Castellated steel beams are those members which are made from hot rolled steel I-section firstly by cutting the web in zigzag pattern and rejoining the two halves by welding together to form a hexagonal castellated beam such that the depth of section will be increased. Generally, the openings made in the web are with hexagonal shape; however, octagonal shape of web openings is typically obtained by providing spacer plate which is utilized to increase the depth of beam. Nowadays, using castellated beams in building construction becomes very popular because of their useful functions such as ease of service provision, strength and low cost. This study focuses on improving the behavior of hexagonal and octagonal castellated beam with spacer plate. The ultimate strength of the original (parent) I- section beam increases due to the increasing its depth. The increment of castellated beam depth; however, leads to post buckling in its web and to many other modes of failure when these beams are subjected for loading. Hexagonal and octagonal castellated beams which are fabricated using parent I-section (IPN140) are analyzed using finite element model (FEM).The analysis results revealed that using ring stiffeners around edge of holes contributes effectively in strengthening the web. It was found that using ring steel stiffeners can reduce the stress concentration around the edge of holes and improve the behavior of these beams by increasing the ultimate strength and minimizing the deflection. From the numerical (FEM) results obtained by using ANSYS14, it is concluded that ultimate strength of castellated beam can be improved by providing spacer plate and ring stiffeners around the web hole. Also, the results showed that ultimate strength of octagonal castellated steel beam can be increased up to (53%) more than the parent beam (IPN140) with providing only (13.0%) weight of steel (spacer plate plus ring steel stiffeners).

This article discusses the experimental testing of tapered castellated beams (TCBs) under mid-span concentrated load. These beams are created by cutting the webs of standard I-sections in a particular zigzag pattern and rejoining the two parts by placing variable expansion plates between web posts and welding them together. Generally, the depth of the mid-span will be increased. A standard I-section (IPE140) was selected as a parent beam to fabricate three TCB specimens and one prismatic castellated beam. The experimental results showed that the ultimate load capacity of the TCBs could be increased up to 140% of the ultimate load capacity of the parent section. Fabricating a TCB is an effective way of increasing the allowable load of a long-span member while remaining within International Building Code-defined deflection limits. The experimental results showed that the allowable load at deflection (L/360) increased up to 183% of the allowable load for the control specimen at the same deflection. Finally, the experimental results showed that web-post buckling and joint-weld rupture failure modes occurred in TCBs due to the formation of high shear forces that tried to twist the web posts.

Castellated beams are broadly output from standard rolled sections, especially in (I) or (H) beam sections, and they are considered as a type of steel members with good properties. From another side, the corrugated web in beam especially trapezoidal pattern was utilized to get an improved beam strength against the shear buckling rupture, Besides, there is an advantage of stability for buckling over a plain web beam. In this paper, an experimental study has been carried out on four beams with the same length (1.7m) under one point load at mid-span. This work deals with two castellated beams with corrugated webs with and without lateral stiffeners and it had the same step length for corrugation and castellation profile. The significant variable for castellated-corrugated web beams is a total height of beams. The ultimate load capacity of castellated-corrugated web beams compared with the plain and corrugated web beams. The results showed that the load capacity of castellated-corrugated web beams without and with lateral stiffeners less than that found in flat and corrugated web beams with (23.7% and 39.4%) and (13.2% and 31.03%). The mode of failure has noticed combined between web post-buckling and flange buckling.

Reduced beam section (RBS) behaviours with various cut-flange configurations were investigated numerically in this study. A three-dimensional finite element model material non-linearity was built and validated experimentally, and the impacts of the cut--flange profile on the moment-rotation behaviour and ductility response of moment-resisting connections were investigated in a parametric form. Five-moment connections with various forms of decreasing beam flange were thus modelled using ABAQUS software and compared in terms of cyclic behaviour. RBS with circular, rectangular, trapezoidal, triangular, and drilled holes cut-flange configurations were adopted, and the finite element analysis results showed that radius cut RBS have uniform stress contours, while a re-entrant corner in rectangular, trapezoidal, or triangular cut-flange profiles’ connections may result in stress concentration, resulting in a fracture of the flange. In addition, the numerical testing showed that the RBS connection with a circular cut-flange profile offers a lower rupture index than other connections. Thus, the RBS created using circular cut-flange profiles dissipates more energy than other connections.

The present study deals with the experimental behavior of steel beams with a corrugated section, which is approximately equivalent to a compact I-shape plate girder section. Each part of the compact section (flanges and web) was transformed to its equivalent corrugated shape, depending on the available steel plate in the local market, by two plates separated by internal steel stiffeners of a zek zak shape. Six specimens were fabricated and tested in which one of them was considered as a control beam with no corrugation while the other five ones were with various schemes of corrugation for the flanges and the web . The experimental results showed that an increment of nearly 22% in the ultimate load was obtained when the section’s height increased by 25% due to the corrugation process. Furthermore, the mid-span deflection reduced by 57% as the section’s height increased by 29%. Besides, the modes of failure changed from flexural to shear in all the tested corrugated specimens.