Proceedings home preface contents authors keywords copyright reference ©2012 Civil-Comp Ltd				Paper 4 Finite Element Analysis of Failure Modes for Cellular Steel Beams B. Dervinis and A.K. Kvedaras Vilnius Gediminas Technical University, Lithuania Keywords: cellular steel beam, rational section's dimensions, non-linear analysis, applied software, finite element analysis. full paper (pdf) - reference Nowdays cellular beams are widely used in the building industry. The range of applications and advantages of such beams are described in this paper. This paper deals with the numerical non-linear analysis of the behaviour of cellular steel beams taking into account the geometrical and physical nonlinearities. In this paper six failure modes of cellular beams are overviewed and investigated using the finite element method. Deformed shapes and stress distributions of the beams are presented graphically for each failure mode. Characteristic signs of each failure mode are overviewed. The influence of beam dimensions, supporting and loading conditions are analysed. It is found, that the material of the beams is used most efficiently when the upper flange of the beam is restrained out of plane and the beam fails because of a flexural mechanism. The calculations also showed that for beams longer than six to seven metres the main failure mode is exceeds the ultimate deflection. Nowadays, analysis of steel beams with web openings is well investigated in [1,2,3] and others. Therefore, there is no difficulty to obtain and verify the load bearing capacity for a member with known dimensions. However, it might be difficult to obtain a section with rationally designed dimensions for a known value of applied loading. Therefore, it is very important to develop a method for selecting the rational parameters of cellular beams. Rational use of material of load bearing structures may save significant money and resources. So, the concept of the selection of rational sectional parameters for the steel beams with the multiple circular openings, based on data from the numerical analyses, is proposed. Two practical examples were solved presenting how the method of selection of the beams with the rational cross-sectional dimensions as well. References 1 J.D. Megharief, "Behaviour of composite castellated beams", MSc Thesis, McGill University, Montreal, 1997. 2 A. Mohebkhah, "The moment-gradient factor in lateral-torsional buckling on inelastic castellated beams", Journal of Constructional Steel Research. 60(10), 1481-1494, 2004. 3 T. Zirakian, H. Showkati, "Distortional buckling of castellated beams", Journal of Constructional Steel Research, 62(9), 863-871, 2006.