RESEARCH AND DEVELOPMENT CELL
This is to certify that the thesis entitled INTERACTIVE BEHAVIOR OF RESTRAINED ELEMENTS IN METAL BUILDING SYSTEMS that is being submitted by Sri P.RAVINDRA MURTHY in partial fulfillment for the award of Ph.D in CIVIL ENGINEERING WITH A SPECIALIZATION IN STRUCTURAL ENGINEERING to the Jawaharlal Nehru Technological University is a record of bonafide work carried out by him under our guidance and supervision.
The results embodied in this thesis have not been submitted to any other University or Institute for the award of any degree or diploma.
I would like to thank my supervisors, Dr.V.V.V.S.Murty and Dr.N.V.Ramana Rao, for their guidance and support especially on this dissertation. Dr.V.V.V.S.Murty and Dr.N.V.Ramana Rao has given me a passion for Structural Engineering and the motivation to excel in all endeavors. I am honored to have conducted this research under their guidance.
I would like to thank my senior colleagues of Tata Blue Scope Steel Limited, Mr. H.G. Chandra Sekhar, Mr. G.Jayaramalingam, Mr. G. Rajiv Upadhyay, Mr. Piyush Upadhyay and Mr. S.Mahesh and other colleagues of the organization for all their help and support. Also, it has been a great pleasure to be associated with them.
I would like to thank all of my colleagues in the office, both past and present, for all their support and help.
I would especially like to thank my wife, P. Nagamani and my children P.Bhavana Murthy, P.Kirtan Murthy and P. Abhinav Murthy for being my best friends and for their unending support.
I would like to extend thanks to my father, P. Sundara Murthy and my mother, P. Uma , my brother P. Vijendra Murthy and his family, my sister N. Manjulatha and her family, my sister V. Naga Maheshwari and her family.
I would like to extend thanks to my father in law, A.Vishnu Murthy and Mother In law, A. Varalaxmi and their family for their support.
I am indebted to my family for their unending support. I would like to thank my father, P.Sundara Murthy for coming to this city in hopes of a better life for himself and his family. I am thankful to my family for giving me the support and the confidence throughout my studies.
I would like to extend thanks to my friends Mr.P.Chandra Sekhar, Mr.V. Balraj, Mr. Satish Kumar , Mr. RaghuRam, and Mr.Madhusudhan Rao and other friends for their support and encouragement.
This work is dedicated to my parents and my family, with out their support none of this would have been possible. They taught me more in life than they could imagine.
I hereby declare that the thesis entitled INTERACTIVE BEHAVIOR OF RESTRAINED ELEMENTS IN METAL BUILDING SYSTEMS is entirely original and has not formed previously the basis for the award of any degree,diploma associating or other similar titles.
Majority of the structural members of a metal building system are subjected to considerable restraints under the working conditions, either inherent in the construction of the system or deliberately applied as a precaution against buckling. These restraints have the effect of increasing the stability of the structural members.
It is well known that an elastic lateral brace (by means of secondary elements like purlins/girts and flange Braces. etc) restricts partially the lateral buckling of web tapered I-members in a metal building frame and increases the elastic buckling strength. However, studies of the effects of elastic restraints on the flexural torsional buckling of web tapered I-beams do not appear to have reported, and it seems extending research findings relevant to buckling of the restrained beams and columns to web tapered I-members needs further investigations.
There may be situations in practice, however where the effect of continuity is drastically diminished, especially when the lateral supports have inadequate stiffness and /or are improperly applied to the web tapered members. In these cases the usual design practice is to ignore the effect of continuity due to lateral restraints. This research proposes to determine the optimum stiffness of the lateral restraints for the web tapered beams, utilization of the available lateral stiffness and considering the improvement in the strength of the web tapered I-members than ignoring the effect of the lateral stiffness which is available in the metal building systems.
This Research develops a three dimensional Finite Element modeling and analysis using the Finite Element Program and uses to investigate the effect of the elastic lateral bracing stiffness on the inelastic flexural torsional buckling of simply supported web tapered I-beams with an elastic lateral restraint under pure moment.