This research evaluates the presence of buckling modes in built-up columns made from pultruded fiber reinforced polymer (FRP) profiles when flexural instability is coupled with torsional instability. This phenomenon is already well known in the field of steel construction and is tested and emphasized with the use of thin walled open cross sections of pultruded FRP materials in testing to analyze the effects of local buckling due to FRP’s orthotropy and high deformability. Also through previous tests on columns made by singular “C” shapes that create the built-up columns tested, the study presents the confidence between experimental results for the pultruded FRP built-up columns and the available formulas for calculating the expected buckling interactions. The investigation shows that torsional-flexural buckling is confirmed but is also combined with a local buckling that first influences the buckling interactions. From a practical application point of view, the study examines a comparison between experimental and formulation characterization of buckling analysis with open cross sections assumed as equivalent to the built-up cross sections. The ratio between the different critical loads and their chronology to collapse is described.
Russo S and Adilardi A. Innovative design approach to a GFRP pedestrian bridge: Structural aspects, engineering optimization and maintenance. In: Proceedings of The fifth international conference on bridge maintenance, safety and management. Philadelphia, USA, 11–15 July 2010, pp.2455–2459. ISBN: 9780415877862.
2.
Boscato G and Russo S. On mechanical performance of different type of FRP beams as reinforcement of pedestrian bridge, bridge maintenance, safety management, health monitoring and informatics. In: Proceedings of the fourth international conference on bridge maintenance, safety and management, Seoul, Korea, 13–17 July 2008. ISBN: 9780415468442.
3.
RussoS. Experimental and finite element analysis of a very large pultruded FRP structure subjected to free vibration. Compos Struct2012; 94: 1097–1105.
4.
BoscatoGDal CinARussoS. Structural health monitoring of historic damaged churches. Adv Mater Res2014; 838–841: 2071–2078.
5.
Boscato G, Pizzolato M, Russo S, et al. Seismic behavior of a complex historical church in L'Aquila. Int J Architect Heritage 2012; 8: 718–757. ISSN: 1558-3066. DOI: 10.1080/15583058.2012.736013.
6.
Russo S. On the monitoring of historic Anime Sante church damaged by earthquake in L’Aquila. Structural control and health monitoring 2012. ISSN: 1545-2263, DOI: 10.1002/stc.1531.
7.
Zureick A and Scott D. Short-term behavior and design of fiber-reinforced polymeric slender members under axial load compression. J Compos Construct 1997; 1: 140–149.
8.
Godoy LA, Barbero EJ and Raftoyiannis I. Interactive buckling analysis of fiber reinforced thin walled columns. J Compos Mater 1995; 29: 591–613.
9.
BarberoEJDedeEKJonesS. Experimental verification of buckling mode interaction in intermediate-length composite columns. Int J Solid Struct2000; 37: 3919–3934.
10.
National Research Council of Italy, DT CNR 205/2007, Technical recommendations, Guide for the Design and Construction of Structures made of FRP pultruded elements, Rome, October 2008.
11.
Bank LC. Composites for construction, structural design with FRP materials. New Jersey, USA: John Wiley and Sons, Inc., 2006.
12.
Agarwal BD and Broutman LJ. Analysis and performance of fiber composites. 2nd ed., New York, USA: Whiley InterScience, 1990.
13.
Boscato G, Mottram JT and Russo S. Dynamic response of a sheet pile of fiber reinforced polymer for waterfront barriers. J Compos Construct 2011. ISSN: 1090-0268, DOI: 10.1061/(ASCE)CC.1943-5614.0000231.
14.
BoscatoGRussoS. Free vibrations of pultruded FRP elements: mechanical characterization, analysis, and applications. J Compos Construct2009; 13: 565–574.
15.
BoscatoGRussoS. Free vibrations of a pultruded GFRP frame with different rotational stiffness of bolted joints. Mech Compos Mater2013; 48: 655–668.
16.
