When car manufacturer Daimler formed a joint company in 2011 with Bosch, the world’s leading automotive supplier, the synergy between the two companies was obvious.
The joint company, EM-motive GmbH, combines Daimler’s expertise in fuel cells and batteries with Bosch’s knowledge of the development and production of electric motors to design and manufacture electric traction motors for electric and hybrid vehicles.
Because the motors are designed to be modular, they can be adapted to fit a variety of vehicle classes and meet specifications for many different vehicles.
Since 2012, the company has manufactured more than 300,000 e-motors for client companies throughout Europe.
Even with this combined expertise, manufacturing a modular engine is complex and challenging. In addition to the main engineering constraints (cost, mounting space for the motor, cooling and inverter-specific properties), the customer-based requirements for each type of engine cover a wide breadth of individual physical domains:
-Thermodynamics: coolant flow rate and temperature, environmental temperatures, as well as winding and magnetic temperatures
-Structural mechanics: mounting space, torque, power, speed, tolerances to other parts and forces on bearings
-Electrical engineering: voltage, current, inverter-specific properties
-Efficiency and acoustics: airborne and structure-borne noise
To make the challenge even greater, all of the parameters to be optimized have to be considered simultaneously. Other factors must also be taken into account: noise, vibration and harshness (NVH); safety; and the cost of the engine.
The engineers at EM-motive realized that, in such an interactive environment, a “classic” component development system, where rigid specifications for each component are designed separately and then assembled, was no longer possible.
Instead, the company developed a design workflow that incorporated simulation throughout to account for the dynamic interactions between the components, as well as all the necessary parameters to determine optimal solutions and ensure design robustness. The parametric workflow to support sensitivity analysis, design optimization and design robustness evaluation includes ANSYS simulation software and other software tools, and was built and hosted in ANSYS optiSLang.
These workflows help EM-motive to develop electric motors within challenging time and cost requirements, as well as resolve customized design challenges, such as a late-stage customer requirement change for an engine design.
As an example, a customer requested that the maximum speed for a particular engine needed to be increased by 1,000 revolutions per minute (rpm). The centrifugal forces of the accelerated speed, however, would cause the rotor design to fail.
The engineers could increase the bridge thickness of the pockets for the magnets that are punched into the rotor lamination to withstand stress caused by the higher centrifugal forces. However, this would increase the flux leakage in the rotor itself, causing reduced torque and power.
An option to address this reduction is to increase the current in the windings (but only if higher current is available from the battery and electronics system).
This solution would intensify losses and reduce efficiency, and was not acceptable to the customer. It was therefore necessary to redesign the entire engine to comply with all requirements.
Fortunately, the EM-motive simulation workflow can be flexibly adapted to analyze the requirements for a specific engine, simulate all the dynamic interactions between the components, and present the customer with a solid understanding of the trade-offs for each design decision.
The workflow provides the foundation to determine the best compromise for often contradictory goals.

A workflow for digital exploration

During the procurement phase, using ANSYS optiSLang workflow connected to CAD and employing specialized electromagnetic–thermal software, the design engineers have the freedom to explore possible variations and their tolerances to fulfill customer requirements. They can then provide a fast answer so the customer will know if the requirements can be met with available motors or if new motor development is needed.
Through a set of iterative phases in which additional requirements are added, a new motor is designed and optimized using ANSYS simulation software in all the relevant physical domains. A shared interface with the ANSYS Simplorer systems simulator helps them analyze the influence of power electronics on the motor.
Because there is a bidirectional interface between ANSYS DesignModeler and the CAD system, engineers can create parameterized models of auxiliary geometries, such as the housing, and integrate them into the system design. The ANSYS tools allow the designers to use the results of one type of simulation as a boundary condition for another.
They can then use forces from an electromagnetic simulation with ANSYS Maxwell as initial data for a structural mechanical simulation with ANSYS Mechanical.Using the various ANSYS tools integrated through ANSYS Workbench makes it possible to create a completely coupled simulation of the electromagnetic, mechanical, thermodynamic and acoustic domains.
With these parametric workflows in place, all important physical domain sensitivity studies within the relevant design space, as well as tolerance determination, can be conducted.
The engineers can add further optimization loops, but because of the conflicting character of many discipline goals and constraints, and because of the need to quickly check the motor behavior on a systems-simulation level, reduced-order models (ROMs) must be extracted. Using the integrated equivalent circuit extraction (ECE) toolkit within ANSYS Maxwell or ANSYS optiSLang’s data-based ROM generation, the team can extract reduced models for an overall system simulation.

