Multifunctional Hybrid Fiber Composites for Energy Transfer in Future Electric Vehicles.

Area of Science:

• Materials Science
• Electrical Engineering
• Aerospace Engineering

Background:

• Reducing weight in electric vehicles, especially aircraft, is critical for energy efficiency.
• Multifunctional composites offer a solution by combining structural and electrical capabilities.
• Conventional conductors limit mass reduction in high-energy electric systems.

Purpose of the Study:

• To develop and characterize a novel glass-fiber-reinforced composite with aluminum fibers for electric energy transfer.
• To evaluate the combined electrical and mechanical properties and damage mechanisms of this multifunctional material.
• To assess its suitability for weight reduction in electric vehicles.

Main Methods:

• Fabrication of a hybrid composite with work-hardened and soft-annealed aluminum fibers.
• Static and fatigue mechanical load testing.
• Combined electrical-mechanical load testing.
• Characterization using light microscopy, thermal imaging, and resistance measurements.

Main Results:

• Approximately 10% aluminum fibers did not significantly alter fiber-parallel static properties.
• Transverse loading reduced tensile strength by 17% due to weak fiber bonding.
• Fiber-parallel fatigue strength was comparable to reference materials.
• Electrical resistance increased up to 60% under cyclic loading before rupture.
• Combined loads reduced fatigue life by 20% due to ohmic heating.
• Current carrying capacity up to 0.32 A/mm² was demonstrated.

Conclusions:

• The developed composite shows promise for electric energy transfer in weight-sensitive applications.
• Work-hardened aluminum fibers offer better mechanical performance than soft-annealed fibers.
• Understanding damage mechanisms under combined loads is crucial for design optimization.
• This research pioneers the investigation of such composites under combined electrical-mechanical stress.