Dynamic analysis for vertical soft landing of reusable launch vehicle with landing strut flexibility

Yue, Shuai; Nie, Hong; Zhang, Ming; Huang, Mingyang; Zhu, He; Xu, Dafu

doi:10.1177/0954410017753209

Cited by 6 publications

(3 citation statements)

References 19 publications

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“…During the use of the aircraft landing gear, the lock mechanism will gradually wear during the unlocking process, which seriously affects the service life of the finger lock. 3 If the wear is within the specified range, the lock mechanism can maintain normal working conditions. If it exceeds the upper limit of wear, the friction force of the friction pair formed by the lock mechanism will rise sharply, 4 resulting in a retractable failure of the landing gear.…”

Section: Introductionmentioning

confidence: 99%

Wear analysis of finger locks with different design parameters for landing gear

Zhang

Nie

2020

Science Progress

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The finger lock in the retractable actuator of the landing gear will wear during repeated unlocking and locking. Therefore, the effects of six parameters including the material of the finger lock, the length of the finger lock, the diameter of the finger lock, the number of petals, and the angle of the fingertip on the unlocking force after 500 unlocking cycles are researched. Archard wear theory was performed to obtain the unlocking force after wear and the influence of six key parameters on the unlocking force in this paper. Then, wear experiment was designed and the effectiveness of model and the influence of six parameters were verified. The results show that the chamfers of the finger lock was most worn, causing the value of the axial unlocking force during the transition phase to increase, but it has little effect on the maximum unlocking axial force. The material of the lock has little effect on the axial force; the length, diameter and the number of petals are inversely proportional to the axial force, and the angle of the fingertip is proportional to the axial force. Using Archard method can effectively calculate the finger pattern wear of locks.

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Section: Introductionmentioning

confidence: 99%

Wear analysis of finger locks with different design parameters for landing gear

Zhang

Nie

2020

Science Progress

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“…The landing system is a critical subsystem of RLVs, the malfunction of which can cause recycle failure [3]. The design of RLV landing systems is quite difficult, because it requires high reusability, effective impact absorption, reliability, and heat resistance [4].…”

Section: Introductionmentioning

confidence: 99%

Parameterized Design and Dynamic Analysis of a Reusable Launch Vehicle Landing System with Semi-Active Control

et al. 2020

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Reusable launch vehicles (RLVs) are a solution for effective and economic transportation in future aerospace exploration. However, RLVs are limited to being used under simple landing conditions (small landing velocity and angle) due to their poor adaptability and the high rocket acceleration of current landing systems. In this paper, an adaptive RLV landing system with semi-active control is proposed. The proposed landing system can adjust the damping forces of primary strut dampers through semi-actively controlled currents in accordance with practical landing conditions. A landing dynamic model of the proposed landing system is built. According to the dynamic model, an light and effective RLV landing system is parametrically designed based on the response surface methodology. Dynamic simulations validate the proposed landing system under landing conditions including the highest rocket acceleration and the greatest damper compressions. The simulation results show that the proposed landing system with semi-active control has better landing performance than current landing systems that use passive liquid or liquid–honeycomb dampers. Additionally, the flexibility and friction of the structure are discussed in the simulations. Compared to rigid models, flexible models decrease rocket acceleration by 51% and 54% at the touch down moments under these two landing conditions, respectively. The friction increases rocket acceleration by less than 1%. However, both flexibility and friction have little influence on the distance between the rocket and ground, or the compression strokes of the dampers.

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“…After several successful industry-funded recovery tests, the vertical landing RLV has attracted public attention. Among all subsystems of vertical landing RLV, the landing gear system is one of the most important systems because its malfunction can lead to the failure of the entire mission [1]. Due to the uncertainties in the initial landing conditions and relatively high gravity center of the RLVs, the dampers are necessary and essential part in the landing gear system to reduce the landing impact and improve landing stability.…”

Section: Introductionmentioning

confidence: 99%

Liquid spring damper for vertical landing Reusable Launch Vehicle under impact conditions

Yue

Titurus

Nie

et al. 2019

Mechanical Systems and Signal Processing

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This research presents the modelling, experimental validation and analysis of the liquid spring damper under impact conditions during the symmetric vertical soft landing of a Reusable Launch Vehicle. A new nonlinear lumped parameter hydraulic model of a liquid spring damper is first established including the variable liquid bulk modulus, entrapped air, flow inertial effects and cavitation phenomena. Then, a simplified nonlinear model of the scaled Reusable Launch Vehicle test prototype isproposed. This dynamic model, which consists of a three degree-of-freedom main body and a single landing leg assembly with one liquid spring damper, is studied under impact conditions. The experimental prototype with the four nominally identical landing legs is experimentally studied. First, the quasi-static spring damper tests are conducted to identify the compressibility and friction parameters.Then, the Reusable Launch Vehicle prototype drop tests are performed to identify the liquid flow parameters, to validate the damper impact response characteristics and to evaluate the full prototype model through its comparison with the experimental data. It is found that a very good match can be established between the predicted and measured quasi-static damper responses. The local damper predictions also indicate good correlation with the impact test results. The landing prototype simulations indicate qualitatively correct predictions with the main observed discrepancies attributed to the simplified and potentially excessively stiff nature of the prototype model.

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Dynamic analysis for vertical soft landing of reusable launch vehicle with landing strut flexibility

Cited by 6 publications

References 19 publications

Wear analysis of finger locks with different design parameters for landing gear

Wear analysis of finger locks with different design parameters for landing gear

Parameterized Design and Dynamic Analysis of a Reusable Launch Vehicle Landing System with Semi-Active Control

Liquid spring damper for vertical landing Reusable Launch Vehicle under impact conditions

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