From Structure To Sound: Unlocking The Potential Of Vibroacoustic Design
Interview with Vanessa Cool – Ku Leuven
Introducing vibroacoustic simulation into topology optimization brings another dimension of complexity, but also new possibilities for structural performance and sound control to mechanical parts and systems.
At CDFAM Amsterdam 2025, Vanessa Cool will present computational frameworks that integrate both acoustic and structural objectives into the early stages of design.
Currently a postdoctoral researcher at KU Leuven, her work focuses on sandwich meta-structures, reduced order modeling, and optimization strategies that account for dynamic, frequency-dependent behavior.
In this interview, she discusses how these methods differ from traditional structural optimization, the challenges of scaling across unit cells and full components, and the types of industries that stand to benefit most from vibroacoustic-aware design.
Can you start by telling us what you will be presenting at CDFAM Amsterdam, and why is vibroacoustic design becoming a critical focus in modern structural optimization?
I’ll be presenting comprehensive frameworks for vibroacoustic topology optimization—methods that don’t just optimize for structural performance, but simultaneously consider how a structure behaves acoustically.
This is crucial because noise pollution has become one of the leading global environmental challenges, with real health implications.
At the same time, industries are under pressure to meet increasingly strict acoustic regulations without sacrificing mechanical performance or increasing weight.
By incorporating vibroacoustic coupling from the early stages of design, we can automatically create structures that are not only lightweight and stiff but also acoustically optimized.
This often results in new deformation patterns that are leveraged by the optimizer—patterns that would be difficult for a human designer to predict or conceive using traditional intuition.
Figure 1. Example of a vibroacoustic topology optimization framework for the design of sandwich panel cores. Both the structural performance, acoustic performance and weight is considered during the optimization leading to intricate optimized designs exploiting non-intuitive deformation patterns [1].
What are some of the biggest challenges of introducing vibroacoustic coupling at the early stages of topology optimization, compared to traditional structural optimization?
The main challenge lies in the complexity and computational cost.
Unlike traditional topology optimization, where we might focus on stress or compliance, vibroacoustic optimization involves simultaneously solving the structural and acoustic domains—and how they interact. This coupling adds multiple layers of physics to the problem, making the optimization process more sensitive and computationally demanding.
Additionally, structural and acoustic performance goals often conflict with each other, making trade-offs difficult to manage—something the optimization process helps handle by finding balanced solutions.
Figure 2. Example of the inherent trade-off between structural and acoustic performance for a unit cell bandgap optimization [2].
Moreover, acoustic performance is often governed by frequency-dependent phenomena. So, we’re not just optimizing a single static behavior, but across a range of dynamic responses.
That makes the design space more intricate—but also opens up fascinating possibilities for novel designs that wouldn’t emerge through traditional methods.
You’ve worked across different scales in your research, from unit cells and metamaterials to supercell and full component structures. How does the design logic or optimization strategy shift when moving between these scales?
At the unit cell level, optimization targets general performance metrics like wave propagation and bandgap behavior, typically under idealized periodic boundary conditions. In contrast, at the component level, the focus shifts to application-specific objectives such as sound transmission loss or vibration response, modeled with more realistic boundary conditions.
This makes unit cell optimization computationally efficient and effective for exploring broadly applicable design concepts. However, the absence of real boundary interactions can limit its predictive accuracy when transitioning to full-scale structures.
Component-level optimization provides greater design freedom and more realistic results—thanks to the inclusion of actual boundary conditions—but it comes with significantly higher computational cost and often leads to more intricate, complex designs.
Navigating between these scales involves clear trade-offs: unit cell optimization enables speed and generality, while component-level design provides fidelity and functional precision.
Figure 3. Comparison between unit cell till component optimization strategies.
Topology optimization often aims for lighter, stiffer structures. How does the added constraint of acoustic performance reshape the kinds of geometries and material distributions you are seeing?
Incorporating vibroacoustic performance into topology optimization significantly changes the design landscape, which results in large alterations of the obtained material distribution.
Whereas for example compliance minimization typically leads to load paths and truss-like structures that align with engineering intuition, vibroacoustic optimization operates in a complex and highly non-convex design space characterized by strong multiphysics coupling and frequency-dependent behavior.
The optimization must now account for how the structure behaves dynamically—how it vibrates, how those vibrations radiate sound, and how these effects interact. This dynamic coupling reshapes both the global layout and the fine-scale features of the design, often resulting in novel configurations that challenge traditional assumptions about optimal structures.
The resulting geometries often exhibit highly non-intuitive, intricate topological features, blending stiffness with a clever redirection of the sound waves.
Moreover, the complexity leads to a large number of local minima, meaning that small changes in parameters or initial conditions can result in entirely different optimal designs.
For engineers and designers not yet familiar with vibroacoustic optimization, what kinds of products or industries could most immediately benefit from integrating this kind of design approach?
The most immediate applications are in aerospace, automotive and building acoustics.
Think of aircraft cabins, electric vehicles, or speaker housings—areas where noise control and mechanical functions are deeply intertwined.
By integrating vibroacoustic design early on, companies can reduce post-design fixes like damping layers or soundproofing, and instead build the required vibroacoustic performance into the structure itself.
Even industries like medical devices or sports equipment—where user comfort and sensory feedback are key—could benefit.
The challenge is convincing stakeholders that this early investment in simulation and optimization will pay off with better products and reduced prototyping.
What are you most looking forward to learning or sharing with the broader computational design community at CDFAM in Amsterdam?
I’m most excited to connect with other researchers and designers who are exploring similar design complexities—from multiphysics problems to strategies across scales.
CDFAM is a unique community where academic research meets real-world application, and I look forward to exchanging insights on how advanced optimization could benefit industry.
Lastly, I also hope to share that acoustic considerations don’t need to be an afterthought—they can be creatively integrated into the design process. And with the right computational tools, we can push the boundaries of what optimized structures can achieve.
To see whether her work resonates with your own design challenges, connect with Vanessa Cool and others exploring a broad range of design and engineering questions at CDFAM Amsterdam 2025.
Registration is now open, with limited capacity at the two day, in-person event.
For further reading, explore our previous articles on key themes from the CDFAM community. Simulation-Driven Design, Engineering & Architecture offers an overview of presentations where simulation plays a central role in shaping performance-driven geometry across architecture, aerospace, and product design.
In Machine Learning and AI in Engineering: From Concept to Fabrication we examine how presenters are beginning to integrate AI into engineering workflows—highlighting the realities of data preparation, domain-specific model training, and the limits of current tools. Together, these pieces provide broader context for how computational methods are transforming design practice across scales and industries.
[1] Cool, V., Sigmund, O., Aage, N., Naets, F., Deckers, E. (2024). Vibroacoustic topology optimization for sound transmission minimization through sandwich structures. Journal Of Sound And Vibration, 568, Art.No. 117959.
[2] Cool, V., Sigmund, O., Aage, N. (2025). Metamaterial design with vibroacoustic bandgaps through topology optimization. Computer Methods In Applied Mechanics And Engineering, 436, Art.No. 117744
