BUCKLING ANALYSIS OF THIN WALLED BOX GIRDER

Abstract

Composite box beam is the basic building block. It can be used both as a compression member and flexural member. Over the past decade composites are gaining popularity in marine, aerospace and civil industry for numerous structural applications. Being lightweight it is easy to handle and transport leading to short installation times and speedy construction which is a major. criteria during disasters. Also the quality of work is improved in terms of corrosion resistance, endurance limit, damage tolerance, aesthetic appearance, longer life, low maintenance, fire, etc. For an instance FRP decks weighs approximately 80 percent less than a concrete deck. Reducing the dead load increasing the allowable load capacity of bridge without any significant damage to the existing superstructure, thus lengthening its service life. Versatility of the material is such that it can be used even in earthquake prone areas for seismic retrofit of for remote installations in difficult terrains. Further the flexibility to tailor different properties of the structural elements by varying fiber orientation, number of layers etc. to achieve the strength and stiffness requirements in the required direction has enhanced their usage. Need of appropriate structural form of composite is required to utilize its advantages. Thin-wa11ed box beam is chosen for study as it offers excellent tiexural and torsional stifthess with minimum weight. Use of composite in box beam form combines the advantages of both the material and form and results in an efficient generic structural element. Hence use of the composite materials for these structural elements is aptly suited as they provide flexibility to designer to specify different material properties for different elements of the beam cross-section. This enables the shape of the cross-section to exploited to fullest by judicious arrangement of plies within the composites panels, which forms beams. The vast array of the design variables for composite contrasts sharply with traditional materials where choices are limited and hence complicates the design. Due to large number of human intuition will not work and use of computational procedures coupled data base should be considered in improving design. So the present study is carried out, to understand the behaviour of the composite box girder. As material use composite material, so the section tends to be thin. And thin sections govern the buckling criteria. Thus buckling analysis of the box girder becomes important. Past failures in box girder happened due to box girder at web section, so the present studies are carried out by considering buckling analysis of box girder in web through ANSYS. So under different loading and geometry of the box sections studies are carried out , which can be useful for further research and analysis on the composite box girder.