Abstract
An efficient method for computing responses of large and complex structures is Dynamic Substructuring. In Dynamic Substructuring methods one decomposes the large and complex structure in several substructures, which are individually modeled. The obtained knowledge of individual subsystems, allows one to create an efficient and compact model of the global system. When the forces can not be measured in the substructure from where the excitation originates, it can however be characterized on the interface either as a blocked force or a free interface motion. In this contribution the idea of blocked forces and equivalent free interface displacement, originally developed in the frequency domain, is extended to the time domain. The method transforms internal force and displacement excitation of linear substructures, into a set of equivalent forces or displacements on the boundary degrees of freedom. The method has a number of advantages; Firstly, it simplifies the reduction of force loaded structures, as it requires no special treatment for the forces acting on the internal parts of the structure. Also, it allows for groups working on different components to couple the dynamics by only sharing the interface excitations and (reduced) component models. Finally, it should be noted that using time-domain approaches compared tot he previously published frequency-domain approaches for equivalent forces and displacements, allows also considering coupling with non-linear receiving substructures. It will be analytically proven that for all other substructures the exact same response will be found. In addition it will be shown how to recover the correct response for the force loaded substructure in the case the internal forces are known. The methods will be demonstrated using the model of an offshore wind turbine that is loaded with (linearized) wave forces on its support structure.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Craig R (2000) Coupling of substructures for dynamic analyses – an overview. In: Proceedings of AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics, and materials conference and exhibit, April 2000, pp 1573–1584
de Klerk D, Rixen DJ (2010) Component transfer path analysis method with compensation for test bench dynamics. Mech Syst Signal Proces 24:1693–1710
de Klerk D, Rixen D, Voormeeren S (2008) General framework for dynamic substructuring: history, review and classification of techniques. AIAA J 46(5):1169–1181
de Vries W, Vemula NK, Passon P, Fischer T, Kaufer D, Matha D, Schmidt B, Vorpahl F (2011) Final report WP 4.2 - support structure concepts for deep water sites. Tech. rep., Project UpWind
Dickens JM, Stroeve A (2000) Modal truncation vectors for reduced dynamic substructure models. In: Structures, structural dynamics and material conference (Atlanta, 3–6 April 2000). 41st AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics, and materials conference and exhibit. AIAA-2000-1578
Jonkman J, Butterfield S, Musial W, Scott G (2009) Definition of a 5-MW reference wind turbine for offshore system development. Tech. rep., National Renewables Energy Laboratory
Morison JR, O’Brien MP, Johnson JW, Schaaf SA (1950) The force exerted by surface waves on piles. Petroleum Trans (American Institute of Mining Engineers) 189:149–154
Newmark N (1959) A method of computation for structural dynamics. In: Proceedings of the American society of civil engineers. Journal of the Engineering Mechanics Division (1959), pp 67–94
Nortier BP, Voormeeren SN, Rixen DJ (2012) Application of residual vectors to superelement modeling of an offshore wind turbine foundation. In: Proceedings of the SEM IMAC XXX conference, Jacksonville, FL, USA, 30 Jan–2 Feb 2012
Rixen DJ (2004) A dual Craig-Bampton method for dynamic substructuring. J Comput Appl Math 168:383–391
Rixen DJ, van der Valk PLC (XXXX) An impulse based substructuring approach for impact analysis and load case simulations. J Sound Vib
Rixen DJ, Boogaard MA, van Schothorst G, van der Poel GW (XXXX) Blocked forces and free displacements approaches for vibration transmission analysis. Mech Syst Signal Process (submitted)
van der Valk PLC, Rixen DJ (2012) Impulse based substructuring for coupling offshore structures and wind turbines in aero-elastic simulations. In: Proceedings of 53rd AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics and materials conference, Honolulu, HI, 23–26 April 2012
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 The Society for Experimental Mechanics, Inc.
About this paper
Cite this paper
van der Valk, P.L.C., Rixen, D.J. (2014). Substituting Internal Forces for Blocked Forces or Free Interface Displacements in Substructured Simulations. In: Mayes, R., Rixen, D., Allen, M. (eds) Topics in Experimental Dynamic Substructuring, Volume 2. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-6540-9_8
Download citation
DOI: https://doi.org/10.1007/978-1-4614-6540-9_8
Published:
Publisher Name: Springer, New York, NY
Print ISBN: 978-1-4614-6539-3
Online ISBN: 978-1-4614-6540-9
eBook Packages: EngineeringEngineering (R0)