Low‐velocity impact and self‐healing behavior of <scp>CFRP</scp> laminates with poly(ethylene‐co‐methacrylic acid) filament reinforcement

In the high‐tech field, there is an urgent need for materials that possess thermal insulation, mechanical properties, and processing properties. One promising option is Carbon fiber reinforced thermoplastic composites (CFRTPs), which exhibit excellent characteristics such as light weight, high strength, and high temperature resistance. The effects and mechanisms of hollow glass beads (HGB) on the thermal insulation and mechanical properties of carbon fiber‐reinforced thermoplastic polyphthalazine ether sulfone ketone composites (CF/PPESK) were investigated. The introduction of 15 wt% HGB improved the material's thermal insulation performance by 32.74% perpendicular to the fiber direction and 44.95% parallel to the fiber direction. Furthermore, the addition of 3 wt% HGB increased the interlaminar shear strength, compression strength, and flexural strength by 21.34%, 17.49%, and 5.53%, respectively. Additionally, the dynamic mechanical analysis confirmed that the HGB/CF/PPESK composite has superior high‐temperature mechanical properties, which holds great promise for CFRTPs applications.Highlights Modification of CF/PPESK with HGB improved its thermal insulation properties. Analysis of the mechanism of CF/PPESK for thermal insulation performance. HGB improved the mechanical properties by delaying the expansion of microcracks. Agglomeration of HGB leads to a rapid rise in thermal insulation properties.

Thermal insulation and mechanical properties of carbon fiber‐reinforced thermoplastic polyphthalazine ether sulfone ketone composites reinforced by hollow glass beads

Feng,

Li,

Wang

et al. 2023

Low‐velocity impact response and post‐impact assessment of self‐healing composites with different stacking configurations of core–shell nanofibers

Cai,

Gan,

Chen

et al. 2023

This work investigates the low‐velocity impact (LVI) and self‐healing behavior of carbon fiber composite laminates interlaced with electrospun polyacrylonitrile core–shell nanofibers (PAN@CFRP). The main goal is to investigate the influence of different stacking configurations of core–shell nanofibers on the impact resistance and self‐healing properties of composite laminates. To achieve the purpose, three different stacking configurations were designed and tested alongside virgin specimens. The damage mechanism and self‐healing of laminates following LVI were determined using ultrasonic C‐scan and cross‐sectional microscopy examinations. At an impact energy of 14.1 J, the flexural strength of the post‐healing PAN‐3@CFRP specimen reached 95.0% of the initial value, whereas at an impact energy of 21.8 J, severe impact damage was observed in the laminates with different configurations. Among the laminates, the PAN‐1@CFRP specimen had the highest flexural strength after healing, which reached 80.1% of its pre‐impact strength. As observed, the impact resistance and self‐healing capacity of composites could be significantly enhanced by optimizing the distribution configuration of core–shell nanofibers for various impact energies.Highlights The introduction of electrospun core–shell nanofibers has not significantly compromised the mechanical properties of the composites, but rather enhanced their toughness. The addition of core–shell nanofibers significantly enhances the impact resistance of the composites and imparts excellent self‐healing properties to the material. The flexural strength of impact‐damaged specimens with different stacking configurations can be restored up to 95% of the undamaged specimen after repair treatment. Significantly improved impact resistance and self‐healing ability of laminates by optimizing the distribution configuration of core–shell nanofibers between composite layers.

Design, manufacture, and experiments of lightweight CFRP hydraulic cylinder tube without metal liner

Li,

Shang,

Wan

et al. 2023

Hydraulic cylinders are widely used in aircraft rudder surface control, landing gear retraction, flaps and speed brakes retraction, ground steering driving, and engine thrust reverser control. The huge weight of hydraulic cylinders severely limits the aircraft's potential for increased range, maneuverability, energy efficiency, and carrying capacity. To achieve the maximum weight reduction, the carbon fiber reinforced polymer (CFRP) hydraulic tube without a metal liner is designed in this paper. In response to the lack of a parameter calculation method for CFRP hydraulic tubes, the accurate calculation method is developed through mechanical modeling and analysis of parameter influence law. For the structure design challenges of connection, sealing, and friction of CFRP hydraulic tube without metal liner, we have proposed and verified the wave contour inlaid structure, three leak‐proof solutions of the connection interface, the leak‐proof structure of the wound CFRP body and the seal friction pair. For the difficulties of multi‐material and high‐precision molding, a new process of split manufacturing‐combined molding is developed to achieve high‐precision and low‐cost manufacturing. Finally, the prototype is manufactured and tested by the presented method, and its weight reduction ratio is 56.64% compared with the original metal hydraulic tube. This study has further matured the application of CFRP hydraulic tubes without metal liners and has great lightweight benefits in aircraft.Highlights CFRP hydraulic tube without metal liner is designed to reduce weight. An accurate calculation method of CFRP parameters is developed. Connection structure, leak‐proof structure, and seal friction pair are designed. The high‐precision and low‐cost molding process is innovatively proposed.