Stiffness of hybrid systems with and without pre-stressing

  • Received : 2019.06.29
  • Accepted : 2019.12.12
  • Published : 2020.04.25


Constructive merging of "basic" systems of different behavior creates hybrid systems. In doing so, the structural elements are grouped according to the behavior in carrying the load into a geometric order that provides sufficient load and structure functionality and optimization of the material consumption. Applicable in all materializations and logical geometric forms is a transparent system suitable for the optimization of load-bearing structures. Research by individual authors gave insight into suitable system constellations from the aspect of load capacity and the approximatemethod of estimating the participation of partialstiffnesswithin the rigidity ofthe hybrid system. The obtained terms will continue to be the basisfor our own research of the influence of variable parameters on the behavior of hybrid systemsformed of glued laminated girder and cable of different geometric shapes. Previous research has shown that by applying the strut-type hybrid systems can increase the load capacity and reduce the deformability ofthe free girder.The implemented parametric analysis pointsto the basic parameterin the behavior of these systems-the rigidity ofindividual elements and the overallstiffnessofthe system.The basic idea ofpre-stressing is that, in the load system or individual load-bearing element, prior to application of the exploitation load, artificially challenge the forcesthatshould optimize the finalsystembehaviorin the overall load. Pre-stressing is possible only if the supporting system orsystem's element possesssufficientstrength orstiffness, orreaction to the imposed forces of pre-stressing. In this paper will be presented own research of the relationship of partial stiffness of strut-type hybrid systemsofdifferentgeometric forms.Conducted parametric analysisofhybridsystemswithandwithoutpre-stressing, and on the example of the glulam-steel strut-type hybrid system under realistic conditions of change in the moisture content ofthe wooden girder,resulted in accurate expressions and diagramssuitable for application in practice.


  1. Ahn, J.H., Jung, C.Y. and Kim, S.H. (2010), "Evaluation on structural behaviors of prestressed composite beams using external prestressing member", Struct. Eng. Mech., 34(2), 247-275.
  2. Akbas, S.D. (2018), "Nonlinear thermal displacements of laminated composite beams", Coupl. Syst. Mech., 7(6), 691-705.
  3. Anshari, B.G. (2012), "Structural behaviour of glued laminated timber beams pre-stressed by compressed wood", Constr. Build. Mater., 29, 24-32.
  4. Anshari, B.G., Guan, Z.W. and Wang, Q.Y. (2017), "Modelling of Glulam beams pre-stressed by compressed wood", Compos. Struct., 165, 160-170.
  5. Anshari, B.G., Guan, Z.W., Kitamori, A., Jung, K., Hassel, I. and Komatsu, K. (2011), "Mechanical and moisture-dependent swelling properties of compressed Japanese cedar", Constr. Build. Mater., 25(4), 1718-1725.
  6. Buttner, O.H. (1985), Bauwerk Tragwerk Tragstruktur, Verlag fur Bauwesen, Berlin, Germany.
  7. Deam, B.F. (2008), "Experimental behavior of prestressed LVL-concrete composite beams", J. Struct. Eng., 134(5), 801-809.
  8. Dietz, M. (2008), "Das verhalten hybrider tragsrukturen unter einfluss der variation der system- und materijalsteifigkeiten", Doctoral Dissertation, Fakultat fur Architektur der Technischen Universitat Darmstadt, Germany.
  9. Giuntoli, G., Aguilar, J., Vazquez, M., Oller, S. and Houzeaux, G. (2019), "A FE2 multi-scale implementation for modeling composite materials on distributed architectures", Coupl. Syst. Mech., 8(2), 99-109.
  10. Hautefeuille, M., Colliat, J.B., Ibrahimbegovic, A., Matthies H.G. and Villon, P. (2012), "A multi-scale approach to model localized failure with softening", Comput. Struct., 94, 83-95.
  11. Ibrahimbegovic, A.H. (2013), "Linear instability or buckling problems for mechanical and coupled thermomechanical extreme conditions", Coupl. Syst. Mech., 2, 349-374.
  12. Kleinhanss, K. (1973), Weitgespannte Flachentragwerke-SFB 64, Werner-Verlag, Dusseldorf, Germany.
  13. Lavrencica, M. and Brank, B. (2018), "Failure analysis of ribbed cross-laminated timber plates", Coupl. Syst. Mech., 7(1), 79-93.
  14. Miljanovic, S. and Zlatar, M. (2015), "Theoretical and experimental research of external prestressed timber beams in variable moisture conditions", Coupl. Syst. Mech., 4(2), 191-209.
  15. Miljanovic, S. and Zlatar, M. (2016), Structures and Architecture: The Conceptual Design of Hybrid Structures - Theoretical and Experimental Research of External Prestressed Timber Beams, Taylor & Francis Group, London, Great Britain.
  16. Miljanovic, S. and Zlatar, M. (2017), "Selection of the optimal constellation of hybrid systems for pre-stressing", International journal MATEC Web of Conferences, 106, St. Petersburg, Russia.
  17. Rukavina, I., Ibrahimbegovic, A., Do, X.N. and Markovic, D. (2019) 'ED-FEM multi-scale computation procedure for localized failure", Coupl. Syst. Mech., 8(2), 111-127.
  18. Wagner, R., Gabriel, K. and Schlaich, J. (Schl 172/13-1), Hybride Tragwerke (Die logische Erfassung entwurfsrelevanter Faktoren: Geometrie-Funktion-Last-Auflager-Werkstoff-Form), Institut fur Massivbau, Universitat Stuttgart, Stuttgart, Germany.
  19. Yahyaei-Moayyed, M. (2011), "Creep response of glued-laminated beam reinforced with pre-stressed sub-laminated composite", Constr. Build. Mater., 25, 2495-2506.