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A hybrid variational method for multibody dynamics
Author(s) -
Chung Shu,
Haug Edward J.
Publication year - 1993
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.1620360106
Subject(s) - multibody system , equations of motion , mathematics , constraint (computer aided design) , converse , mechanical system , computational complexity theory , motion (physics) , lagrange multiplier , chain (unit) , mathematical analysis , mathematical optimization , algorithm , computer science , classical mechanics , geometry , physics , astronomy , artificial intelligence
This paper presents a hybrid variational method to minimize computational effort in forming and solving the equations of motion for broad classes of rigid multibody mechanical systems. The hybrid method combines the O(n) and O(n 3 ) recursive variational methods for forming the equations of motion in terms of joint relative co‐ordinates. While the O(n 3 ) method is more efficient than the O(n) method for systems with short chains and decoupled loops, the converse is true when the number of bodies in chains is large. The computational complexity of the O(n 3 ) and O(n) methods in forming and solving the equations of motion is analysed as a function of the numbers of bodies, decoupled loops, joints, cut joints, cut‐joint constraint equations and force elements. Based on complexity estimates, the method presented in this paper uses either the O(n) or O(n 3 ) variational method to formulate the equations of motion for each open chain and decoupled loop in the system, to minimize the computational effort.