Material-structure Integrated Design Of Short Carbon Fiber Reinforced PEEK Composite Instrument Stand

Thermoplastic composites are used in the design of load-bearing structures for aircraft because of their high toughness,ease of processing,high specific strength and recyclability.As a thermoplastic composite matrix with high-temperature stability and corrosion resistance,poly（ether-ether-ketone）（PEEK）has become a research hotspot in recent years for the design of load-bearing structures for aircraft.However,the performance of traditional PEEK materials is still unable to meet the increasingly refined development of high-end equipment structural design needs,there is an urgent need to carry out PEEK-based composite material modification and structural optimization design to improve its service performance,for aircraft and other high-end equipment material system selection and structural design to provide strong support.In this paper,the design of graphene（GNP）,aminated carbon nanotubes（CNT-NH₂）and short carbon fibers（SCF）as reinforcement materials was carried out.The results of the material modification were verified through mechanical and damping performance tests,and the compression moulding process was optimized to produce a typical composite support.The details of the study are as follows.Firstly,nanomaterial-reinforced PEEK composites were prepared by the hot compression moulding process to investigate the effect of different types and contents of nanomaterials on the mechanical properties and dynamic mechanical properties of PEEK materials.The results show that both GNP and CNT-NH₂ enhance the stiffness and energy dissipation ability of PEEK,but weaken the strength and toughness of PEEK;compared with 5wt%GNP/PEEK composites,GNP/CNT-NH₂/PEEK composites with the same nano content have more comprehensive mechanical properties,and the higher the CNT-NH₂ content,the higher the strength and toughness.Following this,PEEK composites containing both short-cut carbon fibers（SCF）and nano-reinforcement terms were prepared by a compression moulding process to carry out a study of the effect of different short carbon fibers contents on the mechanical properties and dynamic mechanical properties of PEEK composites.The results show that at the macroscopic scale,SCF can substantially enhance the strength and modulus of PEEK composites,and improve the loss modulus and energy storage modulus in the full temperature domain;at the microscopic scale,CNT-NH₂ nanomaterials can further enhance the mechanical properties of SCF/PEEK composites.Finally,the designed PEEK composites are applied to the optimal design and preparation of typical scaffolds.The stent was optimized by an anisotropic Helmholtz density filtered skin reinforcement topology,and the optimal reinforcement configuration was obtained.The results show that the new configuration of the stent has improved the inherent frequency（24.1%increase in fundamental frequency）and stiffness（44.43%,51.12%and 75.46%increase in X,Y and Z directions respectively）in each order while reducing the weight by23.07%,thus achieving the lightweight design and fabrication of the typical stent structure.This paper carries out an integrated material-structure-manufacturing design and preparation of a typical bracket through material system design and structural optimization methods,which strongly supports the material system selection and structural design of high-end equipment.