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No CAD without CAE

If you want to create innovative, marketable products for tomorrow you need to be able to immerse yourself in your design variants and run through CAD-CAE loops again and again. For this, Altair Inspire™ offers a comprehensive simulation-driven development environment.


Even though there is a lot of discussion about service approaches in the context of Industry 4.0 scenarios, the development of innovative physical products is still at the top of the manufacturing industry’s agenda. The fact that creating new products is one of the most cognitively challenging activities that human beings can do has not changed. This is because it confronts us with the task of devising new solutions against a background of often unclear and contradictory manufacturing requirements.

For time and cost savings, simulation and calculation based on suitable modeling has become established in product development in order to largely dispense with physical prototypes for property assurance. Simulation is also used to support production and material-oriented design.

Choosing the most suitable manufacturing process is not easy because there are many to choose from — all with advantages and disadvantages. The most important technologies include casting, forging, milling, drilling, welding, soldering, and various additive manufacturing processes. Gear wheels, for example, can be manufactured equally well by forging, or different hobbing processes. However, these processes differ in the achievable accuracy, the surface quality, the necessary machining time, the required machines, and tools as well as their flexibility.

In casting, molds or models must first be produced in dropforging dies. As they are quite expensive, the processes are only suitable for larger quantities. 3D printing, however, is known for its enormous freedom of design, but post-processing is a considerable cost driver. Around 30 to 40 percent of the manufacturing costs must be calculated for the reworking of the parts, such as cleaning, removing support structures, or finishing surfaces.

 

Requirements for CAx tools

To capture such finesses in product development, the development environment must meet the highest demands. Although there is a number of powerful CAE tools for the evaluation of component properties and the effects of manufacturing processes on the work pieces, these are usually pure expert systems that only proven calculation engineers can handle efficiently. In addition, simulation and calculation are often not explicitly anchored in the development department of the manufacturing company and are only used sporadically. This is, for example in consultation with an external service provider on a case-by-case basis. The consequence, in the product development process, information gaps open up between design creation and functional validation.

In order to obtain meaningful feedback on a design proposal as quickly as possible, it is crucial to closely link functional validation with the design. After all, it is important for the engineer not to have to read page-long reports from an external CAE expert about a problem, but to arrive at a solution as quickly as possible. So, if a porous area has appeared in a design for a 3D printing process, it must be immediately apparent how closing patches will affect the design as a whole.

But be careful — the integrated CAD/CAE environments typically offered on the market often do not provide the necessary quality in the calculation results, because the implemented solvers only provide reliable results in a very limited range of applications. This means that the user has to resort to a (non-integrated) high-end CAE tool or to go to the next engineering service provider. Altair, however, takes a different approach and offers highly intuitive modeling tools with Altair Inspire. Inspire includes Altair’s deeply integrated market-leading solver technologies such as Altair AcuSolve™ (fluid dynamics), Altair MotionSolve™ (multi-body dynamics), Altair SimLab™ (multiphysics), Altair Radioss™ (nonlinear structural analysis), Altair HyperMesh™, and Altair OptiStruct™ (linear structural analysis).

In addition, the individual Inspire module functions access powerful pre and post-processors such as Altair HyperMesh™, Altair HyperLife™, and Altair HyperView™. In addition, technologies from the optimization environments of OptiStruct and Altair HyperStudy™ are also accessible through Inspire. With this comprehensive approach, Altair bridges the gaps in the product development process — both in terms of function-focused design optimization and in the selection of the best manufacturing method.

 

Which production process do I choose?

Each part has its own unique characteristics, especially when it comes to 3D printing. A little more support material in one place, a little less wall thickness in another — with Inspire, users can study each layer of the 3D printing process to see what the difference is and what actions are needed to be taken to achieve the best result. Unlike the virtual machine concepts of other system providers, whose first thought is whether a workpiece can be produced with a 3D printer at all, Inspire also ensures that a design is created that can be produced optimally using a layered construction process.
Of course, Inspire’s choices are not limited to 3D printing, but also include drilling, milling, cutting, casting, forming, and extrusion. It should also be mentioned that it is very easy to switch from one production process to another within the Inspire environment. Of course, the design will change, but the user can always be sure that the presented solution reflects the optimum.

 

Form follows function

The most suitable manufacturing process is, of course, only one aspect in the search for a solution that satisfies every stakeholder. Irrespective of this, it is important to find an unsurpassed geometry for the respective application. And computers and algorithms are often better at doing that than human beings. Topology or shape optimization is used to propose geometries in which the workpiece is as light as possible while at the same time offering the highest possible rigidity and durability. Non-loadbearing areas are removed by the algorithm with the help of the finite element method, stiffeners, ribs, and openings are added where they are really needed.

The topology optimization calculates a favorable basic shape for components under the given loads, which are then adapted to the given boundary conditions using additional tools. In shape optimization, the boundary (surface) is modified so that the maximum stress is reduced and homogenized.

The highlight of the topology optimization offered by Altair is that it not only takes into account loads and space constraints, but also the different manufacturing processes as described above. Thus, the optimization can be performed explicitly with regard to casting. Or to 3D printing. In this way, the individual processes can be weighed up using hard facts.

Inspire offers a range of topology options, including optimization targets, stress and displacement conditions, acceleration, gravity, and temperature conditions. In addition, the user can perform linear static and ordinary mode analysis on the same 3D model, visualize the influence of displacements, safety factors, elongation and compression and always have the resulting von Mises and principal stresses at a glance.

Inspire is equipped with a material library containing various aluminum, steel, magnesium, and titanium alloys. Tailor-made materials can also be added, and their effects studied. Material can be added or removed using sliders.
It is well known that a part doesn’t come on its own. Therefore, the technology provider offers the possibility to create several assembly variants. These configurations can be used to play through and evaluate different design scenarios and the resulting concepts.

This makes it possible to easily simulate dynamic movements of complex mechanisms, with contacts, joints, springs and dampers being automatically identified. The forces obtained from a motion analysis are used as input for a structural analysis and optimization or can be used to determine the start parameters of motors and actuators.

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Pictured left: Initial design of a mounting bracket from the aircraft industry. The goal is a lower weight with the same or higher stiffness.

 

Pictured middle: Shown is the initial design with defined installation space.

Pictured right: Here are the results of the subsequent calculation.

Pictured left: Optimized design with analysis.


Pictured middle: With PolyNurbs, a tool of the Altair Inspire suite, closed free-form surfaces can be created quickly. Here applied to the optimized and analyzed design.


Pictured right: The new design results are impressive. The so-called buy-to-fly ratio was reduced from 17 to 1.5. It expresses the ratio of the initial weight of the semi-finished product to the final weight of the finished component. A value of 1.5 means that only 50 percent of the original raw material is consumed in the production.

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The new design (front) compared to the original design

 

Conclusion

Anyone faced with the decision to invest massively in simulation and calculation should first consider that a deeply integrated CAE infrastructure should always be a central component of an Industry 4.0 approach. Altair’s Inspire development environment achieves this by providing not only superior modeling tools, but also market-leading solvers and best-practice solution strategies. And it does so for nearly every established manufacturing process. It’s no wonder that Inspire is valued by designers and business professionals alike: The former can give free rein to their creativity, while the latter enjoy cost reductions and time savings in the development departments. Both target groups are happy to be inspired by Inspire.

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