Many studies on automotive mass reduction have been undertaken over the years by various steel, aluminum, magnesium, and composites consortia, all expounding the virtues of substituting a particular material. Altair has participated in studies with all these organizations over the years and has understood the strengths, limitations, and constraints of working with various materials.

AHSS, HSS, Al, Mg, Ti, GFRP, CFRP…
High Strength Steels, Aluminum, and Magnesium all have certain advantages in specific applications. Understanding when to exploit the unique advantages of these materials while concurrently minimizing the associated cost penalty is key in any weight reduction challenge.

Where energy mitigation is the driver, High Strength Steels (HSS) traditionally have an advantage but where strength and stiffness are dominant and durability is of less concern, significant weight save can be realized by using aluminum and magnesium. Depending on the part geometry, processing, and manufacturing constraints, one may yield a lower cost penalty and greater weight save.

Degradation of strength & fatigue properties due to welding, as well as issues related to joining dissimilar materials, such as expansivity mismatch and galvanic corrosion  are some issues that must be considered in the overall design. When the design freedom allows for expanding the package space to accommodate larger sections or when certain net-shape re-designs to consolidate features can be exploited, composites can have a significant advantage.

Understanding Dominant Loading Characteristics
Except for idealized theoretical models, most real world structures see a multitude of loads making selection of the optimal material usage difficult without the right toolset, and materials and manufacturing knowledge. Front crash rails are predominantly loaded in the axial direction requiring the capacity to accommodate high plastic strains while side impact structures are loaded mostly bending requiring high yield strength.

The passenger compartment and green-house structure must minimize intrusion and provide adequate stiffness to meet NVH requirements.

When designing with different materials, the existence of varying dominant loads in different regions of the vehicle structure must be exploited. The use of Topology Optimization early in the design development phase can help distinguish regions that are stiffness dominant and those that are strength dominant. Regions that are strength dominant benefit the most from using high specific strength materials.

Steel body in white (BIW) structures have employed Boron steels, HSLA, dual phase materials, foam injected joints, composite inserts, and advanced processing methods like tailor-welded blanks, 4-t welds, deep draw reinforcements, and many other innovative methodologies to improve the stiffness and strength to weight ratios.

While much research has gone into developing AHSS with higher strengths and more formability, the specific stiffness of all grades of steels are still very comparable. Vehicle NVH attributes are almost totally driven by specific bending stiffness which gives aluminum and magnesium a significant advantage. Durability attributes are also somewhat driven by vehicle stiffness but high strength local reinforcements can make up for any local compliance to meet design targets.

So what is a more systematic way for deploying multi-material optimization?

Here is a system that if conformed to, can get you the greatest gains.  Start with a high level topology optimization to see where is the best place to put material. Then consider what the dominant load sets for different regions are.  Put together a spread-sheet of all the materials at your disposal and attributes you have to design to meet:

Cost and weight should certainly be a consideration but you would need to understand the manufacturing methods (stamped, extruded, roll formed, die cast) and volumes, as more often than not, those are larger cost drivers than the material cost per pound. A cursory look at the specific material performance will provide some insight on the weight and associated cost:

If you are looking for bending stiffness, magnesium or aluminum would be my choice. If you need high threshold strength to meet fatigue loads or ultimate loads, HS steel may be good a choice or aluminum if you have the space claim available to package the section size or thickness you need but be mindful of the degradation around the heat affected zones. Of course the complexities associated with joining dissimilar materials (which by itself warrants another blog) must be thought through early.

If you are still not sure on how to mix it up to get the best bang for your buck, contact us at Altair ProductDesign and we’ll be glad to help!

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This month, Altair Partner Alliance’s Vicky Newby had a chance to learn more about the APA’s only Process Structure Interaction tool, CONVERSE. She was able to discuss the interface with OptiStruct, unique applications and benefits, among others with PART Engineering’s very own Sascha Pazour.

Vicky: Why or how was PART Engineering founded? What opportunities were there in the market?

Sascha: PART Engineering was founded in 1999 as a spin-off of the world renowned Institute of Plastics Processing at Aachen Technical University (RWTH), Germany. Starting as a consultancy firm for product development of plastics and rubber parts, PART focused on providing CAE services in the scope of FEA. The Converse and S-Life software products evolved from the company’s need to provide efficient and high-quality CAE tools and services. Today, PART Engineering’s portfolio includes contract CAE simulation and staffing services, as well as CAE software sales. PART Engineering continues to maintain a strong relationship with leading research institutes to ensure that the most cutting-edge technology is considered in its services and software products.

V: What would be the benefits of using CONVERSE for process structure interaction simulation?

