Study on anisotropic heat transfer and thermal damage in nanosecond pulsed laser processing of CFRP

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.

Section: Introductionmentioning

confidence: 99%

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

Li,

Shang,

Wan

et al. 2023

Assessment of continuous laser ablation model for lightweight quartz fiber reinforced phenolic composite

Yan,

Jin,

Pan

et al. 2024

A comprehensive investigation into the interaction between a continuous wave (CW) laser and lightweight quartz fiber reinforced phenolic (LQFRP) composite would provide valuable insights into the characteristics and performance of ablation. To simulate the CW laser ablation of LQFRP composite, a 2D symmetrical element model was developed, incorporating the heat conduction equation, resin pyrolysis mechanism, and deformed geometry module. This model was the first to examine the internal pyrolysis degree and gas flow field of LQFRP composite under CW laser irradiation, and its predictions were in reasonable agreement with experimental measurements. Additionally, the model was used to simulate CW laser ablation with varying spot sizes and power densities. The results revealed that during the laser ablation process, an internal high‐pressure zone formed on the side of the ablation hole. The volatilization of SiO2 was identified as the dominant dissipation mechanism for material removal. The width of the ablation hole was positively correlated with the laser spot size, while the depth of the ablation hole was positively correlated with the laser power density.Highlights The model first studied the internal pyrolysis degree and flow field of LQFRP composite under laser irradiation. The volatilization of SiO2 was identified as the dominant dissipation mechanism for material removal. An internal high‐pressure zone formed on the side of the ablation hole during the laser ablation process. The width of the ablation hole was positively correlated with the laser spot size, while the depth of the ablation hole was positively correlated with the laser power density.

Design, optimization, manufacture, and tests of CFRP hydraulic cylinder tube without metal liner: A bionic thorn‐tooth connection

Li,

Shang,

Wan

et al. 2024

Hydraulic cylinders are widely used in rudder surface control, landing gear retraction of aircraft. The aircraft could benefit a lot on weight reduction, by the application of the carbon fiber reinforced polymer (CFPR) on the hydraulic cylinder. The design, optimization, manufacture of the CFRP hydraulic cylinder tube without metal liner is systematically studied in this article. In terms of structure design, inspired by natural thorn plants, a bionic thorn‐tooth connection structure is designed to connect CFRP and the metal end. Then the theoretical design method of thorn‐tooth is proposed. It also provides a new solution for the generic technology of CFRP‐to‐metal connection. In terms of CFRP parameters design method, an accurate mechanical model of CFRP hydraulic tube is established, the influence law of CFRP parameters on mechanical properties is explored, and the optimization method of CFRP parameters adapted to new characteristics is proposed. In terms of the manufacturing process, the split manufacturing‐combined molding process with high precision and low cost is developed to fit the characteristics of CFRP hydraulic tube without metal liner. The prototype manufactured by the proposed method has a weight reduction ratio of 62.37% while maintaining performances compared to the original metal hydraulic cylinder tube. This research will bring significant performance gains and considerable economic and environmental benefits to aircrafts.Highlights The systematic study of CFRP hydraulic tube without metal liner is presented for weight reduction. The bionic thorn‐tooth connection and its parameter design method are proposed. The CFRP parameters design method of CFRP hydraulic tube is established. A manufacturing process adapted to CFRP hydraulic tube without metal liner is developed.