International Research Journal of Engineering and Technology (IRJET) Volume: 09 Issue: 06 | Jun 2022
www.irjet.net
e-ISSN: 2395-0056 p-ISSN: 2395-0072
Seismic analysis of diagrid structures with concrete filled steel tubes under various parametric study Sreelakshmi V S1, Daniel Paul Thanaraj2 1PG
student, Dept. of Civil Engineering, KMEA Engineering College, Kerala, India Professor, Dept. of Civil Engineering, KMEA Engineering College, Kerala, India ---------------------------------------------------------------------***--------------------------------------------------------------------2Assistant
Abstract – Diagrid structures have emerged as an
seismic performance of structure and the necessary carrying capacity, stiffness, and ductility.
innovative construction technique lately and has led to the advancement of tall and high-rise structures both in the engineering and architectural field. They have made structures stiffer and lighter when compared to conventional structures. Due to the inclined columns, a diagrid structural system for tall buildings produces axial force along the column direction under horizontal load which has the advantage of resisting horizontal wind and seismic load and gives more freedom to architectural design. The main aim of this paper is to study the optimum structural performance of CFST joints under various parameters by differing their diagrid angles and varying concrete property by infilling lightweight concrete (ULCC). This is to be done using the software ANSYS Workbench.
2. OBJECTIVES
To study the seismic performance of CFST columns under 2 different parameters.
3. METHODOLOGY In this paper the main aim was to study the seismic behavior of CFST as diagrid columns. The software used for modeling and analysis was ANSYS workbench. The seismic behavior was studied under two parameters. One by varying the diagrid angles and the other by varying the composition by infilling ULCC (ultra-lightweight cement composite).
The diagrid structural system has inclined columns and ring beams unlike vertical columns and horizontal beams of orthogonal or conventional structures. On applying horizontal load, the inclined columns of a diagrid structure mainly bear horizontal lateral force and produces axial force along the column direction thus eliminating second order bending moments and ensuring full use of the bearing capacity of the component. The beams and columns of conventional structures bear horizontal lateral force and produce significant bending moment and axial force, which can produce second order bending moments. The triangle formed by the intersection of ring beams and inclined columns are more stable than the quadrilateral formed by horizontal beams and vertical columns. A diagrid structure has more freedom of shape design, better internal space utilization and more material savings. So far there are no design specifications issued for diagrid structures. There are only design specifications for tall and super tall buildings which are nearly identical world-wide. In accordance with these specifications the conceptual design of tall buildings, should be paid special attention, which includes selecting uniform plane forms and structural forms, strengthening the construction measures, and selecting economic and reasonable structure systems for good resistance to earthquake and wind. Seismic design shall ensure the overall
Impact Factor value: 7.529
2. Varying concrete property by infilling lightweight concrete.
1. INTRODUCTION
|
To develop a full-scale model of a diagrid column using ANSYS Workbench.
1. Varying the diagrid angles.
Key Words: Diagrid Structures, CFST, ULCC Lightweight concrete, Diagrid angle, ANSYS Workbench.
© 2022, IRJET
4. MODELLING This section deals with the various models used in the study. For fulfilling the first part of the objective, diagrid column specimens of varying diagrid angles were analyzed. For fulfilling the next objective, the specimens infilled with light weight concrete and varying diagrid angles were analyzed. The diagrid angles adopted in the analysis process are 20⁰, 25⁰, 30⁰ and 35⁰. The specimens used have same thickness of 5.5 mm as CFST-DIC-4 but have varying diagrid angles. They are subjected to cyclic loading with an alternate push and pull on each limb which imitates the excitations of seismic waves. ANSYS Workbench is the software used for modelling the joints. The journal “Developments and mechanical behaviors of steel fiber reinforced ultra-lightweight cement composite with different densities” was referred for the study of behavior of light weight concrete infilled CFST columns. The ultra-lightweight concrete of grade U1250 was selected. It has a density of 1257.6 kg/m3 and compressive strength of 48.03 MPa. The CFST and CFST-LC (lightweight concrete infilled) columns of varying diagrid angles (20⁰,25⁰,30⁰ and 35⁰) were subjected to cyclic loading using ANSYS software
|
ISO 9001:2008 Certified Journal
|
Page 3278