• The state-of-art of lightweight materials for automobiles is reviewed. • Representative materials are introduced with potential automotive applications, particularly on electric vehicles. • Given the recent advances in manufacturing, modeling, and characterization, both pros and cons of materials are summarized. • Solutions for future challenges are highlighted by developing advanced materials and/or improving the manufacturing. The growing challenges on fuel economy improvement and greenhouse gas emission control have become the driving force for automakers to produce lightweight automobiles. Also, the weight reduction may contribute to superior recyclability and/or vehicle performance ( e.g ., improved driving economy, braking behaviors, and crashworthiness). One effective strategy is to develop and implement lightweight yet high-performance materials as alternative solutions for conventional automotive materials such as cast iron and steel. Herein, a systematic review of available lightweight materials to produce next-generation automobiles is provided, including light alloys, high-strength steels, composites, and advanced materials in the ongoing research. By investigating the entire life cycle of automotive materials, physical/mechanical properties, characterization, manufacturing techniques, and potential applications of specific lightweight materials are discussed. Both the advantages and drawbacks of the reviewed materials are summarized, yielding the appropriate application scenarios for different lightweight materials. Given the future challenges, on expectations, the development of versatile advanced materials or improvement of the manufacturing/treatment techniques can be rather promising to resolve the possible bottlenecks and, in turn, enables more capable, safer, durable, and environmental-friendly vehicles. 

Advanced Lightweight Materials for Automobiles: A review

This study proposed a new bio-inspired hierarchical circular honeycomb (BHCH), mimicking the hierarchical structures from wood. The mechanical properties and energy absorption characteristics of the proposed structures were investigated by means of quasi-static compression tests and finite element (FE) analysis. Subsequently, the influences of geometric parameters and material selections on the energy absorption capacity were investigated. The experimental results and parametric study indicated that the BHCH outperformed the conventional circular honeycomb (CH) in terms of energy absorption capacity. Specifically, the BHCH had a higher specific energy absorption (SEA) than the corresponding CH with the same wall thickness (i.e. 45.3%) and the same volume of honeycombs (i.e. 71.2%). Furthermore, the relative stiffness, relative strength, and relative energy absorption of the BHCH were significantly higher than other popular cellular structures. Finally, a theoretical model was developed to estimate the mean crushing stress (MCS) and interaction effect of the proposed structure, which further demonstrated its enhanced energy absorption mechanisms. A good correlation between the predicted values and the numerical results proved the reliability of the proposed analytical models. With its excellent performance, the proposed BHCH provided a promising solution for the enhanced energy absorption of the honeycomb structure used in a wide range of applications from structural components of defence structures to protection systems in vehicles. 

Mechanical properties and energy absorption of bio-inspired hierarchical circular honeycomb

Dynamic behaviors of bio-inspired structures: Design, mechanisms, and models

Uncover the underlying mechanisms of topology and structural hierarchy in energy absorption performances of bamboo-inspired tubular honeycomb

Crashworthiness analysis of bio-inspired hierarchical circular tube under axial crushing

https://link.springer.com/content/pdf/10.1007/s10338-021-00262-8.pdf

John Sherman

Papers

Energy Absorption Performance of Bio-inspired Honeycombs: Numerical and Theoretical Analysis