Lightweight design in body engineering: simulation as the key
During the ASC-S Simpulse Day in Hanau in April 2025, Dr André Backes gave a presentation on how simulation-based methods can optimise lightweight design structures. During the workshop, the TECOSIM Technical Manager showed how CAE (computer-aided engineering) helps to achieve CO₂ targets. The event organiser was ASCS e. V., a platform for innovation, technology transfer and cooperation in the fields of AI, simulation and high-performance computing (HPC).
What lightweight design means for mobility
In passenger transport – whether by road, rail, or air – each individual is typically moved along with around one ton of mass, far exceeding their own body weight and luggage. The kinetic energy required to accelerate a mass (m) to a specific speed (v) is calculated using the formula E = 0.5 * m * v². This formula shows the linear correlation between mass and the energy required. To reduce energy consumption, lightweight design needs to be advanced systematically. The aim is to reduce the structure mass without overlooking stiffness requirements.
Simulation-based optimisation of lightweight structures
Virtual development affords opportunities to enhance lightweight design structures through a targeted approach. One example is a body in white with its numerous metal sheets. An optimised metal sheet thickness distribution can reduce the overall structure mass significantly while still meeting all rigidity requirements. A PIDO tool such as pSeven can implement this optimisation method across multiple disciplines while simultaneously taking into account requirements from areas such as crash safety, NVH and durability.
Detail and topology optimisation
In addition to metal sheet thickness optimisation, individual components can also be improved in detail. Seam optimisation ensures optimal distribution of seams and formed features to enhance rigidity without increasing the sheet metal thickness. Topology optimisation offers the greatest flexibility as it defines a component’s shape and details within the available installation space. In this way, you can determine the ideal rib structure for a cast part, for example.
Optimized design for parametrised geometry
Another way to optimise a structure’s design is through parametrised geometry. This can be done using the ANSA software morphing tool by Beta CAE Systems, for example. The first step is to define morphing parameters to describe specific shaping actions in the ANSA model. The pSeven PIDO software will then automatically optimise these parameters iteratively to comply with rigidity and lightweight construction requirements.
Lightweight design for electric vehicles
The battery in electric vehicles often weighs as much as the body in white, if not more. Consequently, it is essential to produce a coordinated design between the body in white and the battery structure. The aim is to integrate the battery in a way that enhances body rigidity and delivers a lightweight structural design.
Conclusion
A successful lightweight design concept takes into account many structural requirements at an early stage of the development process. If elements such as NVH comfort are omitted, additional materials must be used at a later stage to achieve acoustic objectives, which then increases weight. Integrating all requirements early on reduces mass and creates more efficient structures. Simulation-based optimisation methods, as Dr André Backes presented them, offer sustainable, future-proof solutions for tomorrow’s mobility.
