Additive Manufacturing (AM), also known as 3D printing, is unlocking the limitations of modern manufacturing. However, in order to fully realize the potential of Additive Manufacturing, new design tools are needed. For starters, let’s take a look at how Generative Design tools unlock the design limitations of CAD.
Generative Design is algorithm driven and various algorithms can be used. For example, engineering-driven Generative Design is based on physics (Finite Element Analysis and Topology Optimization), while industrial design is mostly heuristics and aesthetics-driven (for example, Voronoi diagrams).
ParaMatters’ functional Generative Design technology is focused on demanding engineering applications. In other words, the focus is on autonomous design of parts subjected to fatigue, vibration, thermal and other loading conditions. Typically, the target of such a design problem is to minimize weight while maintaining parts functionality and the ability to carry an applied set of loading conditions.
How Generative Design Works
So how does Generative Design work?
First, the user creates their 3D design in Onshape, determines design space, non-design features, material properties and loading conditions, and defines their design goals.
The rest is done by the ParaMatters Generative Design engine, called “CogniCAD.” Under the hood, the engine discretizes the design space (B-rep) and construct Finite Element model (which is volumetric). Then the optimization process iteratively redistributes material between elements, based on Finite Element Analysis results, until its convergence. The optimization result in Finite Element representation (volumetric domain) is converted back to surface representation (STL and STEP). The conversion back to surface representation is done in order to obtain design, which is compliant with 3D printing machines and traditional CAD systems.
These processes run fully automatically and no manual interaction is required. The final design is optimal in terms of satisfying engineering requirements, creating a smooth and watertight model ready for manufacturing or editing in CAD.
Generative Design is different from the traditional design process, as there is no need for direct manual modeling. The design is fully load driven, meaning that if loading conditions change, the design would change as well.
The Onshape-CogniCAD Workflow
Let’s take a look at the workflow between Onshape and CogniCAD:
Step 1. Sketch available design domain using Onshape. The design domain should be as large as possible without overlapping with other parts of the assembly:
Step 2. Non-design features should be added. These features will be preserved untouched by the Generative Design process and the assembly is imported into CogniCAD. User friendly and intuitive UI takes 6 steps to define the Generative Design process, which includes:
- Material properties
- Design and non-design volumes
- Loading conditions (forces, moments, pressure, acceleration, thermal and vibrations). If case loading conditions are not known, CogniCAD AI will suggest the appropriate loading conditions to generate a robust design based on an industrial application.
- Design goals (mass minimization under stress and stiffness constraints or stiffness maximization under mass constraints, etc).
Step 3. CogniCAD generates design which is organic, smooth and watertight. The design lays within the boundaries of the design space. The design is also backed by Finite Elements results: deformations and stresses.
The designs are available as STL file (mesh) and STEP (B-rep), which can be brought back to assembly in Onshape.
CogniCAD also optimizes and suggests on the build orientation, as a preparation to the design of support structures toward Additive Manufacturing.
In summary, ParaMatters Generative Design is a very powerful technology allowing the automatic generation of optimal and high-performance structures. It is nearly impossible to generate such optimal and complex designs using traditional tools and human intuition.
ParaMatters technology significantly shortens the design cycle, reduces manufacturing costs and improves design quality. The combination of traditional CAD tools and Generative Design will reshape the future of manufacturing.