Inspire 2016 workflow. (All images courtesy of Altair solidThinking.)

Topology optimization is used early in the design cycle to determine a mathematically optimal shape for a given part in a limited space under a certain set of loads. Engineers define a packaging space the part will occupy and various loads and load types the part will experience.

The software then uses simulation technology to determine an optimized shape to handle the loads with minimal material, mass, or stress. These often organic looking results can then be brought into a CAD program to “finish” the shape, for documentation, to get it ready for fabrication or other downstream applications.

“Programs like Inspire perform these topology optimizations in an effort to cut down the development cycle,” said Jaideep Bangal senior application engineer at solidThinking. “After using Inspire, much of the design is already completed, engineers need only to put the finishing touches on the model.”

The release of Inspire 2016 is focused on how to get these optimized concept results to manufacturing quicker.

PolyNURBS Models Are Fleshed out Over Optimized Concept Designs

In past releases, design engineers would have to import the geometry back into CAD using an Inspire function that fits surfaces over the optimized geometry. However, using various new tools, engineers can now create a full PolyNURBS object.

New PolyNURBS tools in Inspire 2016 brings the concept designs into CAD as a solid geometry.

“The main advantage of PolyNURBS is the ability to bring it back into CAD as a solid geometry, or 3D Printer directly,” said Bangal. “Using the PolyNURBS wrap and other new functions, you can create a solid organic geometry from the optimization results very quickly compared to traditional CAD.”

The idea is to import a more polished geometry into your CAD system so that you only have to add the final detail to the geometry. The fine level of CAD control necessary for adding this detail isn’t possible in Inspire, but the closer the program can get to the targeted geometry, the faster the design can move down the development cycle.

The new PolyNURBS tools in this release include:

Create PolyNURBS: which produces a free-formed solid that is smooth and continuous
Wrap: which produces a smooth polyNURBS shape around your concept geometry
Add/Remove: which allows engineers to push and pull on a surface, extending the edge out with smooth transitions
Loop: which gives engineers the ability to split existing blocks allowing for more control when manipulating the geometry
Bridge: which connects two polyNURBS surfaces with a smooth transition
Sharpen: which squares off smooth transitions in the polyNURBS geometry to create designs that are easier to extrude and manufacture

This new release also includes some more traditional geometry tools such as midsurfacing, mirroring, scaling, revolve and a more traditional push-and-pull function. However, although these tools are used in CAD programs to build your shape, here they are used to maximize the packing shape for the optimization process.

“Inspire is not a CAD tool and it won’t overlap with existing CAD tools, explained Bangal. “These tools are used to make quick changes to the geometry and modify the design space and remove detail for the optimization. We don’t want to make another CAD package, we want Inspire to be used before CAD and between CAD and Simulation for concept generation.”

New Forces at Play in Concept Design Optimization

Buckling analysis performed in Inspire 2016.

The next category of enhancements to Inspire 2016 comes the in the form of new load options. These loads allow the user to test more optimization scenarios on their model, giving more insight early in the development cycle.

For instance, engineers can assess the g-loads their model may undergo while experiencing acceleration. “This new function is good for those in the automotive and aerospace industries,” said Bangal. “You can determine the optimal topology for a car part that is experiencing increased g-forces while the car is turning a tight corner.”

Other forms of rotational movement that can be assessed in the latest release are angular velocity and acceleration. Adding angular acceleration to your model will ensure that turbine, motor and rotating machinery will be optimized before moving onto the initial CAD stage. This should help to reduce the risk of turbines failing during prototyping and early simulations.

An interesting addition to solidThinking’s release is the new buckling analysis. To keep the calculation simple for the early design cycle, the engineer only needs to define the load cases and the number of modes to run the analysis.

“The results contain the buckling factors which are used to determine if the part will buckle or how much load in a given direction would be required to cause the part to buckle,” said Bangal.

All the above simulations are great, but sometimes an engineer is in the dark as to the forces their product will experience. All they have is some experimental data collected from an earlier design such as deflections.

In this situation, the engineer can now assign an enforced displacement as the applied load for their topology optimization. The software will then back-calculate the force based on the displacement, the material and the shape of the component. The program will then construct the optimized result based on that calculated force.

Unfortunately, all of the analysis techniques available in Inspire assume that the material has linear static properties. As many industries are moving to non-linear materials, like composites, this is an area many engineers will need to have addressed.

However, Bangal noted that “Inspire is used by design engineers at the beginning of the development cycle so you don’t want to get too complicated. You want quick turnarounds so you shouldn’t focus too heavily on the material properties. Estimations will work fine at this stage and then you can pass on the tougher analysis to the analysts to perform later in the development cycle.”

How to Compare Concept Designs Optimized to Various Loads?

Finally, engineers might be interested in using Inspire to compare various designs based on different load-type optimizations. Using the comparison tool, engineers will be able to look at a table that is directly linked to the results.

Comparison chart allows engineers to quickly assess various designs.

They can then interrogate the models using filters, points of interests, mass, manufacturing options and different results.

“It’s a great tool to find which load cases contribute to the highest stresses or displacements based on the analysis runs,” explained Bangal. “You can relate various analyses, optimizations, and load case options in the compare tool.”

To learn more about Inspire 2016 follow this link.

Altair solidThinking has sponsored this post. They have no editorial input to this post - all opinions are mine. Shawn Wasserman