Optimization of welded plate girder without stiffener as per IS 800:2007

Abstract

Steel as a structural element for construction are widely used in construction of bridges, silos, furnaces, trusses and building floor, etc. Plate girder are made up from separate structural steel plates which are welded, bolted and riveted together to form flanges and web of the beam. Plate girder are often used in steel bridges and providing economical solutions in cases of large and heavy loads or in other words varies in its length under various loading conditions. Generally, optimization aims towards the best results in a given circumstance to maximize the benefits and to minimize the inputs. They are governed to improve structural properties under consideration of specified constraints. Nowadays number of optimization technique has been used in various fields. Along with the optimization techniques, various experimental works on without stiffened plate girders has also been discussed. Number of optimization techniques exists and it is inconvenient to discuss about all those techniques. Considering that, an effort is made to concentrate on techniques that are commonly adopted for the past two decades. The usual method of selecting a girder is based upon loading. Since these sections often shows that the web resists shear forces, while the flanges resist most of the bending moment experienced by the girder. Plate girder theory shows that the I-shaped section is a very efficient form for carrying both bending and shear loads in the plane of the web. Mainly while considering designing of both girder i.e. with stiffeners and without stiffener the design procedure is same and it's observed that the selection of the girder depends upon the intensity of loads, length of the girder and economy. As per structure requirement as engineer we have to select any one of these two i.e. girder with stiffener or without stiffener. So our aim is narrowed towards the study of behavior of plate girder with stiffeners on various combinations of loading and length and accordingly the cost of the girder on stability criterion as per (IS 800:2007). Also we will try to predict length, depth of girder on the basis of amount of loading and for that purpose we will generate equations which can help designer and engineer to select a suitable girder.