In this paper, a stiffening design imitating the bamboo node is proposed for weight reduction of the long composite pipe beam subjected to bending load. The distribution of bamboo nodes can efficiently suppress the ovalization of the section, thus significantly improving the bending resistance of the bamboo. Based on this principle, ring stiffeners are proposed to be fixed to the pipe beam, making the long beam equivalent to the combination of a series of short pipes that suffered less section ovalization. A database of the optimal laminate orientations for different normalized lengths is obtained through optimizations, where the discreteness of the ply count is considered. Based on this database, weight optimizations are conducted, and the optimal designs of beams with and without stiffeners are obtained and compared. The comparison results show that the proposed bamboo-like stiffened beam not only regains a near-linear load–displacement relationship, but also reduces the weight by up to 16% under the same buckling load. In addition, it is found that for the pipe beams with radius-to-thickness ratios of more than 18, increasing the radius leads to a decrease in elastic buckling resistance when the weight remains a constant, which is opposite to the design for strength and stiffness. The model and database developed in this paper can provide a reference for weight reduction design and weight estimation for composite pipe beams.

Ski-jump ramp is of great significance to improve the takeoff performance of carrier based aircraft. However, the ski-jump ramp produces stronger air-wake than that of the flat deck, resulting in unstable air flow above the deck and near the glide line, that can affect the takeoff and landing safety of the carrier based aircraft. Using the DES turbulence model mixed with RANS and LES, CFD computations were performed to simulate air wakes of the flat and ski-jump decks. The comparison shows that there is a huge separation bubble behind the ski-jump ramp, which has a great impact on the air flow on the upper surface of the deck and near the landing glide line, leading to the reduction of the x-velocity of the wind over the deck as well as the increase of the takeoff and landing speeds of the carrier aircraft. Meanwhile, the amplitude of velocity fluctuations is also increased by the separation bubble, and this brings difficulty in accurate track control of the carrier aircraft. In order to effectively suppress the air wake caused by the ski-jump ramp, the control based on cylindrical vortex generators (CVG) has been proposed. Due to the existence of CVG, the flow around the upper surface of the ski-jump ramp is changed from separated flow to attached flow, and it greatly reduces the fluctuation amplitude of the air flow on the upper surface of the ski-jump deck. Compared to the case without CVG, the x-velocity of the wind over the deck is increased, and the PSD of the wind velocity fluctuation is reduced by 20 to 40 dB, restored to the same level as that of the flat deck, thus effectively improving the take-off and landing safety of the carrier aircraft.