technologies.
TopIntroduction
Additive manufacturing (AM) has developed and gained popularity across the globe into a multi-billion-dollar industry that involves many materials and techniques (Kalita et al., 2019). Thus, AM also known as Rapid Prototyping (RP), 3D printing or freeform manufacturing, is defined as the “process of joining materials to produce parts from 3D model data, usually layer by layer, as opposed to subtractive manufacturing and formative manufacturing methodologies” as per International Organization for Standardization (ISO)/American Society for Testing and Materials (ASTM) 52900:2015 standards (Lee et al., 2017). RP normally refers to technology and tools that enable the manufacture of physical objects from the solid models produced in Computer Aided Design (CAD) using techniques of additive layer manufacturing without manufacturing process planning, tooling or any type of fixtures (Chang, 2015; Herzog et al., 2016; Ngo et al., 2018).
Generic Additive Manufacturing Process
AM involves several steps, starting from a virtual CAD model to final physical component (Gibson et al., 2010). The general AM process, right from a CAD model to final manufacture of the part is illustrated in Figure 1.
Figure 1. General process of Additive Manufacturing from CAD to part
Step 1: Concept design: In general AM process starts with a 3D CAD model created in a computer software. Most of the 3D systems are solid model systems with some surface modelling features (Gibson et al., 2010).
Step 2: Conversion to STL: The term STL is known as Stereolithography. It functions by eliminating all structural data, modelling history and approximates the model surfaces to a number of triangular facets. Thus, STL is basically a surface description of the model.
Step 3: Transfer to 3D printer and operation. The STL file once created, is sent directly to the 3D printer or the AM machine.
Step 4: Setup of AM machine: Most of the AM machineries have some specific built-in parameters, with respect to a particular machine or process. Complex cases have default settings, so as to accelerate the AM machine process setup and to minimize mistakes.
Step 5: Build: The AM process stages are semi-automated and requires significant manual control and decision-making. AM machines requires a follow-up in the arrangement of layer control, material deposition, and cross-section formation, until the build-up model is produced.
Step 6: Removal of parts and cleaning: The product of the AM-machine should be ready for use. The parts are separated/ removed from extra material surrounding the part.
Step 7: Post-processing: It refers to the stages of finishing, polishing, sandpapering, or application of coatings on the parts
Step 8: Application: AM parts are ready to use for different industrial applications.
Key Terms in this Chapter
Additive Manufacturing: AM also known as Rapid Prototyping or 3D printing is defined as the process of joining materials to produce parts from 3D model data, usually layer by layer, as opposed to subtractive manufacturing and formative manufacturing methodologies as per ISO/ASTM standards.
Applications of Additive Manufacturing: The rapid prototyping has been widely used as a powerful tool for product creation in various industries. Major areas of AM applications include: Product design, manufacturing, tool and mold making, automotive, electronics, art, medical, bioengineering, etc.
Simulation: Simulation is conducting computer-based experiments with the model and predict the real behavior of the system. It is an effective tool in saving time and minimizing the costly trial and errors experiments. Simulation optimization is a process which finds the best input variable values among all the possibilities available.
Topology Optimization: TO is a type of optimization methods that vary in size and shape optimization. SIMP and BESO are broadly used TO algorithms.
DFAM: DFAM is design for manufacturability in context to AM. Some of the tools of DFAM include topology optimization.
Optimization: Optimization is a process or technique involved in a system, design, or decision making in order to make it fully functional, perfect or effective as much as possible. An optimization problem is a mathematical formulation wherein, design parameters or variables needs to be identified or determined to achieve the best measurable performance or objective function, by considering the given constraints.
Additive Simulation: Some of the 3D Printing Simulation software include ANSYS Additive suite, Autodesk’s Netfabb, Simufact Additive, etc.