Futuristic car crash scene, emphasizing energy absorption and material deformation during multiple impacts, made of CFRP and aluminum.

Crash Course: How New Materials Could Revolutionize Car Safety

Soraya Malik in Tech & Innovation June 2025 • 4 min read.

"Innovative composites and alloys promise to make vehicles lighter, stronger, and safer in repeated crash scenarios."

In the relentless pursuit of enhanced vehicle safety, automotive engineers are increasingly turning to advanced materials that offer a unique blend of lightweight properties and superior energy absorption. Traditional materials are being challenged by innovative alternatives, with thin-walled carbon fiber reinforced plastics (CFRP) and aluminum (Al) structures emerging as frontrunners due to their ability to significantly reduce vehicle weight while maintaining or even enhancing structural integrity.

One critical aspect of vehicle safety that demands attention is the ability to withstand multiple impacts, a common scenario in severe traffic accidents such as pile-ups. During these events, the front and back rails of a vehicle's body may experience a series of impacts, making accumulated plastic deformation and progressive folding key factors in determining crash fatality risk. Therefore, understanding and quantifying the impact response and residual properties of vehicle components under repeated impact scenarios is crucial to ensure safety and reliability on the road.

While extensive research has been conducted on single-impact crashworthiness, the behavior of composite and aluminum tubes under repeated axial impacts remains relatively unexplored. A new study detailed in Composite Structures journal addresses this gap, presenting an experimental investigation into the energy absorption capabilities of CFRP and Al tubes subjected to repeated axial impacts and subsequent crushing. The findings offer valuable insights into the potential of these materials to improve vehicle safety in complex, real-world crash scenarios.

The Science of Multiple Impacts: CFRP vs. Aluminum

Futuristic car crash scene, emphasizing energy absorption and material deformation during multiple impacts, made of CFRP and aluminum.

The experimental study focused on thin-walled CFRP and aluminum tubes, mimicking key crash elements in vehicle structures. The tubes were subjected to five repeated impacts at the same energy level to assess the effect of repeated impact number on their structural behavior. Following the impact tests, the tubes underwent crushing tests to determine their post-impact residual properties.

Key observations from the dynamic impact tests:

CFRP Tubes: Exhibited progressive end crushing modes under repeated dynamic impacts, with the highest specific energy absorption (SEA) during the first impact, followed by consistent SEA values in subsequent impacts.
Aluminum Tubes: Displayed stable progressive folding, with SEA values fluctuating based on the formation of different folds during each impact.
Residual Properties: Quasi-static crushing tests revealed that the residual SEAs of both CFRP and aluminum tubes were not significantly affected by the number of impacts, remaining within a 5% difference after five repetitive impacts.

These results underscore the distinct behaviors of CFRP and aluminum under repeated impacts. CFRP demonstrates a more consistent energy absorption capability, while aluminum's performance is closely tied to its deformation mode. However, it was also demonstrated that the CFRP tubes had much better performance in energy absorption capability in comparison with the aluminum tubes in terms of repeated impacts and residual crushing tests.

The Road Ahead: Implications for Vehicle Design

This research provides valuable insights for automotive engineers seeking to design safer vehicles. The superior energy absorption of CFRP under repeated impacts suggests its potential for use in critical areas of vehicle structures, offering enhanced protection in multi-impact collisions. While aluminum also demonstrates energy absorption capabilities, its performance variability highlights the need for careful design considerations to maximize its effectiveness. By strategically incorporating these advanced materials, manufacturers can create vehicles that better withstand real-world crash scenarios, ultimately reducing injuries and saving lives.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.compstruct.2018.04.001, Alternate LINK

Title: Crash Responses Under Multiple Impacts And Residual Properties Of Cfrp And Aluminum Tubes

Subject: Civil and Structural Engineering

Journal: Composite Structures

Publisher: Elsevier BV

Authors: Qiang Liu, Hao Shen, Yinghan Wu, Zhencong Xia, Jianguang Fang, Qing Li

Published: 2018-06-01

Everything You Need To Know

Why are materials like Carbon Fiber Reinforced Plastic (CFRP) and Aluminum being explored for vehicle safety?

In the context of vehicle safety, CFRP, or Carbon Fiber Reinforced Plastic, and Aluminum are being explored because they offer a unique combination of being lightweight and having superior energy absorption properties. Traditional materials are being replaced due to CFRP and Aluminum structures significantly reducing vehicle weight while maintaining, and sometimes enhancing, the structural integrity of the car. The use of these materials are being explored due to their promise of making safer and lighter vehicles that are better capable of withstanding repeated crash impacts.

What was the methodology behind the experiment detailed in the Composite Structures journal regarding CFRP and Aluminum tubes?

The study in Composite Structures journal examined thin-walled CFRP and Aluminum tubes, replicating vehicle crash elements, under five repeated impacts at the same energy level, followed by crushing tests. The goal was to assess how repeated impacts affect their structural behavior and post-impact residual properties. The research focused on the materials' behavior under repeated axial impacts, which is crucial for understanding crash fatality risk in accidents like pile-ups, where vehicles experience a series of impacts.

What were the key differences observed in the behavior of CFRP and Aluminum tubes during the dynamic impact tests?

CFRP tubes exhibited progressive end crushing modes under repeated dynamic impacts, demonstrating the highest Specific Energy Absorption (SEA) during the first impact, with consistent SEA values in subsequent impacts. Aluminum tubes, on the other hand, displayed stable progressive folding, but their SEA values fluctuated based on the formation of different folds during each impact. The study demonstrated that CFRP tubes had much better performance in energy absorption capability in comparison with the aluminum tubes in terms of repeated impacts and residual crushing tests.

How were the residual properties of CFRP and Aluminum tubes affected by repeated impacts, according to the study?

The research showed that the residual Specific Energy Absorption (SEA) of both CFRP and Aluminum tubes remained within a 5% difference after five repetitive impacts. This indicates that the number of impacts does not significantly affect the residual properties of these materials. Following the impact tests, the tubes underwent quasi-static crushing tests to determine their post-impact residual properties. This is crucial for understanding how the materials behave after an initial collision and their ability to provide continued protection in subsequent impacts.

What are the potential implications of this research for automotive engineers and the design of safer vehicles?

The superior energy absorption of CFRP under repeated impacts suggests its potential for use in critical areas of vehicle structures, offering enhanced protection in multi-impact collisions. While Aluminum also demonstrates energy absorption capabilities, its performance variability highlights the need for careful design considerations to maximize its effectiveness. By strategically incorporating advanced materials like CFRP and Aluminum, manufacturers can create vehicles that better withstand real-world crash scenarios, ultimately reducing injuries and saving lives. This research could lead to lighter, stronger, and safer vehicles that are better equipped to protect occupants in a variety of accident scenarios.