S: CONVERSE offers engineers an easy-to-use tool that bridges the gap between injection molding simulation and mechanical simulation by importing the results from a third-party injection molding software, processing them, and then exporting the results into a third-party mechanical FEM software. Overall, this improves the quality of the subsequent simulation results.

V: What are some unique applications of CONVERSE that could be used for specialized projects?

S: All fiber reinforced and most of unreinforced plastic parts need such data Converse provides. In the past this solution was just not provided and FEA specialists tried to predict the behavior without such information. Now they have more possibilities.

V: For industries that wouldn’t normally consider using CONVERSE, what applications or features should they know about that would be of benefit to them?

S: Also, many of our account managers have technical degrees and are therefore able to speak the language of their customers- I do not speak the “engineering language” () and therefore I researched some popular topics among engineering forums and technical papers. If any of these apply to your software, I think the technical readers would find it of interest.

V: How does CONVERSE’s interface with RADIOSS predict part stiffness and failure more accurately than traditional FEA software?

S: Using traditional isotropic material behavior instead of orthotropic material behavior would cause a result that shows the wrong part behavior. The anisotropic material behavior of short fiber reinforced parts can only be considered through using such data.

V: For what applications or projects would you use CONVERSE to map shrinkage and warpage?

S: An example application might be for parts that require FEA simulations done with the exact geometry instead of the ideal CAD-geometry, such as mounted parts.

V: What are the major (essential) inputs required from the user?

S: The main input required is the injection molding results.

V: What other (optional) inputs are required from the user?

S: Users also can provide material information.

V: How much time does it take to learn and start using CONVERSE? (We will link to your collateral, recorded tutorials/webinars here & any planned upcoming events)

S: It takes some hours to learn and understand, but once the procedure is clear Converse is needed just a few minutes each project.

Tool detecting holes from a given range of diameters and creating spiders in each of the holes. Option is given to the user to remove or add holes before the creation.

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Script 894: HyperMesh PowerPoint Report Automation

Script that automates the generation of a PowerPoint report from within HyperMesh. The user can interactively control PowerPoint in order to open an existing presentation, add a slide, add an image, add a h3d or add a table.

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In particular, HyperWorks 12.0 represents significant advancements in three capabilities: design and engineering speed, streamlining complexity and improved product strength. Altair technology leaders have outlined the importance of these elements in product design and the ways that HyperWorks 12.0 can boost the performance in all three areas.

HyperWorks 12.0 can help making your products faster, stronger and lighter 

 

Altair Chief Technical Officer James Brancheau has noted, “HyperWorks 12.0 provides automated and easy-to-use features that save time, ensure accuracy and improve products by making them lighter and offering the opportunity for much more design exploration. The very tight integration and interoperability of the open-platform HyperWorks suite allow users to create and evaluate every aspect of their products with assurance that they have found the best design for their objectives.”

Faster: Accelerate Design

For enterprises, Altair has integrated HyperWorks 12.0 simulation tools with its PBS Works™ workload management solutions to increase high-performance computing (HPC) productivity. The even faster solvers within the HyperWorks 12.0 suite combine with state-of-the-art simulation-based robust design technology to enable users to get the most from the latest HPC and cloud resources.

Ravi Kunju, Managing Director of Strategy and Marketing for Altair Enterprise Solutions, observes that HPC has been in existence for a couple of decades. “What is interesting today,” he says, “is that the cost of hardware cycles is moving from being a capital expenditure to an operational expense with innovative cloud-implementation models. This leads to increased accessibility to infinite resources. Engineers love computations, and this catapults virtual scenario exploration to much greater heights.”

In the HPC world, according to Fatma Kocer, Director of Business Development at Altair, “Studies that were not practical to perform until recently, such as reliability-based design optimizations, are becoming more within reach with the increased computational power that we are all enjoying.

In HyperWorks 12, AcuSolve – Altair’s CFD solver – has drastically improved scalability and efficiency to run simulations in excess of one billion elements.

Capitalizing on that speed is a principal goal of HyperWorks 12.0, says Detlef Schneider, Senior Vice President for Solver Products at Altair. “Part of our vision is that simulation and optimization are driving the product development process, so we need results fast. To do this, we leverage large-scale modern hardware and the latest algorithms.”

As a result, Altair has created scalable solver solutions that run more detailed models and physics and enable optimization so that products can be developed faster.

“Often, time is wasted because modeling is too complex and prone to errors,” notes Paolo Sansalvadore, Senior VP, Modeling and Visualization Products at Altair.  “So the ability of our software to reduce the time it takes for the analysis to be set up and interpreted comes from the ability to automate and debug the analysis that you are performing. The key is to obtain an analysis the first time that is accurate to the level that you need.”

