Design, Preparation, Characterization And Evaluation Of Needle-punched/tufted Coupled Reinforced Composite

The aircraft radome is located at the head of the aircraft and integrates the functions of heat protection,bearing,corrosion resistance and wave transmission.The improvement of cruise speed and maneuverability of aircraft puts forward higher requirements for radome.The in-plane and interlaminar properties of existing needled structural composites are difficult to meet the service requirements in complex environments such as hypersonic flight.Based on this background,this paper studies the design,preparation,characterization and evaluation of needled/tufted coupling reinforced composites.A new structure of needled/tufted coupling reinforced preform is proposed.The tufted schemes of Mode I Interlaminar Fracture Toughness experiment,Mode II interlaminar shear experiment and tensile experiment are designed by Auto CAD software.the trajectory planning research is carried out,the robot executable program is compiled,the 3D needled/tufted coupling reinforced preform is prepared by robot,and the 3D needled/tufted coupling reinforced composite is prepared by RTM process.The Mode I Interlaminar Fracture Toughness of 3D needled/tufted coupling reinforced composites is studied.The results show that the interlaminar properties of3 D needled/tufted coupling reinforced composites were increased by 248.53%.When the tufted implantation amount and tufted interval are the same,the longer the tuft head,the greater the maximum failure load of Mode I Interlaminar Fracture Toughness.When the tufted interval and tufted head length are the same,the greater the tufted implantation,the greater the maximum failure load and the better the interlaminar performance.The Mode I Interlaminar Fracture Toughness double cohesive zone model is established.The simulated load displacement curve is consistent with the experimental load displacement curve,and the error rate of the maximum failure load is less than 2.9%.The Mode II Interlaminar Shear properties of 3D needled/tufted coupling reinforced composites are studied.The results show that the interlaminar shear properties of 3D needled/tufted coupling reinforced composites were increased by108.93%.When the same tufted implantation amount,the smaller the tufted interval,the greater the maximum failure load and the greater the interlaminar shear strength.When the tufted interval is the same,the greater the tufted implantation,the greater the maximum failure load and the greater the interlaminar shear strength.The Mode II Interlaminar Shear performance double cohesive zone model is established.The simulated load displacement curve is consistent with the experimental load displacement curve,and the error rate of the maximum failure load is less than 3.76%.The tensile properties of 3D needled/tufted coupling reinforced composites are studied.The results show that the in-plane tensile properties of 3D needled/tufted coupling reinforced composites were decreased by 10.98%,but the influence of tufted on the in-plane tensile properties can be reduced by changing the tufted parameters,among which the tufted parameters of 300 tex and tufted head length of 5mm have the least influence on the properties.