Metal Forming Simulation for Product Development.

Have you ever noticed the evolution we've had in car models over the past 50 years?

It is remarkable that cars have transitioned from a 'simple' design to modern, bold designs, full of curves and lines that strengthen the 'identity' of the brands.

However, it wasn't just the designs that changed. Along with this change came other factors such as legislation on pollutant emissions and vehicle safety in collisions.

It is fascinating to visit comparisons of the famous crash tests and see the evolution we have had on this important factor. In the image below, you can notice the evolution of vehicle structures against collisions, where the vehicle on the left shows almost no damage in the driver and passenger area, whereas the vehicle on the right does not fare as well.

In the race to minimize vehicle pollutant emissions, manufacturers have been working tirelessly for years to reduce vehicle weight, which also results in better performance and greater distance traveled with lower fuel consumption, essentially. This brings greater competitiveness to the brands.

All these factors contribute to the relentless effort in developing new products, applying new, much more resistant raw materials, thus allowing for the use of thinner materials, reducing vehicle weight while still providing greater safety for the driver and passengers.

As a result, the challenges of product engineering are enormous, especially when developing a vehicle with bold designs and strategically reinforced high-strength steel. This includes reducing structural thicknesses, replacing them with smaller reinforcements, or even eliminating components.

And how can ensure that the design and the chosen materials are suitable for stamping processes?

With the design and raw material defined, will the manufacturing process be complex?

What are the impacts on manufacturing and project costs?

As mentioned in the previous article, simulation software for stamping is on the rise in the global industry. In this article, I will explore some applications, focusing specifically on opportunities for product engineering. Below are some possibilities:

1. Analyzing stress states in the design + material characteristics – This application provides the product engineer with a clearer view of stress levels in the raw material distributed throughout the product geometry. It facilitates a critical analysis of complex and strategic regions. With simulation, the engineer can assess the product's stampability and make design or material option modifications as needed.
2. Validate the design for subsequent phases – During the product development and analysis phase, it is possible to identify critical regions of stress accumulation and excessive thinning of thickness. Product engineering can then request a meeting with process engineering to analyze these points and validate whether they can be managed in the process or if they will incur excessive costs to the project.
3. Identify potential defects that originated with the product itself and not from any stage of the manufacturing process – For external parts of products, such as the exterior of the car, they are considered aesthetic items that require a higher standard of quality, free from visual defects. With simulation, it is possible for the product engineer to identify potential surface defect trends arising from the design itself in advance. During my work in this field, I have had the opportunity to participate in discussions at major automakers about such defects, which trigger numerous discussions between process engineering and quality control departments, in an attempt to eliminate a defect that they believe arose during some phase of the manufacturing process, when in fact the defect 'was born' with the product, as confirmed by simulation.
4. Directing product design toward a more favorable manufacturing process, with the lowest possible production cost – This application is crucial for the project budget. In conversation with a professional colleague, Carlos L. , who was an exceptional product engineering professional at renowned automakers Volkswagen do Brasil and General Motors South America , he mentioned that engineers responsible for each item must understand costs such as raw materials and production. Previously, estimates were based on past experiences and professional knowledge, and manufacturability was validated only with physical prototypes. Today, with simulations, it's possible to assess the product's stampability and study the use of materials based on design and material characteristics, resulting in more precise financial control. Another example is automakers advancing in product engineering phases, conducting in-depth analyses of strategic products, considering process simulations, and making improvements in design and materials to favor production processes, generating significant economic gains. For more information, I recommend the following article that I had the opportunity to co-author with the product engineering team at Stellantis South America (https://formingworld.com/stellantis-brazil-cost-reduction/).
5. Implementation of improvements such as vehicle weight reduction – Well, for this application, as discussed in topic 1, simulation tools allow analyzing the stress distribution of the material on the 3D model of the product, where it's possible to identify critical regions such as wrinkles, fractures, excessive thinning, among other factors, all in a simple and quick manner. This facilitates studies of different types of materials, considering their mechanical characteristics and their influences on designs. Currently, most major steel mills worldwide use these software tools to develop their products (steels), compatible with production processes and meeting performance and quality requirements defined by engineering.
6. Nationalization changes – Another application in which simulation resources are very useful is for the nationalization of items. Some automakers develop their products in other countries, as is the case with many Asian automakers. However, in the vast majority of projects, it is necessary to make some changes to certain items in order to adapt the vehicles to the stress conditions they will be subjected to, such as highways, streets, etc. For this purpose, these modifications can be validated and controlled by all the topics mentioned above, i.e. manufacturability, critical regions, a study into the use of equivalent materials, since raw materials from other countries have their own particularities, and financial/cost control of the items for the project budget.

There are many applications and benefits of simulation in product engineering.

In addition to the mentioned applications, current resources allow extending simulation to the development of assemblies and body-in-white (BiW). This includes the development and definition of welding sequences, identifying assembly distortion trends due to welding processes and stamping springback, estimating welding cycles, and developing devices without oversizing, among others. I won't go into details on this topic, as there is enough content for another article.

Trends

Considering that current process simulation technologies provide results such as stress distribution, dimensional variations from the process, thickness thinning, among other factors. Some European automakers are already considering importing a fully simulated car body, with its stress states resulting from the manufacturing process, thus obtaining a more realistic scenario for crash test simulations and failure/fatigue tests.

Conclusion

For product engineering, what we can observe is a significant gain in project delivery time. I have witnessed reports of project lead-time reduction by up to 3 months in the product engineering phase. Additionally, there is greater financial control, as it is possible to study and work with designs and materials that favor the manufacturing process and reduce or eliminate the need for physical prototypes, which consume time and costs.

I hope you have enjoyed this article. Please leave your reaction or comment to let me know you liked it.

If you see any other applications beyond those mentioned in this article, we would appreciate it if you could share them with us in the comments.

Thank you for reading!

Best regards,

Edson Rodrigues