Beyond aluminum foam: lightweight PEEK honeycomb emerges as new champion for car crash safety

Researchers have designed a new energy-absorbing component for cars using a regular hexagonal polyether ether ketone (PEEK) honeycomb core. This innovative design boosts the average crash load by 18.1% compared to standard hollow structures while being approximately 19% lighter than conventional aluminum foam fillers. It achieves an ideal balance between superior crash protection and vehicle lightweighting, demonstrating significant potential for the next generation of vehicles.

In low-speed collisions, which account for the majority of traffic incidents, a car's front-end energy-absorbing box is its first line of defense. While filling these boxes with materials like aluminum foam can improve safety, it often comes with a heavy weight penalty. Now, a research team from Dalian Jiaotong University has developed a breakthrough solution using the high-performance thermoplastic PEEK.

The team engineered an energy-absorbing box with an aluminum shell filled with a PEEK honeycomb core. Through advanced computer simulations, they systematically compared this new design against traditional hollow and aluminum foam-filled structures.

"The quest in automotive safety is to find a material that is incredibly strong yet very light," said Professor Xinlin Wang, corresponding author of the study. "PEEK's exceptional specific strength and toughness, arranged in an efficient regular hexagonal honeycomb pattern, allowed us to make a significant leap forward."

The results, published in the journal Advanced Manufacturing, were clear. The aluminum foam filler, while absorbing energy, was heavy and generated high peak forces. The regular hexagonal PEEK honeycomb, however, achieved a superior balance. It increased the average crushing load by 18.1% over the hollow design, ensuring more stable and efficient energy dissipation. Crucially, it accomplished this while being significantly lighter than the aluminum foam option, highlighting its exceptional specific energy absorption.

"The PEEK honeycomb collapses in a stable, progressive manner, like a predictable and efficient shock absorber," explained Wenqiang Yue, the paper's first author. "This controls the vehicle's deceleration more smoothly and helps preserve the integrity of the passenger cabin within a very limited deformation space." This makes the design particularly valuable for modern vehicles where space is at a premium.

Looking ahead, the team identifies promising future directions, including optimizing PEEK honeycombs via 3D printing and employing deep learning for intelligent design. They also envision developing programmable configurations that could adapt to different crash scenarios.

"This research provides a compelling theoretical foundation and a practical candidate for the next generation of automotive safety systems," Professor Wang added. "As the industry pushes towards greater efficiency and safety, such high-performance, lightweight composites are poised to play a key role."

Yue W, Wang X, Wang X, Guan T. Design of honeycomb energy-absorbing box and its low-speed crashing behaviour for automobiles. Adv. Manuf. 2025:20250009. https://doi.org/10.55092/am20250009

Media Contact:
Wenqiang Yue
Dalian Jiaotong University
1450513119@qq.com
13845742611

Expert Contact:
Professor Xinlin Wang
Dalian Jiaotong University
wxl_me@djtu.edu.cn