Research On Impact Resistance Of Basalt Fiber/steel Hybrid Laminate

The lightweight design of ship is the main character to improve the overall performance of the ship,so that it can obtain a higher sailing speed under the same power,improve the maneuverability and flexibility of the ship,and have a strong resistance strike ability.The application of lightweight composite materials on ships is an important part of the lightweight design of ships.Fiber-reinforced composite materials has poor impact resistance,even though it have high specific strength and high specific stiffness.However,metal materials have a fast crack growth rate and low fatigue life.In order to overcome the shortcomings of both composite materials and metal materials,fiber metal laminates(Fiber Metal Laminates/FMLs)came into being.Traditional FMLs are severely corroded by seawater and hardly applied to ships.A basalt fiber-steel hybrid laminate for ship superstructures was designed and prepared.Furthermore,the static mechanical properties,low-speed impact performance and ballistic impact performance was obtained,under various hybrid laminates by experimental method.The demage and failure features were analysised by numerical simulation during the ballistic impact process.The main works are as follows:(1)The various properties of FMLs component materials were compared and analyzed.The basalt fiber and 304 stainless steel suitable for marine applications are selected as the component materials of the hybrid laminate.The surface of 304 steel was sandblasted,and the microscope image results showed that a uniform rough surface was produced after sandblasting,and sandblasting had a significant impact on the interface strength,which increased the shear strength of the interface by 42.8%.(2)Research on static mechanical properties of hybrid laminates with the same thickness of three different layers structures(2/1,3/2,4/3).The tensile results show that the fracture strain of the hybrid laminate is less than or equal to the minimum fracture strain of the component materials,the 2/1 structure has the highest tensile strength,the 3/2 structure is slightly lower,and the 3/2 structure has a stepped tensile fracture process.Both compression and bending experiments show that the 2/1 structure has the highest compression and bending strength,followed by the 3/2 structure,and the 4/3 structure has the lowest strength.(3)A drop hammer impact experiment was carried out on hybrid laminates with the same thickness and different ply structures,the effects of layer structure,impact energy and hammer shape on the low-velocity impact performance of hybrid laminates were studied.The results show that under the action of a flat impactor,the 4/3 ply structure has the highest energy absorption rate at low energy,while the 2/1 ply structure has the highest energy absorption rate at high energy.Under the action of the hemispherical impactor,the 3/2 ply structure has the highest energy absorption rate at low energy,but the lowest at high energy.The 4/3 ply structure always has the highest energy absorption rate under the action of the conical impactor.Under the same energy impact,the energy absorption gap of the three impactor decreases with the increase of the number of metal layers in the structure.At the same time under the different impactor shape,it can be concluded that the sharper impactor generates longer contact duration,lower peak impact force and lower initial slope of impact load curve.(4)The ballistic impact experiment of the hybrid laminate was carried out,and the influence of the layer structure,fiber volume fraction,structure surface density,and penetration angle on the ballistic performance was studied.The results show that the ballistic performance of the hybrid laminate with the 3/2 ply structure is better than that of the 2/1 ply structure,and2/1 ply structure is better than the 4/3 ply structure.In the 3/2 structure,with the increase of the fiber volume fraction in the structure,the ballistic performance decreases.With the increase of the surface density of the structure,the energy absorption per unit area density increases after the projectile penetrates the target plate.Oblique penetration test results show that the greater the penetration angle,the more energy the projectile loses after penetrating the target.(5)Numerical simulation analysis of ballistic impact test process is carried out.The simulation results and experimental results show good consistency in terms of ballistic limit,damage and failure mode,and residue speed after penetration.The ballistic limit error of simulation and test is 7.7%,and the simulation truly restores the penetration process.The effects of the distance between two projectiles and the time interval of successive penetration on the Resistance to penetration of the target plate are analyzed.The results show that when the distance between the two projectiles is greater than 1.5 times the projectile radius,the impact of the projectile distance on the Resistance to penetration of the target is negligible.After projectile 1 penetrates the target plate first,the Resistance to penetration of the target plate increases before the lamination delamination expansion,and decreases after the lamination delamination expansion.This research provides a strong reference for the design and application of basalt fibersteel hybrid laminates in the lightweight of ships.In engineering applications,it is recommended to use a hybrid laminate with a 3/2 ply structure,which can effectively reduce the peak impact load during low speed impact and has better penetration resistance during high speed impact.