The Dynamic Response And Damage Research Of Laminates According To The High Velocity Ice Impact

Compared with the titanium alloy,the carbon fiber composite fan blades has the advantages of lightweight,good anti-vibration performance,high damage tolerance capability,owing remarkable effects on reducing weight,enhancing the thrust-weight ratio and combustion efficiency,and will be the advanced development trend of the domestic aircraft engine.The high-speed rotating fan blades and other components of aero-engine during service are exposed to on-coming ice,birds,and other foreign objects impact,causing unpredictable damage,which may seriously threaten the normal operation of the aero-engine.Thus,the study on the dynamic response and damage characteristics of laminates according to the high-velocity ice impact is a crucial link to improve the fan blade design technology,which is of great significance to the research field of aero-engine.In this work,laminates made from T700/TDE-85 carbon fiber composites were considered as research objects,and were carried out different diameters of ice impact under various conditions,with different lay-ups,in terms of experiments and numerical simulations.The main contents and conclusions are as follows:?1?Ice with two different diameters?25.4 and 50 mm?were prepared.The impact experiments were conducted respectively on two kinds of lay-up([0/90]_4s,[0/45/90/-45]_2s)laminates with the same dimension?250×250×2mm³?,under three incident velocities.The macroscopic damage morphology and the internal damage map of laminates after the impact event was inspected visually and with ultrasonic C-scan separately.In addition,the macroscopic and internal damage status,and the damage categories were investigated and compared,under different working conditions.Combined with the MATLAB and the image recognition technology,failure rules of laminates were summarized with different parameters,such as the quality of ice,the incident velocity,and the ply angle.This work shows that the damage degree of composites increases with the energy of the projectile.In the case of the same impact energy,a smaller diameter ice can produce a larger failure area.?2?The numerical simulation method of ice impact laminates was investigated,based on the commercial finite element codes ANSYS/LS-DYNA.Moreover,Smooth Particle Hydrodynamics?SPH?was applied on the simulated hail ice,well describing the impact process and the mechanical behavior of ice projectile.Different models of the laminate were built,and the shell element model was chosen to simulate after the comparison.Introducing the MATLAB program,the numerical simulation results were analyzed and compared with the test results,and the deviation of the damage area is less than7.6%.Then,the validity and correctness of the simulation model of ice-impact laminates were verified.?3?In order to obtain the dynamic response study of laminates according to the ice impact was conducted to different factors of ice impact energy,the thickness and lay-up of laminates,combining with the above experimental results and numerical simulation models,in view of the macroscopic damage morphology,the damage area,energy absorption,effective stress and normal displacement,the anti-impact capabilities and the dynamic response rules of laminates were analyzed systematically,under different working conditions.Therefore,under the same impact conditions,the delamination of the laminate is the primary and the primary form of damage.The 45 degree ply can effectively provide the impact resistance,and the closer to the quasi-isotropic material,the stronger the impact resistance.Then,at the same quality of laminates,changing the angle of each ply can significantly improve the anti-ice impact ability of the laminate.In summary,the experiments and numerical simulations work on the ice impact laminates in this paper provides a strong basis for the design of laminates and the method research of verifying the properties of the actual composite structure in condition to anti-ice impact in the future.