Systems modeling

These reduced-order models can be coupled in ANSYS Simplorer to create a complete system simulation. Again a parametric workflow is built within optiSLang and, optionally, other third-party models can be integrated, such as a transmission model or a complete vehicle model. At this point, the engineers might perform a system optimization loop to analyze the interactions between the components by varying parameters such as those for the controller.
Finally, to make the model interchangeable with additional engine components designed by outside parties, the designers use the industry-standard functional mock-up interface (FMI) to create models of the individual components, called functional mock-up units (FMUs). These FMUs are created with third-party software and can easily be exchanged while maintaining IP confidentiality: since they contain only standardized inputs and outputs, the product-specific know-how is only accessible to the manufacturer.Another advantage of FMUs is that they can be imported into all current software packages for system simulation and can describe, for example, the behavior of the e-machine as a single component in the simulation landscape of a customer or development partner.

Understanding the options

The final challenge is to present the optimized designs so that the customer can clearly understand the different design choices and their trade-offs. EM-motive developed a single radar diagram that transforms all performance indicators into dimensionless variables using the requirements as standardization values.
It includes all domains and their requirements, further highlighted with a colored pie chart in the background, to clearly represent the domains.
All points that are located outside of the 100 percent reference circle meet the design requirements.
Interactions between physical domains are also easily depicted in the diagram. If, for example, a design should be revised to improve acoustics, the mostly negative effects on efficiency are plainly shown.
The chart provides a comprehensive understanding of the strengths and weakness of each redesign and how it fulfills (or doesn’t fulfill) their unique requirements.
Engine design, like many complex processes today, requires a collaborative, systemic approach to be successful.
EM-motive’s systemic approach to engine design integrates the ANSYS parametric simulation environment and an innovative presentation method to ensure that their automotive manufacturing customers can develop the next generation of hybrid and electric vehicles within challenging time and cost constraints.
(Marc Brück, Senior Expert Simulation Technology, EM-motive GmbH, Hildesheim, Germany- This article was originally published on “Ansys Advantage”)

With its roots in Pro/Engineer and the founding of the parametric, history-based modelling industry, Creo has come a long way since the late 1980s. Over the intervening period, the system has grown in coverage and now encompasses design, engineering, simulation, manufacturing and much more. It has subsumed other technology along the way (CoCreate and its direct modelling capabilities spring to mind), and today, it’s a behemoth of a system. The company behind it, meanwhile, has similarly grown and spread its wings. So what’s coming up in Creo 5?
In terms of user interface, Creo has been pretty consistent over the last few releases, with the majority of changes focused on adding in more modern touches that users have come to expect from their software. Creo is incrementally being modernised, but in a manner that’s manageable for its long-standing and highly experienced user community: it now comes with a full-screen mode backed up by context-aware mini toolbars, box selection and geometry regions in sketching (as opposed to fully trimmed sketch geometry). Mini toolbars are also available across a much wider spread of the system’s modules and in both 2D and 3D environments.
Additional updates to core modelling tools include changes in the way that the system handles adding drafts to parts that also feature rounds. Rather than trying to wrangle the whole thing, the new operation works in the background, removing rounds. It then applies the draft to the required faces and reapplies the rounds.

On this point, it’s also worth noting how Creo has some very interesting options when adding draft to components; specifically, building in drafted faces around a centre or split line. Whereas other systems require you to split faces, Creo’s draft operation has options to use a mid-plane and handles all of those problematic face-splitting operations for you.
The last general update is the introduction of volume-based helical sweeps. While this works just like a standard sweep feature, the difference here is that rather than sweeping a simple planar profile around the path, in this instance you’re using a geometric lump. It’s a small, rather subtle difference between the two, but the resulting feature is very different and is required for many different purposes, since volume sweeps are particularly useful for cams for mechanisms and some more complex thread forms (think drill bits).

Freestyle, style & isdx

Now let’s dive into an area in which Creo has been strong for many years – the use of industrial design-focused tools for complex shape development.
When we say “complex shape”, we’re talking about traditional surface modelling, where curvature continuity is essential, form control is paramount and in more recent years, the use of subdivision surface modelling technology has emerged. Creo’s offerings in this area are split across two areas. The Style module (part of the Interactive Surface Design Extension or ISDX toolset) provides traditional surface modelling tools you’ll need, while the Freestyle module brings subdivision modelling tools to the game.
Updates to the Style model for this release are minimal; after all, this is a set of tools that has been developed for 20 years or so, and has already reached a certain level of maturity. That said, there’s always room for improvement or adding a little more intelligence. For example, when you build a G3 (curvature continuity) relationship between two faces, the system automatically handles upgrading the curves that also define the connecting edges of those faces to the same level of continuity. This is something that would have taken a fair bit of manual work to accomplish previously.