Boscato G and Russo S. Dissipative capacity of FRP spatial pultruded structure. Compos Struct 2014; 113: 339–353. DOI: 10.1016/j.compstruct.2014.03.036.
17.
Russo S. Damage assessment of GFRP pultruded structural elements. Compos Struct ISSN: 0263-8223. DOI: 10.1016/j.compstruct.2012.09.014.
18.
Di TommasoARussoS. Shape influence in buckling of GFRP pultruded columns. Mech Compos Mater2003; 39/4: 329–340.
19.
Boscato G, Casalegno C, Russo S, et al. Buckling of GFRP pultruded built-up columns. In: Advanced composites in construction (ACIC) Conference, Belfast, 10–12 September 2013, pp.178–189.
20.
Boscato G, Casalegno C, Russo S, et al. Buckling of built-up columns of pultruded fiber-reinforced polymer C-sections. J Compos Construct 2014; 18(4): 04013050.
BoscatoGCasalegnoCRussoS. Performance of built-up columns made by pultruded FRP material. Compos Struct2015; 121: 46–63.
23.
Timoshenko SP and Gere JM. Theory of elastic stability. 2nd ed. New York: Mc Graw Hill, 1961.
24.
Shafer BW and Adamy S. Buckling analysis of cold-formed steel members using CUFSM: conventional and constrained finite strip methods. In: Proc. of the eighteenth int. sp. conf. on cold-formed steel structures, Orlando, Florida, 26–27 October 2006, pp.39–54.
25.
Moen C and Shafer BW. Stability of cold-formed steel columns with holes. In: Camotin et al. (ed.) Proc. of the Int. colloquium on stability and ductility of steel structures. Lisbon, Portugal, Vol. 2, 2006, pp.697--704.
26.
Shafer BW and Pekoz T. Direct strength prediction of cold-formed steel members using numerical elastic buckling solutions. In: Proc. of the fourteenth int. spec. conf. on cold-formed steel structures, S.Louis, Missouri (MO), 15 October 1998, pp.69–76.
27.
MoenCShaferBW. Direct strength design for cold-formed steel members with perforations progress report No.1, Washington, DC: American Iron and Steel Institute, 2006.
YangDHancockGJ. Compression tests of high strength steel; channel columns with interaction between local and distortional buckling. J Struct Eng2004; 130: 1954–1963.
30.
Russo S and Adilardi A. Innovative design approach to a GFRP pedestrian Bridge: Structural aspects, engineering optimization and maintenance. In: Proc. of the fifth int. conf. on bridge maintenance, safety and management, Philadelphia, USA, 11–15 July 2010, pp.2455–2459.
31.
Boscato G and Russo S. Proposal of the concrete-GFRP interaction models. Compos: Mech, Computat, Appl J, Begell House, 2014, pp.273–303. DOI: 10.1615/CompMechComputAppllntJ.v5.i4.20.
32.
KollarLP. Local buckling of fiber reinforced plastic composite structural members with open and closed cross section. J Struct Eng, ASCE2003; 129: 1503–1513.
33.
Kollar LP and Springer GS. Mechanics of composites strcutures. Cambridge (UK): Cambridge University Press.
34.
Steel construction manual, 13th ed. American Inst of Steel Constr., AISC, Canada and USA: Thomson Reuters, 1 February 2006.
35.
Selvaray M, Kulkarni SM and Ramesh Babu R. Behavioral analysis of built-up transmission line tower from FRP pultruded sections. IJETAE 2012; 2(9): 39–47.
36.
Mohamed Elmady G. Buckling of built-up columns. PhD Thesis, University of Windsor, 1997.
37.
Gjelsvik A. Buckling of built-up columns with or without stay plates. J Eng Mech 1990; 116(5): 1142–1159.
38.
Russo S. Performance of a PFRP structure covering a historic building struck by an earthquake. In: Proceedings of the 5th international conference on advanced composites in construction (ACIC), Warwick, UK, 6–8 September 2011, pp.51–57.
