Objective:
Understanding new optimization technology available in nTop 3.45 through our beta features (What are beta blocks?)
What is happening?
A new optimization framework is becoming available in beta in 3.45. This optimization framework is called “Field Optimization,” or FO for short. Built upon nTop's implicit modeling, field-driven design, latticing, and optimization capabilities, FO is a new generative design technology that allows complex geometries, such as lattices, to be optimized at every point.
For an overview of Field Optimization, including how it works, capabilities in nTop, and examples, you can watch the video below.
Frequently Answered Questions
1. Will any of my previous topology optimizations be impacted
No, field optimization is a new optimization process that will use many blocks from the existing topology optimization framework. No modifications to existing blocks have been made.
2. How do I get access to the field optimization blocks
The field optimization blocks will be available through Field Optimization under the beta tab
3. Where can I learn about field optimization and/or find example files?
Example files are available in the nTop documentation (Block Documentation -> Blocks -> Optimization), which can be easily accessed with the “Learn More” button in the Information tab of the Field Optimization block. Additionally, a support article for running field optimization can be found here.
4. How is field optimization different from topology optimization?
For Topology Optimization, nTop employs the popular SIMP (Solid Isotropic Material with Penalization) method by computing relative densities of elements in the design space that satisfy a set of objectives and constraints and then filtering those elements based on user input or heuristics. Rather than filtering a mesh based on its value to the optimization problem, Field Optimization uses a custom material model optimization algorithm allowing for many different design parameters (i.e., beam thickness) to be directly optimized.
5. How do I optimize a different design parameter?
The design variables are determined by the type of Parametric FE Component selected. The currently available Parametric FE Components are for Voronoi lattices, periodic lattices (beam and surface-based), variable shells, and shell+infill optimizations. Additional FE Components will become available in the future, as well as the ability to create custom ones.
6. What design responses and constraints are available for Field Optimization?
All design responses available for topology optimization can be used in field optimization. The geometric constraints which are not supported by field optimization are the Extrusion Constraint and the Overhang Constraint.
7. How do I refine my design if it doesn't look printable?
It is recommended to validate the bounds of your design parameters by toggling the visualizability icon of the Parametric FE Component block. The rendered view will be constructed with the initial parameters provided in the block inputs. Adjusting these bounds will help ensure your final model can meet manufacturing restrictions.
8. Can I use an existing lattice or shelled geometry as an input into field optimization?
Currently, the field optimization pipeline is limited to using the Parametric FE component blocks to generate and optimize your design.
9. What is the difference between a Parametric Lattice Component and an FE Lattice Component?
An FE Lattice Component is used with simulation analyses to mesh a lattice using beam or shell elements and prepare it for simulation. A Parametric Lattice Component is used in field optimization to set up and optimize a periodic lattice (graph or TPMS) for a given objective. The different components are not interchangeable.
10. Does field optimization use homogenization? If yes, how valid do you think the results are given the assumptions you make with homogenization?
Homogenization is one technique that correlates design parameters to the mechanical properties used for the field optimization process. However, additional methods/approaches may be used, as is the case with shell optimization. When using a data model which relies on homogenization (like the parametric lattice component), the accuracy will depend on mesh size, the data collected as well as how accurately the homogenization assumptions hold true for the given engineering problem.
11. If I use a stress constraint, does it resolve the stresses on the actual geometry? Or is it just using the stress of the background mesh as a proxy? What are the impacts of that behavior on the part? Can you actually claim the design satisfies my stress constraint?
The stress constraint does not resolve the stress on the actual geometry, Only the background mesh with the equivalent properties. For this reason, it is important to perform a post-optimization verification on the results to ensure any stress constraints have been met.