Design automation for various design goals with PTC Creo Parametric Behavioral Modeling Extension (BMX)
Personally I believe that everyone who actively designs products for today’s highly competitive and optimized market knows the problem of determining the optimal combination of different dimensions and parameters. Of course, there is always the possibility of trial-and-error. In simple situations, this may still be applicable.
But at the latest, when it comes to combinations that are in the triple-digit decimal range, it will be difficult for us humans. With Behavioral Modeling Extension, Creo Parametric (formerly Pro/ENGINEER Wildfire) offers the ability to provide top-level tools exactly in these situations.
Let’s take a look at the functions of the PTC Creo Parametric Behavioral Modeling Extension (BMX) in a simple example:
Our job as a designer today is to design a bottle. This bottle should have 1 l capacity – or even a bit more. In addition, we would like level markings at 0.5 l and 1 l. Our bottle must not be higher than 200 millimeters and must not exceed 115 mm in diameter. The silhouette of our bottle was given to us by a designer and follows a non-regular or no cylindrical shape. This means that even a normal volume calculation would involve a considerable effort. Now, of course, a volume calculation is absolutely nothing special anymore.
In the screenshot below you can see that I have modelled the bottle and already prepared it with the volume of the liquid. The filling level of the bottle is controlled via the fill level.
First, we look at how changing a parameter affects the volume of the bottle. We can do this through a sensitivity study. To this end, we tell the tool that, on the one hand, it should measure the volume and on the other hand, which parameter should be analyzed. In our case, this is the measurement “volume” that we have placed as a feature in the model tree and the sketch dimension “d56:FLASCHE”. For “d56:FLASCHE” we now specify the range spanning from 100mm to 115mm and in how many segments the analysis should be carried out; we set that on 20.
The result is shown in the graph at the top right of the screenshot. Roughly above the thumb we see that the change of the parameter “d56:FLASCHE” by 3 millimeters leads to a change in volume by about 50 milliliters. The change is linear here; if we were to change an angle here, we could see a progressive or degressive change in volume.
Next, we’ll look at how to place the level marker at exactly 0.5 l. With a rule geometry, this would not be a problem, but here we would have to try a lot until the result would fit. With the Creo BMX, however, this is now a very, very small problem.
To do this, we first give the “Feasibility Study” tool which dimension it can change. In our example, this is only a single measure, of course you can use as many as you like here.
We use the measure “d7:BLOG_BMX”, which controls the offset of the level “fill level”; this also references the sketch that creates the level stroke. Next, we use the “volume” measurement from our sensitivity study. We stipulate here that our volume should be exactly 500,000 mm3. You can see in the screenshot what exactly I have specified.
After the study is connected, we see that the dimension “d7:BLOG_BMX” has been set to exactly 122.917 mm.
As you can see, it is very easy to actually create a perfect result for our level with the Creo Parametric – Behavioral Modelling Extension (BMX). For a simple bottle maybe a bit of overkill, but definitely an illustrative example.
But think more about the complex problems you can manage with this. As a brief extended example, I would like to show you an oil tank. This belongs to a snowmobile from Polaris. In the study here, there are 5 different design variables – including one angle and 2 design conditions – that we want to achieve.
The initial situation is a very limited construction space, which allows only little margin.
We would like to have our capacity larger than or equal to 3.71 l. At the same time, a filling line should be placed at 1.19 l. I think it is already clear that this task would either take a great deal of time for a human being or lead to a suboptimal result.
As complexity increases, we quickly move into areas that are no longer feasible for us humans.
Finally, I would like to present a small but quite helpful tool of the Behavioral Modelling Extension. The performance monitoring gives me the possibility to monitor one or more measured values in my design. If one of these values does not match the specified range, I will see it immediately and always visibly. As an example, we use the absolute height of our bottle.
I think every designer knows this: you construct like that and think, “Oh, that turned out well,” only to say, “Oops, I didn’t meet my two construction conditions.”
As I construct, I see the display of the power monitoring at the bottom right in the form of a pulse line. This is either green or red depending on the status.
Let’s summarize what we have learned. How can the PTC Creo Behavioral Modelling Extension (BMX) help your team?
- The ability to innovate more by simply experimenting with numerous scenarios that meet your design criteria
- Clear understanding of the impact of design changes and preventing inconsistent behavior in your designs
- Lower product costs by optimizing design for multiple goals, e.g. reducing product weight while maintaining strength
- Very high time savings due to automatic design iterations according to design requirements
- Lower error rate by directly integrating the results of external tools into the design work, without tedious manual data transfers
Why not try Creo Parametric Behavioral Modelling Extension (BMX) yourself and convince yourself of the advantages of PTC Creo Parametric (formerly Pro/ENGINEER Wildfire)? Don’t have a Creo Parametric yet? Just contact us or arrange a demo appointment with us. We will also be happy to show you our examples live and support you in optimizing your internal design process.
For more information, contact us here.
