Additive manufacturing, as now well known, produces objects by adding material rather than subtracting or melting it. Objects are made by depositing metals or polymers layer by layer instead of obtaining them by forging, injection molding, casting, or chip removal.

In the initial stages of additive manufacturing, little importance was given to the design phase, using 3D models designed for traditional manufacturing and not specifically designed for additive manufacturing. The problem of this way of proceeding is however that of not exploiting the true potential of this technology: that is to create new geometries that with traditional methods would have been impossible to achieve, and/or too expensive and/or that would have taken too long.

When it comes to going beyond simple rapid prototyping to enter the field of additive manufacturing (i.e. the construction of final and definitive pieces), it is not advisable to think of using 3D models that have not been specifically designed for additive manufacturing from the very beginning. steps of their development.

For example, additive manufacturing makes it possible to create lighter objects with the same mechanical resistance. These objects are therefore perfect for applications where weight plays a fundamental role, such as in racing or aerospace. This is where topological optimization and other peculiarities of design for additive manufacturing come into play.

To summarize: Designers must, therefore, begin to really design in the additive.

Of course, designers need the right tools and above all skills to do this.

Designers, engineers, and designers must, therefore, know the guidelines for the design of parts made in Additive Manufacturing and have complete mastery of the software tools that allow modeling, structural, topological, and process analysis.

Today there are many hardware and software opportunities already on the market. However, what will really create value and diversification for companies will be the ability to know how to design and think about a product for additive manufacturing from the very beginning of its development cycle.

THE REAL CHALLENGE WILL BE CHANGING THE DESIGN METHODOLOGY

Additive Manufacturing allows great freedom in the design of the piece, indefinitely extending the range of geometries and complexity achievable, removing design and processing constraints, with a view to rapid prototyping or small series.

But the passage to an additive method is more a cultural passage than a technological one, in the sense that it is possible to reason in an additive perspective only by taking a complete mastery of simulation and optimization software. Software that has been on the market for some time, even if it is constantly evolving.

3D printing is therefore not the final solution but only part of the solution. The great benefits and advantages that can derive from 3D printing in terms of new products can only be achieved by focusing on additive oriented simulation and testing tools.

Summarizing what can really create value and diversification for a company will be the ability to design and “think in additives” right from the start of the product development cycle “.

To be able to fully exploit the overall potential of additive manufacturing, a radical rethinking of the methods and approach to design will be necessary. Simulation and topological optimization will prove to be the key concepts in order to fine-tune the new product development logic.

MORE FLEXIBILITY WITH 3D PRINTING

The availability of Additive Manufacturing (AM) offers those who design a new and much wider space for conception and realization.

Generally, additive technologies offer new possibilities for customization, for the increase/optimization of product performance, for multi-functionality, for the reduction of manufacturing and assembly times and costs.

Additive technologies, therefore, refer to situations and cases characterized by the complexity of the shape, the complexity of material, functional complexity, allowing new design strategies.

For example, we want to highlight:

  • Functionality optimization, such as mass minimization and topological and topographic optimization without constraints on shape;
  • The adoption of cellular structures, and therefore the local variation of density with reticular structures that are not necessarily regular, and not necessarily with homogeneous or constant material, to maximize the mechanical characteristics by minimizing the material used and the production time;
  • Local and well-defined deformability (compliance), which makes it possible to replace assemblies of several parts (typically kinematic chains) with single pieces that have precise and well-sized points of deformation and that offer, for example, the same functionality as a hinge made however in one piece; therefore without problems of play, wear, and assembly;
  • The possibility of creating logically unique components in a single physical piece, eliminating long and complex assemblies necessary for accessibility problems.


However, we must not forget that the enormous opportunity and advantages of AM lie in the design, not in the production. The availability of Additive Manufacturing (AM) offers, in fact, to those who design a new and much wider space for conception and realization and therefore poses fundamental questions:

  • Generally, additive technologies offer new possibilities for customization, for the increase/optimization of product performance, for multi-functionality, for the reduction of manufacturing and assembly times and costs.
  • Functionality optimization, such as mass minimization and topological and topographic optimization without constraints on shape;
  • The adoption of cellular structures, and therefore the local variation of density with reticular structures that are not necessarily regular, and not necessarily with homogeneous or constant material, to maximize the mechanical characteristics by minimizing the material used and the production time;
  • Local and well-defined deformability (compliance), which makes it possible to replace assemblies of several parts (typically kinematic chains) with single pieces that have precise and well-sized points of deformation and that offer, for example, the same functionality as a hinge made however in one piece; therefore without problems of play, wear and assembly;
  • The possibility of creating logically unique components in a single physical piece, eliminating long and complex assemblies necessary for accessibility problems.

Trying to summarize, we can say that the availability of a production process – which additively produces the object “globally”, instead of obtaining it by deformation or by subtraction of material, with major constraints on the geometry that can be obtained compared to that theoretically necessary – totally undermines the two assumptions that have always been, and still are, at the basis of the design process we are used to and continued use:

  • a unique and homogeneous material for physical and chemical characteristics with substantially uniform properties and performances for every single piece;
  • a limited shape/morphology dictated by the production method: by deformation and/or by chip removal.

With additive technologies, these limits disappear and it is, therefore, possible to think and design and produce pieces with decidedly “non-traditional” shapes with the material that changes physicochemical characteristics from point to point and therefore without problems with regard to complexity, external shape, and the internal structure.

To achieve these objectives, however, we must question the way of designing and the tools to be used, through a critical and radical re-examination of the method adopted so far. We can observe that all the various generations of CAD (Computer-Aided Design) tools help in the phase of objective documentation of the result not so much or not at all in the phase of creating the potential solution.

The simulation techniques, integrated with those of optimization, in particular topological, allow instead to overturn the process in a much more effective way because, starting from the definition of objectives and constraints, they generate shapes that optimize the shape with respect to the specified objectives and constraints imposed.

Therefore, the new design support systems (called “simulation-based”) propose optimal design solutions oriented to the objectives and respectful of the constraints. Not taking into consideration the strong constraints imposed by the limitations of traditional production systems, the resulting shapes are much “lighter” and very “organic”, normally not producible with traditional production systems.

Abbiamo, inoltre, una eccellente opportunità: trarre vantaggio dalla disponibilità di metodi e tecniche di ottimizzazione sviluppate da più di 20 anni, e finora relegate in applicazioni di nicchia, per l’ottimizzazione di soluzioni tecniche (forme) definite con i metodi tradizionali precedentemente descritti, in particolare i metodi e gli strumenti per l’Ottimizzazione Topologica.

The topological optimization methodology thus becomes the cornerstone of the new design method, bringing the simulation to the initial phase of the project by “suggesting” optimal shapes based on the set objectives and on the existing geometric constraints that are completely feasible with additive methodologies, without being subjected to a priori constraints of “machinable” forms according to traditional processes, but entirely feasible with additive methodologies.

This new design approach, centered on topological optimization tools, makes it possible to explore the entire space of possible solutions by playing on the variety of objectives and constraints regarding the shape and homogeneity of the material, with the non-marginal result of acquiring directly and easily the sensitivity of the individual constraints and constraints with respect to the project objectives.