IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________ Volume: 04 Issue: 12 | Dec-2015, Available @ http://www.ijret.org 156 ANALYSIS OF DIAGRID STRUCTURE IN COMPARISON WITH EXTERIOR BRACED FRAME STRUCTURE Ravish Khan 1 , S.B. Shinde 2 1 PG student, Department of Civil Engineering, Jawaharlal Nehru Engineering College, Aurangabad, Maharashtra, India 2 Head of the Department, Department of Civil Engineering, Jawaharlal Nehru Engineering College, Aurangabad, Maharashtra, India Abstract Over the last 10 years, diagrid structures have proven to be highly adaptable in structuring a wide range of building types, spans and forms. In most applications, diagrids provide structural support to buildings that are non rectilinear, adapting well to highly angular buildings and curved forms. The origin of the diagrid structural technology lies at the crossroads of engineering and architecture. The term “diagrid” have come from perimeter diagonals which have good structural efficiency and is gaining ne w interests in designing of tall structures because of its lattice like look. The term “diagrid” is a blending of the words “diagonal” and “grid” and refers to a structural system that gains its structural integrity through use of triangulation. In the diagrid structures, the vertical columns from the periphery are eliminated and this constructs the main difference between diagrids and exterior braced frames. Having triangulated configuration, the diagrids are able to carry the gravity and lateral loads. They also effectively minimize shear deformation as the diagonals carry the loads axially. The diagrid structural system is adopted these days for tall buildings because of its stiffness and flexibility in the architectural planning. This paper presents the study of 20- storey diagrid structure in comparison with exterior braced frame structure.Analysis results and design of both the models are presented in terms of storey shear, displacement, drift and summary of lateral and gravity forces. KeyWords:Diagrid structure, Exterior braced frame structure, Storey displacement, and Storey drift --------------------------------------------------------------------***---------------------------------------------------------------------- 1. INTRODUCTION Diagrids have emerged as an architectural choice in the creation of contemporary buildings.The diagrid structure consists of modules which are diamond in shape and lateral stiffness is provided more in diagrids than the other conventional type of structures.In the modern world, diagrids are gaining more popularity because of its structural flexibility and elegance in appearance. Structural engineers and architects have now made considerable progress in the trends following diagrid structures. The vertical columns in the periphery of a structure are eliminated in diagrid structures. This is the main extinguishing difference between diagrids and other forms of buildings. A triangulated configuration is formed in the diagrid structural systems because of the modules and these modules effectively carry all the loads i.e. lateral as well as gravity and distribute them in a very uniform and regular pattern. For instance, structural performance of braced tubes and diagrid structures are very familiar in a manner that both systems are able to carry lateral loads very efficiently with theirstructural member’s axial actions.While bending rigidity in braced tubes is provided primarily by vertical perimeter columns, bending rigidity in diagrids is provided by diagonals which also provide shear rigidity because the system is typically composed of only diagonals. Indeed, the diagrid systems can be called the evolution of braced tube structureswith large-diagonal members that spread over the periphery. In addition, by using diagonals, less amount of material is used. Also, due to elimination of columns, much space is available to make the structure more flexible. (a) (b) Fig -1: (a) Diagrid building, (b) Braced building Diagrids provide increased stability due to triangulation. The combination of gravity and lateral load bearing systems potentially provides more efficiency. Also, the reduced weight of the superstructure can translate into a reduced load on the foundations. A diagrid’s module has a diamond shape which contains a number of stories. Modules are classified into 4 different groups including small modules (2-4 stories), mid-size modules (6-8 stories), large modules (more than 10 stories) and irregular modules. Moreover, diagrid’sangle is the angle of diagonal members. Modules and angles both play a key role in structural, architectural and aesthetic concepts of these structures.