Study On Material-structure-manufacture Integrated Design Strategy For PEEK-based Thermoplastic Composite Load-bearing Components

Fiber-reinforced thermoplastic composites have been widely used in aerospace,automotive,medical and other fields due to their advantages of high specific strength,high impact toughness,and recyclability.In recent years,the market share of thermoplastic composites has gradually increased,approaching 50% of the overall composites market.Polyether ether ketone(PEEK)has a high heat deflection temperature and excellent mechanical properties.It has been used in the design of load-bearing components in the design of aircraft in aerospace powerhouses.This paper mainly studies the integrated design of materials-structure-manufacturing for PEEK thermoplastic composite components.Firstly,hot-press forming technology is used to prepare pure PEEK materials.The influence of key process parameters such as forming temperature,time and pressure on the mechanical properties of hot-press forming PEEK materials is discussed,and a reasonable process of PEEK material hot-press preparation is determined.Furthermore,a one-time compression molding process was used to prepare satin-woven CF/PEEK composite materials with high mechanical properties.The experimental results showed that the satin-woven CF/PEEK composite exhibited differences in its tensile and compressive strength and stiffness.Stretching is more compressive.Based on the experimental results,the equivalent macroscopic elastic modulus of CF/PEEK composites was revised.Aiming at the three types of L-shaped,T-shaped and ?-shaped truss cross-sections,an efficient adaptive point-adding agent model optimization method is adopted to optimize the nonlinear buckling design of the three truss skinned truss shells.The optimal load-bearing capacity of the truss tube shell is: ?-shaped truss>T-shaped truss>L-shaped truss.In addition,a thermocompression molding process is used to prepare a thermoplastic composite beam with an optimized configuration and the molding quality is checked.A combination of experimental and numerical simulation methods is used to study the flexural performance of composite beams.The results show that the load-displacement rules in the bending test and simulation process are consistent,and they both show a typical bilinear mode.The maximum load test of the bending of the truss is close to the simulation.Finally,the axial compression test and numerical simulation of the bearing capacity of a typical thermoplastic composite truss-metal skin cylinder shell were carried out.The axial load-displacement curve of the test and simulation generally showed a linear increase and the stiffness gradually decreased,and the cylinder shell The failure mode is consistent.The numerical simulation shows that the bearing capacity of a typical skin truss shell(874.8KN)is basically consistent with the test result(809.8KN),with an error of 8%,which qualifies the requirement of engineering design.Compared with the metal skin truss structure,which verifies the rationality of the material-structure-manufacturing integrated design strategy proposed in this paper.The integrated material-structure-manufacturing design strategy for thermoplastic composite components proposed in this paper verifies the feasibility of the application of the advanced thermoplastic composite materials in the bearing section of aerospace equipment,and provides technical support for the next-generation aerospace material-structure design.