Now, when creating new curves, you have the ability to specify a symmetry option, in order to build lighter weight curves spanning a mirror plane. With this comes the option for mirroring curves directly inside Style.
On the Sub-D modelling front, the biggest update to Freestyle is the ability to switch to a box mode for editing heavier, more geometrically rich models. This will be familiar to those users who have used other Sub-D tools. It shades the control mesh, giving you a coarse, faceted representation, but what it gives up in resolution, is gives back in interactivity, with much snappier responses to edits and providing greater clarity over the topology of the control mesh.

Additive manufacturing

We’ve all seen how 3D CAD vendors have jumped all over the additive manufacturing industry, with a view to pushing new functionality in their software tools. In fact, I don’t think I’ve seen a major software system released in the last few months that hasn’t referenced topology optimisation in some form or another.
As you might expect, Creo 5 is no different in this regard. Where it differs, however, is how the process fits into both the existing design and engineering workflow and Creo’s data structure. While Creo 4 brought us the ability to define lattice structures in our parts, Creo 5 starts to introduce both a new topology optimisation engine and a way to do something useful with the resulting data.
First things first, the optimisation process: Creo’s tools are built on the VR&D solver, Genesis. You then step through the familiar process of defining your boundary conditions, keep-in areas, keep-outs and so on, as well as optimisation targets (for minimising mass or displacement or maximising stiffness) and load case (or multiple cases, if you have the higher end module).
These are all then used to generate a mesh-based form that solves those criteria. At this point, many topology optimisation tools top out, leaving users with no choice but to use this mesh as the “inspiration” for a reworked solid and surface model.
What Creo does differently here is to provide an operation called Geometry Reconstruction. This uses a patch network of Freestyle subdivision surfaces, which is laid over the mesh and snapped into place. There’s no manual remodeling or skinning the model. A simple click and it’s done. Depending on your resulting model, the freestyle model entity will be complex, but it does means that you can integrate it into subsequent operations, whether that’s adding more engineering features, machining stock for post-processing or something else.

It’s worth noting that this module is available in two flavours. First, the entry-level flavour (snappily entitled “Creo Topology Optimization Extension”) allows you to define both structural and modal analysis types as part of the optimisation process with symmetric, cyclic symmetric and extrusion and filling as manufacturing or form constraints. It also limits the number of load cases used to inform the optimisation process to three.
Second, the Extension Plus variant opens up the number of load cases you can define, allowing you to include thermal analysis as an optimisation consideration and giving you a much wider range of constraints such as stamping.
Another additive manufacturing-related update for this release is the introduction of technology from Materialise’s range of Build Processors, which specifically target metal-building machines. Essentially, this means that you can design, engineer and test your metal parts in Creo, then also within the system. You can start to explore how to manufacture a part on a machine from the likes of Arcam, EOS, Renishaw, SLM, HP and Concept Laser and lay out your build chambers, generate your supports, experiment with orientation and so on.

Integrated Cfd

Another brand-new area of functionality is the introduction of Computational Fluid Dynamics (CFD) tools directly inside Creo. While there’s been a series of add-on tools for CFD work for Creo for a while, this is the first time that PTC has released something official and listed in its price book. The technology it has used is the Simerics’ solver, which while not being one of the big names in CFD, still has a very loyal following.
In terms of the Creo implementation, the workflow is pretty standard. You begin by defining the type of study you want to perform, whether it’s of an internal environment (for example, pumps or cooling inside an electronics enclosure) or an external environment (aerodynamics, for example). You then define the types of physics you want to use.

From there, you start to define your CFD domain from your CAD model. If you’re running an external study, this will be pretty easy as you’ll have your model ready to go. If you’re running an internal flow study, then you need to generate your fluid volume. Here, having your CAD model inside a powerful modelling system comes in handy, as creating your fluid volume is pretty much a single button push, once you have your inlets and outlets capped off. Then it’s a case of defining boundary conditions, the inlet, outlet and fluid details, and running your study. You’ll find that the whole process is neatly integrated into the Creo interface, with all of your study requirements managed through the panel to the left-hand side of the UI. Your interaction with results, meanwhile, is just as you would expect.

