Abstract
Several papers have been published in the past on the issue of decomposing a nonlinear system into subsystems for more efficient time integration. In this paper each body of a multi body system is considered as one subsystem. The subsystems (the bodies) are interacting via connection forces. The sources of such connection forces are constraints or directly applied forces. This contribution is restricted to constraint forces only. During a step which is named “body iteration”, those forces are considered as constant and the state of the system is computed for each body separately. This can be massively parallelized which can be an efficiency advantage in case of computational costly problems like the ones occurring in parameter estimation. During an “constraint update step” the constraints are evaluated based on the body’s current state. If the error is not small enough the interface forces are updated and the inner loop is executed once again until the error of the constraints is negligible. It turns out, that the constraints can be updated separately as well, which can be used again for parallel computing. In the paper, the theory will be outlined and implemented using an N body pendulum. Finally, the advantages and disadvantages of this approach are critically discussed.
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Abbreviations
- N:
-
Number of bodies
- M:
-
Number of constraints
- a, b:
-
Numbers of bodies which are involved in a certain constraint
- tn :
-
Denotes the time at time step n
- h:
-
Step size of time integration (h = tn−tn−1)
- α,β,γ:
-
HHT parameters
- q i :
-
State vector of body number i
- C j :
-
Constraint equation j
- P j :
-
Constraint force j
- a P j a,b :
-
Constraint force j acting on body a with involved bodies a and b
- λ j :
-
Lagrange multipliers for constraint j
- \( \underset{\bar{}}{{{C}}}^j_{{\!\!\!\mathbf{q}}^j}\) :
-
Constraint Jacobian for constraint j
- \( \underset{\bar{\mkern6mu}}{\mathbf{E}} \) :
-
Identity matrix
- \( \underset{\bar{\mkern6mu}}{\mathbf{\mathsf{M}}} \) :
-
Mass matrix
- Q i :
-
Forces acting on body i
- \( {\underset{\bar{\mkern6mu}}{\mathbf{J}}}_i \) :
-
Jacobian of body number i
- e i :
-
Residuum of equation of motion for body i
- c j :
-
Residuum of constraint equation j
- p j :
-
Residuum of constraint force j
References
Negrut D, Serban R, Mazhar H, Heyn T (2007) Parallel computing in multibody system dynamics: why, when and how. J Comput Nonlinear Dyn 9:12. doi:10.1115/1.4027313
van der Valk PLC, Rixon DJ (2014) Towards a parallel time integration for nonlinear systems. In: Allen M, Mayes R, Rixen D (eds) Dynamics of coupled structures. Proceedings of the 32nd IMAC, a conference and exposition on structural dynamics. Springer, vol 1, pp 135–145. ISBN: 978-3-319-04501-6
Sicklinger S, Belsky V, Engelmann B, Elmqvist H, Olsson H, Wüchner R, Bletzinger KU (2014) Interface Jacobian based co-simulation. Int J Numer Methods Eng 98:418–444. doi:10.1002/nme.4637
Negrut D, Rampalli R, Ottarsson G, Sajdak A (2007) On the implementation of the HHT method in the context of index 3 differential algebraic equations of multi body dynamics. J Comput Nonlinear Dyn 2(1):73–85. doi:10.1115/1.2389231
Scilab 5.5.1. www.scilab.com
Acknowledgement
We gratefully acknowledge the support from the Austrian funding agency FFG in the Coin-project ProtoFrame (project number 839074).
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© 2015 The Society for Experimental Mechanics, Inc.
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Witteveen, W. (2015). Body Wise Time Integration of Multi Body Dynamic Systems. In: Allemang, R. (eds) Special Topics in Structural Dynamics, Volume 6. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, Cham. https://doi.org/10.1007/978-3-319-15048-2_5
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DOI: https://doi.org/10.1007/978-3-319-15048-2_5
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-15047-5
Online ISBN: 978-3-319-15048-2
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