Additive manufacturing (AM) has disrupted industries such as aerospace, defense, biomedical, transportation, power generation, oil and gas exploration, chemical processing and electronics, among others. AM’s appeal, in part, comes from bypassing drawings and subcomponents creation steps and converting computer-aided design (CAD) directly into finished assemblies. It also reduces waste by using only the material required to fabricate the finished part.
Beyond rapid prototyping
Over the past decade, AM has experienced exponential growth as manufacturers use the approach as a legitimate vehicle for production manufacturing, not just for rapid prototyping.
With less emphasis on communicating key design features in a drawing, improving the CAD software engineers use to design the parts has been key to introducing AM to new industries. In turn, software companies are heavily investing in process simulation tools. These tools now include provisions for the internal support structure of the AM parts, helping to address the design of a primary manufacturing difference of this technology.
3D performance prediction software also is gaining support.
“Billions of dollars of investment have occurred in new machines, materials, start-ups, software and application development,” says Brent Stucker, director of additive manufacturing at engineering simulation company ANSYS. Finite element analysis (FEA) can predict part performance and durability under structural or thermal load, while computational fluid dynamics (CFD) models hydrodynamic performance and conjugate heat transfer in an internal volume. These numerical FEA and CFD programs, such as ANSYS Mechanical (FEA) and Fluent (CFD), have robust programmability and definition of boundary conditions, improving the accuracy of the prediction.
“A number of companies are heavily investing in developing and bringing to market simulation technologies that enable users to optimize part geometry, build parts accurately, avoid build failure and optimize process parameters and post-processing operations,” he says.
These predictive measures address quality concerns and lead to repeatable, qualified production at reduced costs and shorter time to market while positively affecting AM’s market growth.
Impact on product design
Because the fabrication method of parts is fundamentally different from traditional methods, AM design enables adoption by new industries and markets. Displacing a traditionally manufactured production part with an additively manufactured product is not always economical, because engineers already have optimized the process for the application.
“If a company is replacing a traditionally manufactured geometry with an additively manufactured geometry of the same design, there is typically little benefit in doing so,” Stucker says. The most significant opportunity to switch to additive manufacturing is during design or new part design.
Like castings, AM seamlessly incorporates complex geometries, transitions, and subcomponent integrations in one piece. However, the process does so without the high cost, lead time, or material thickness constraints of castings. Redesigning or creating a new part to leverage AM’s advantages creates a significant opportunity for the industry to adopt the technology. For example, a fluid manifold could incorporate intricate turns and transitions to manage pressure drop while optimizing flow distribution and performance as well as minimizing size. This same piece could incorporate mounting features without the necessary mass of castings, decreasing the structural load on the interface joint.
Additive manufacturing has grown from a smart, rapid prototype technology into a legitimate vehicle for expedient, efficient and cost-effective mass manufacturing. Engineers are learning how to modify the design process, and suppliers are developing innovative products to expand the market.
Using predictive tools to simulate process dynamics improves confidence in the additive manufacturing process. Engineers can reduce the amount of tooling and fixturing by eliminating or combining process steps, resulting in cost savings. The decrease in part count minimizes the labor cost associated with joining separate parts and reduces tolerance stack-up discrepancies by reducing the number of assembled parts.
Using innovative tools to design and optimize the parts for additive manufacturing can enable new industries to adopt the process, which is limited only by the imagination of the design engineer.