Research On Ballistic Properties Of Bionic Arrangement Structural Fiber Reinforced Composites

In the modern battlefield,with increasing lethality of weapons,which puts forward higher requirements for ballistic properties of individual protective equipment.Fiber reinforced composites equipment combine the advantages of excellent ballistic properties and lightweight so have become a key choice for protective materials.In order to design fiber reinforced composites with excellent ballistic properties,based on the cuticle microstructure of lobster claw,bionic fiber reinforced composites were prepared by aramid fiber prepreg and carbon fiber prepreg and the improvement of gradient helical structure and rigid-flexible coupling structure on ballistic properties of fiber reinforced composites was explored.The specific contents of this paper are as follows:1.Based on gradient Bouligand structure in the exocuticle and endocuticle of lobster claw,the structures of aramid fiber reinforced composites were optimized to lobster-inspired gradient helical structure and the ballistic test and the ballistic finite element simulation were carried out.The lobster-inspired gradient helical structure,which comprises linear helical and linear helical combination,has improved the ballistic properties of fiber reinforced composites.The V50 value is 635 m/s,which is slightly higher than the V50 value(633 m/s)of traditional structural fiber reinforced composite samples.The absorbed energy value of unit area density and the absorbed energy value of unit thickness have been increased by 0.65% and 5.28%,respectively.The helical structure mainly plays an important role in the bullet shock behavior at the late stage of the impact process.The propagation direction of stress between fiber layer changes based on helical structure along the fiber direction,and cracks are easy to occur at the stress concentration.The deflection of the crack propagation path makes more absorbed energy and improve the ballistic properties of fiber reinforced composites.However,the helical structure causes large in-plane damage,resulting in serious damage appearance.2.Based on the characteristic of rigid-flexible coupling in the cuticle of lobster claw,the structures of aramid fiber and carbon fiber interlayer hybrid reinforced composites were optimized to lobster-inspired rigid-flexible coupling structure and the ballistic test and the ballistic finite element simulation were carried out.With C: K = 1:2.6,carbon fiber as the front face and aramid fiber as the back face,lobster-inspired rigid-flexible coupling structure fiber reinforced composites have excellent ballistic properties.The V50 value is 647 m/s,which is 2.21% higher than that of traditional structural fiber reinforced composite samples.The absorbed energy value of unit area density and the absorbed energy value of unit thickness have been increased by 5.36%and 14.56%,respectively.The results of dynamic and static mechanical experiments show that the carbon fiber reinforced composites sample has high compressive strength and small peak strain at the high strain rates,while the aramid fiber reinforced composites sample has high dynamic and static tensile strength.At the early stage of the impact process,carbon fiber reinforced composites with excellent dynamic compressive properties have achieved small deformation and strong absorption near the front face.At the late stage of the impact process,aramid fiber reinforced composites with excellent dynamic tensile properties have absorbed large impact energy when has tension failure and delamination.The lobster-inspired rigid-flexible coupling structure has improved ballistic properties of fiber reinforced composites and the bio-inspired structural fiber reinforced composites has slight damage appearance.