Acta Mechanica Solida Sinica

, Volume 29, Issue 6, pp 631–641

# Structure-Preserving Analysis on Folding and Unfolding Process of Undercarriage

• Weipeng Hu
• Mingzhe Song
• Zichen Deng
• Xindong Wang
• Zhiwei Xiong
Article

## Abstract

The main idea of the structure-preserving method is to preserve the intrinsic geometric properties of the continuous system as much as possible in numerical algorithm design. The geometric constraint in the multi-body systems, one of the difficulties in the numerical methods that are proposed for the multi-body systems, can also be regarded as a geometric property of the multi-body systems. Based on this idea, the symplectic precise integration method is applied in this paper to analyze the kinematics problem of folding and unfolding process of nose undercarriage. The Lagrange governing equation is established for the folding and unfolding process of nose undercarriage with the generalized defined displacements firstly. And then, the constrained Hamiltonian canonical form is derived from the Lagrange governing equation based on the Hamiltonian variational principle. Finally, the symplectic precise integration scheme is used to simulate the kinematics process of nose undercarriage during folding and unfolding described by the constrained Hamiltonian canonical formulation. From the numerical results, it can be concluded that the geometric constraint of the undercarriage system can be preserved well during the numerical simulation on the folding and unfolding process of undercarriage using the symplectic precise integration method.

## Key Words

structure-preserving symplectic precise integration nose undercarriage constraint default

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© The Chinese Society of Theoretical and Applied Mechanics and Technology 2016

## Authors and Affiliations

• Weipeng Hu
• 1
• 2
• 3
• Mingzhe Song
• 1
• Zichen Deng
• 1
• 2
• Xindong Wang
• 1
• Zhiwei Xiong
• 4
1. 1.School of Mechanics, Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’anChina
2. 2.State Key Laboratory of Structural Analysis of Industrial EquipmentDalian University of TechnologyDalianChina
3. 3.State Key Laboratory of Solidification ProcessingNorthwestern Polytechnical University710072China
4. 4.School of Mechanical and Electronic EngineeringWuhan University of TechnologyWuhanChina