Additive Manufacturing (AM) is a hot topic in the engineering, manufacturing, and product development worlds right now. People are excited about it for many reasons, and there is no doubt that it will be disruptive to the way products are ordered, designed, produced, and distributed. So if you’re beginning to implement, or even just consider AM, what will this mean to your PLM strategy? Will AM just create more files to manage, like the STL file format used to “3D print” the part? Or is there more information that needs to be managed along with a corresponding change in processes? What is the impact to the digital thread? Do we redefine Design for Manufacturing (DFM) because AM “design-driven manufacturing” is breaking so many of the past rules of manufacturing?
The short answer to the questions above is that AM will drastically change how product development is done, and therefore will have a very significant impact on PLM, PLM systems and the field of DFM. Three examples highlight the significant changes that are coming.
At a recent event, Dr. Laurence Vigeant-Langlois, Executive Marketing Leader for GE Additive, described a part-consolidation scenario where a subassembly consisting of more than one thousand components was redesigned as a single additive manufactured part. Imagine the cost and time savings realized simply through not having to assemble the design. And then consider the cost savings from not having to make each of the individual components. Keep going, and consider all of the possible design and supply partners who may have participated in the design and manufacturing of those legacy components. The fact is, this one scenario may have disrupted an entire supply chain of tens or hundreds of companies, along with the corresponding logistics and financial networks that supported them. Just as PLM systems are maturing in how they support extended design chain and supply chain networks, manufacturing may be shifting away from these complex networks as part counts are slashed through AM innovations.
In the last one hundred years or so, engineers have increased their value to product development organizations by collecting and leveraging manufacturing experience. DFM is such a significant piece of product development today that many junior engineers must work under the guidance of more experienced engineers and manufacturing experts before they can successfully contribute to product designs. But are the DFM “graybeards” who understand the nuance of traditional manufacturing processes actually at a disadvantage when designing parts for AM? Today’s engineers well-versed in traditional subtractive manufacturing wouldn’t even consider putting a lofted hole internal to a part—it is impossible to make. But a novice engineer might do that very thing, and in the process, create a single part design that fulfills the same function as a complex assembly created by their more experienced counterpart. The point is that many experienced engineers will need to “unlearn” or suspend what they know about designing for subtractive manufacturing to be effective at designing for additive manufacturing. AM introduces an entirely new body of knowledge to DFM. Will it disrupt the balance of power between new and experienced engineers and designers in the process?
The third example is the real mind-bender. AM presents a new and unexpected aspect of the digital thread: process definition will become more integral to the definition of a component. Prevailing wisdom in engineering has been that design engineers specify the product, not the process through which the product is made. This creates a nice hand-off between engineering and manufacturing that gives businesses the flexibility to change processes over time, between different facilities, and across geographies to minimize cost and maximize profit. Allowing design engineers to dictate the process can unfairly constrain manufacturing and keep product costs artificially high.
With AM, design engineers need to specify the process in addition to the product. Consider metal AM for a moment and the number of material properties that AM process parameters like laser power, dwell time, path orientation, etc. can impact: grain boundary size, crystalline structure, and isotropy, just to name a few. To get the desired performance characteristics of a part, parameters need to be optimized while planning the manufacture of the part. The logical byproduct of optimizing parts via AM process planning means that two parts made from the same metal chemistry will not necessarily have the same material properties if two different processes (or adjustments) were used to make them. This isn’t entirely foreign to traditional manufacturing because of processes like heat treating, annealing, etc., nor is it new to composites manufacturers (ply orientation makes a huge difference). But take a moment to consider the implications of this concept when it can be easily applied to every unique part design.
The performance of a part (when it will break, how it will deform, etc.) cannot be determined through the combination of part geometry and raw material composition alone. The process will be just as important to the performance as the geometry and the raw material. Throw out the Material Handbook; part performance can no longer be predicted solely by the tensile strength, yield strength, and fracture toughness for one of the hundreds of thousands of standard metals cataloged to date. The material performance options available to design engineers just went exponential.
If part performance can’t be predicted by combining geometry and generalized material properties in a finite element model, simulation and analysis tools will need to be rewritten (and the major players are already starting to make inroads on this). Today’s reverse engineering technology has very little value if it provides insufficient information (just geometry and raw material chemistry) to manufacture a similar part. What all of this points out is that capturing AM process data (planned and actual) will become a critical part of the digital thread that most people have not even considered yet.
Most businesses are ready to embrace AM and the significant benefits to cost, delivery time, and product complexity. But few businesses are ready to manage the data required to go along with these benefits. This is where an integrated PLM strategy can make a big difference: storing AM knowledge — and making it visible, transferable, and repeatable in manufacturing.
Jonathan Scott is Chief Architect at Razorleaf.
Filed Under: 3D printing • additive • stereolithography, Industrial automation