Numerous enhancements in HyperWorks 12.0 help accommodate this need for speed. An entirely redesigned release of HyperStudy accelerates design exploration, robustness, reliability and optimization.  The suite’s best-in-class optimization capabilities speed the lightweighting of designs and, in OptiStruct, include new manufacturing constraints for composite materials.

In HyperWorks 12.0 many features are available to efficiently model and analyze complex composites parts, including 3D representation of plies

Also, HyperMesh in HyperWorks 12.0 incorporates advanced meshing algorithms for shell and solid meshing, such as a mid-plane mesh generator with automatic thickness mapping from complex solid CAD geometry and the addition of quality control mechanisms. The implicit solvers in RADIOSS, OptiStruct and AcuSolve add GPU support with a cost-effective licensing schema, and a novel multi-core licensing model for multiphysics simulation capitalizes on HyperWorks and Altair Partner Alliance solvers for solving high-end problems.

Streamlining Complexity: An Improved User Experience

HyperWorks 12.0 is inherently talented at making the most complex problem simple. It adopts an improved user experience to set up and solve the most intricate simulation projects to design better, lighter products with ease. New, modern approaches to graphical user interfaces, for example, replace property-area technologies. HyperWorks 12.0 also furnishes on-screen manipulators, context-sensitive menus and new infrastructure for faster implementations.

Much of today’s complexity derives from hit-and-miss methodologies for finding the right combination of size, shape, materials and overall design. “Companies have been using trial-and-error processes for their design,” Kocer notes, “and moving from that to using concept design optimization is a change in the mindset for engineers, designers and analysts.”

“What we’re trying to do with tools like solidThinking Inspire,” points out Altair Senior Vice President for Design and Math Products James Dagg, “is to put topology optimization into an environment that the designer is more used to, a more design-friendly setting. Inspire increases the depth of innovation for designers, enabling them to explore entirely new design concepts for structural parts. When you get the design right from the beginning, you can be more responsive to the marketplace, you can be more innovative and you can create products that perform better.”

solidThinking Inspire puts topology optimization in a more design-friendly environment, making it accessible to more engineers, designers and analysts

With Inspire in HyperWorks 12.0, designers can generate and explore structurally efficient concepts in the earliest phases of the design process, while solidThinking Evolve delivers a NURBS-based 3D modeling and rendering environment to create manufacturable models and render CAE results with unsurpassed photorealism.

A number of HyperWorks 12.0 enhancements contribute to this streamlining of processes. For example, HyperMesh and HyperView now provide easy access to CAE technology, including improvements to model browsers; a new streamlined user profile (BasicFEA) for quick model setup; and various sophisticated model assembly methods, including an automated connectors generation method, yielding faster assembly of complex models. One of the most interesting new functionalities of HyperView is its support for viewing results in 3D.

“The new 3D capability creates a fully immersive environment that improves our ability to support conceptual design and analysis efforts,” reports Jonathan Gabrys, Technical Fellow at The Boeing Company. “Specifically, being able to interrogate complex analysis results, such as stress fields or deflections, using 3D visualization provides an enhanced level of understanding.”

Stronger: Simulate Everything

Manufacturers today are expressing considerable interest in alternative materials for components, systems and entire structures, from racecars to airlines. These new materials require new modeling methods. HyperWorks 12.0 improves the interoperability with CAD systems, in particular for composite modeling. For example, it introduces new readers for composite modeling data.

“Another trend we are seeing,” Schneider says, “is our customers wanting to do more multiphysics-type solutions. With our broad offering, including our partner alliance, we actually are able to provide those multiphysics simulations on different levels. We are coupling our codes in a most efficient way to solve real-world problems with high performance and quality.”

Other enhancements in HyperWorks 12.0 include powertrain durability and large-scale NVH analysis and optimization. New and enhanced functionalities enable, for instance, one-step transfer path analysis and a multi-level sub-structuring solver (AMSES) in OptiStruct. CAD import and export interoperability is enhanced, as are composites interfacing and collaborative simulation data. In addition, several new material laws and failure models are incorporated into the RADIOSS solver for improved accuracy.

HyperWorks 12.0 offers a complete solution for powertrain durability analysis and optimization

Finally, HyperWorks 12.0 comes with one other unparalleled feature: the Altair Partner Alliance, with specialized software applications developed by nearly 30 different partners, all of which are directly accessible using current HyperWorks units.

Explore HyperWorks 12.0 and discover how it can make your engineering processes faster, simpler and stronger, speeding your products to market and helping ensure they meet your customers’ toughest demands.

Then, if you like, let us know what you think by filling out this three-question survey

Useful Links:

• Additional information about the release
• Rollout webinar series
• HyperWorks on-line learning

To cover the required development tasks Altran used HyperWorks tools such as MotionView, OptiStruct, HyperMesh, HyperView and RADIOSS within the development process of the concept car.

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