Model-based definition

Like other technology vendors focused on the large-enterprise end of the 3D design spectrum, Creo has been gaining 3D GD&T (or PMI) tools for some time now.
Creo 4, for example, introduced a new module that guides the user through the standards-based application of annotations to a 3D model. Built in partnership with Sigemtrix, a specialist in this field, the module handles the process neatly and efficiently, allowing to you quickly generate data that conforms to your chosen standard and checking it is fully constrained.
Creo 5 extends this work, to allow you to add semantic queries into your model using the GD&T you’ve already defined. So when design changes occur, or you are driving your part in an automated fashion, then it’ll help rip through any GD&T that becomes disassociated with the originating or reference data.
This release also sees the start of work to automate the creation of drawing views from 3D PMI-enabled data. This first instance allows you to quickly print or PDF fixed, formalised “state views”. While you can’t currently arrange these on a set of drawing sheets, you can see where things are headed.

Creo Integrated Cam

It has been a while since PTC talked about Creo-integrated CAM code. As long-term Pro/Engineer-era users will know, PTC has always had CAM tools available and, over ten years ago, these were boosted with the company’s acquisition of NC Graphics. But with the release of Creo 5, this topic has reemerged as a talking point.

In short, there’s a new set of CAM tools available in this release, based on the ModuleWorks CAM engine, and addressing subtractive manufacturing machinery from common or garden 3-axis high-speed machining operations to 3+2 operations. (As yet, there’s no word on simultaneous 5-axis as yet).

Augmented Reality & Iot

The final subject we’re going to cover is PTC’s work on Augmented Reality (AR) and the Internet of Things (IoT).
This has advanced considerably since Creo 4; in that release, for example, the company introduced a set of tools that allowed the user to generate an AR dataset that might be shared with anyone, directly from the application.
In Creo 4, this converted your Creo model, allowed you to add in a ‘ThingMark’ that enabled the viewing app to ID the correct dataset (they are cloud-hosted), and gave it scale. While this was a subset of PTC’s Vuforia tools, it proved interesting and easy to use – particularly key for getting folks to try AR as a means for design review.
For Creo 5, this work has continued. In the first instance, the capability has changed so you don’t need the Thingmark for scale. Instead, the apps will use spatial tracking and an awareness of surrounding elements to work out how to display your model at the correct, defined scale.
In addition, you also have a greater set of controls over access to the data you create, such as password access control that helps to enforce who can view your AR data.
On the IoT front, Creo 4 saw a bunch of tools introduced that made it possible to link Creo models to IoT data stored in PTC’s Thingworx platform. Creo’s Product Insight Module, for example, allows users to connect to data from a physical product, whether that’s a live one-to-one link or one that uses aggregated data.
With further development for Creo 5, you can now build in sensors within your digital model that will match up with sensors in the physical realm and, importantly, use that integration within the simulation environment. So what does that mean?
In short, it means that you can not only move your digital model using data from the real world, but also use physical sensors to drive simulation studies. The potential for this is huge, but there are also a few additional tools that we’ve heard about that will make this even more powerful, in the coming months, so stay tuned around June.

In conclusion

A couple of years ago, you might have been forgiven for thinking that the leadership of PTC had all but given up on the core 3D CAD portion of its business. The IoT and service management world was seemingly where its real focus lay.
But it transpires that what the company has actually managed to do is to broaden its focus to the brave new world of the IoT, but in a manner that means that 3D design and the data it creates take centre-stage.
That strategy seems, in turn, to have had a dramatic knock-on effect on the development resources committed to Creo, as the last few releases of the package have been impressive.

Creo 5 doesn’t disappoint, either. The company is clearly serious about additive manufacturing and, considering its position in automotive (in particular, powertrain) and aerospace (particularly the defence end of the spectrum), as well as some of the other transportation industries, it’s no surprise.
What’s interesting is how PTC is addressing the whole workflow, from optimisation of form according to function, to allowing you to plan manufacturing inside your design tool, and then onto enabling the machining of optimised forms and post-processing work.
Then there’s the work PTC is doing on bringing digital design and engineering systems together with the physical world, allowing user to not only drive assembly dynamics, but also conduct simulation work using real-world capture data.
But consider the impact if you successfully link those two areas up. Imagine an assembly, for example, that is directly linked to variants already out there in the field, an assembly that can use real-world data to drive optimisation routines on key components, adjust those that are under-performing (or indeed, are over-engineered), simulate a new, better form and prepare it for manufacturing. When you think about it, that’s quite something isn’t it? (Al Dean)