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Dream up Your Most Innovative Lightweight Designs with Topology Optimization

How can you go about making your product more lightweight and reducing manufacturing costs – without sacrificing performance or safety? What if switching from steel to new lightweight material isn’t an option? We will address these topics and more in this blog.

Wednesday, May 12, 2021
By Sandrine Dischert

The lighter the products, the cleaner the air

According to the United States Environmental Protection Agency, the largest sources of transportation-related greenhouse gas emissions include passenger cars and light-duty trucks, including sport utility vehicles, pickup trucks, and minivans. The remainder comes from other sources, with aircrafts topping the list. Governments realized the gravity of the situation and answered the call by setting targets to reduce consumption and CO2 emissions. So, how have auto and aircraft manufacturers learned to mitigate this problem?

Lightweighting, or reducing vehicle weight, is the most adopted method of reducing energy consumption and its by-product, CO2 emissions. New materials like advanced high-strength steel (AHSS) and composites have been a major step in this area; they are much lighter than steel and can reduce total vehicle weight by up to 10% as opposed to traditional steel. Lightweighting is of particular interest to electric vehicle OEMs in their continuous effort to increase range.

The same rings true for aerospace manufacturers facing the two-fold challenge of further reducing fuel consumption (accounting for up to 30% of ownership cost) and the urgent need to reduce the environmental footprint by lowering emissions. While lightweight alloys have been widely deployed in aircrafts to decrease the weight-to-strength ratio, there is still a need for further reduction. Among the breakthrough technologies, Additive Manufacturing is unleashing a wider design space to redesign lightweight parts that can be manufactured at a reasonable cost and a quick time to market. It is also paving the way for innovative and complex parts, integrating several functions, and creating even more weight and cost savings.

Topology optimization makes way for new, lightweight designs

How, then, does one go about making a product more lightweight and reducing manufacturing costs – without sacrificing performance or safety? And what happens when switching from steel to new lightweight material isn’t an option? How do companies using additive manufacturing arrive at an optimal design?

Let’s reflect on how products are typically created. You think up a design and then you focus on bringing that design to life through ad-hoc manufacturing capabilities used on industrial production lines. But what if, instead, you were able to create a completely new and lighter design, and would identify constraints early on in the manufacturing stage?

Topology optimization is a technology used by many designers to change the shape of a part by whittling away at the material. The end goal is to find the best shape that fully respects a set of given constraints. One of the constraints can be reducing volume or weight, which makes the part lighter.

The first generation of optimization solutions uses a material density approach (SIMP method). This technology has allowed the emergence of new designs. But its limitations have encouraged the search for new methods to further push the limits of innovation in the service of design. ESI has developed a new method addressing this gap, to define an optimal shape.

Most of the widespread topology optimization solutions on the market use a material density approach (SIMP method) mainly because it is easier to implement. The problem with this approach is that, at the end of the process, the user isn’t left with the optimal shape but, instead, with several solutions depending on the threshold chosen. In addition, the chosen resolution methods do not make it possible to fully comply with the imposed specifications

The topology tool with the winning combination

Several years ago, ESI started developing TOPAZE, a new generation solution for Topology Optimization based on the level-set method. The benefit is a unique final shape with a better-defined contour, which respects the constraints set by the designer.

The application also features a new CAE Return tool. With this tool, designers easily verify their optimization results or reintegrate the new design in their dimensioning process. This opens the door for users to perform the complete circle of the optimization process, starting from a mechanical model through to the same model with the final optimum shape.

The topology optimization process. Courtesy of Renault.

Additionally, with TOPAZE, designers account for manufacturing constraints very early on. For example, molding constraints and symmetry of the results can be applied at an early stage so that solution is guaranteed to comply with the casting manufacturing process.

Test case optimization, with molding constraints.

TOPAZE lends a helping hand to the 3D printing world

With the advent of additive manufacturing, typical constraints of the design process are eradicated and all shapes are acceptable. Users optimize their components with TOPAZE and then export the design for later use with 3D printing.

Coupled with ESI’s Additive Manufacturing Solution, TOPAZE is used to optimize the shapes of the supports needed during the manufacturing process, which happens on an experimental level.

The process of optimizing supports needed for additive manufacturing

Looking to the future, ESI is working to further define specific additive manufacturing constraints and integrate them into the topology optimization process.

ESI partners with OEMs to continue pushing the bounds of innovation

TOPAZE is an innovative application and its development is supported through participation in collaborative projects such as the TOP project (Topology Optimization Platform) with industrial partners Renault and AIRBUS, and the SOFIA project (Solutions for Industrial Metal Additive Manufacturing) with partner AddUp and many others.

The TOP Project

TOP is a four-year program with three principal objectives:

  • Scientific breakthroughs in the field of optimal design
  • Develop innovative and robust digital tools to deal with the design requirements of complex structures
  • Demonstration of the reliability of these tools on industrial cases provided by end-user partners

Through the TOP Project, Harmonic Response, dynamic criteria, was developed and completely integrated into TOPAZE.

The SOFIA Project

SOFIA is a six-year applied research program aimed at developing a complete metal additive manufacturing value chain (powders, production equipment, processes).

This project will enable the development of new constraints related to the additive manufacturing process and integrate them into TOPAZE. The ultimate will goal will be that the final optimal shape predicted by TOPAZE can be directly manufactured via additive manufacturing solutions.

Keep following these projects and ESI for the most cutting-edge developments related to shape optimization and how it can benefit you.

For more information on optimizing your lightweight designs, download a white paper on multi-material assemblies.

For more information on the projects, visit TOP and SOFIA.

Sandrine Dischert

Domain Leader for the Energy Sector

Sandrine Dischert is currently the Domain leader for the Energy sector at ESI Group. She leads the teams for ESI’s Multiphysics solution, ESI SYSTUS – an industry solution to pre-qualify new component designs in accordance with nuclear industry regulations – as well as TOPAZE – a specific module for topology optimization. Her focuses are market analysis, technology & economic watch, innovations – identifying which new technologies can address customer outcomes.

To carry out her mission, she relies on more than twenty years of experience in the field of energy during which she first carried out component studies, developed dedicated tools and then became a technical manager of a consulting team of engineers.