FINITE ELEMENT ANALYSIS ON LATERAL TORSIONAL BUCKLING BEHAVIOUR OF I-BEAM WITH WEB OPENING

Lateral torsional buckling may occur in an unrestrained beam. A beam is considered to be unrestrained when its compression flange is free to laterally rotate and laterally displace. In this paper, the finite element analysis is used to investigate the lateral torsional buckling behavior of I-beam with and without web opening. The analysis considers a wide range of practical distances between two openings as well as, various shapes and sizes of web opening. Analysis results show that the size of web opening has slightly effect on the buckling moment resistance. Furthermore, five shapes and three sizes of opening with 1.1m section length were used to find the optimum size and shapes of opening. It was concluded that, the optimum size is 0.5D due to the high values of the buckling moment compared with 0.6D and 0.7D. Meanwhile, model 2 is classified as the optimum model because the value of buckling moment is higher than model 1. It was noted that C-hexagon has the highest buckling moment compared to other web opening shapes. Besides that, the differences in buckling moment values decrease when the opening becomes larger in size such as square opening. However, I-beam without web opening has the highest buckling moments resistance compared to C-hexagon.