Performance of Confined Columns using FEM Modeling

Abstract

Performance of Confined Columns Using FEM Modelling.

A Thesis of Master of Science

By ATIQ AHMAD JAN (NUST-2016-MS-SE-0000170421)

DEPARTMENT OF STRUCTURAL ENGINEERING “MILITARY COLLEGE OF ENGINEERING, RISALPUR NATIONAL UNIVERSITY OF SCIENCE AND TECHNOLOGY ISLAMABAD” (2020)

THESIS ACCEPTANCE CERTIFICATE

This is to certify that the Thesis titled

Performance of Confined Columns Using FEM Modelling

Submitted by

ATIQ AHMAD JAN

Has been accepted towards the partial fulfillment Of the requirements for the degree Of Master of Science in Structural Engineering

SUPERVISOR: ______________________________ ASSOCIATE PROFESSOR (Dr. MUHAMMAD RIZWAN) MILITARY COLLEGE OF ENGINEERING, RISALPUR NATIONAL UNIVERSITY OF SCIENCES AND TECHNOLOGY, ISLAMABAD

CERTIFICATE OF ORIGINALITY I hereby declare that the research paper titled “PERFORMANCE OF CONFINED COLUMNS USING FEM MODELLING” my own work and to the best of my knowledge. It contains no materials previously published or written by another person, nor material which to a substantial extent has been accepted for the award of any degree or diploma at NUST or any other education institute, except where due acknowledgment, is made in the thesis. Any contribution made to the research by others, with whom I have worked at MCE/NUST or elsewhere, is explicitly acknowledged in the thesis.

I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project’s design and conception or in style, presentation and linguistic is acknowledged. I also verified the originality of contents through plagiarism software.

Author Name: Atiq Ahmad Jan Signature: ¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬______________ (NUST-2016-MS-SE-0000170421) MS Structural Engineering, Military College Of Engineering, Risalpur.

PLAGIARISM CERTIFICATE

It is certified that MS Thesis Titled Performance of confined columns using FEM modelling by Atiq Ahmad Jan has been examined by us. We undertake the follows: a. Thesis has significant new work/knowledge as compared already published or are under consideration to be published elsewhere. No sentence, equation, diagram, table, paragraph or section has been copied verbatim from previous work unless it is placed under quotation marks and duly referenced. b. The work presented is original and own work of the author (i.e. there is no plagiarism). No ideas, processes, results or words of others have been presented as Author own work. c. There is no fabrication of data or results which have been compiled/ analyzed. d. There is no falsification by manipulating research materials, equipment or processes, or changing or omitting data or results such that the research is not accurately represented in the research record. e. The thesis has been checked using TURNITIN (copy of originality report attached) and found within limits as per HEC plagiarism Policy and instructions issued from time to time.

Name & Signature of Student Atiq Ahmad Jan Signature: ________________ Name & Signature of Supervisor with Stamp Maj Dr Muhammad Rizwan Signature: ________________

DEDICATION

To My Worthy Parents and Teachers.

ACKNOWLEDGEMENTS

To Allah almighty, the most merciful and most gracious, who gave me the courage and strength to come this far, and made me able to achieve yet another milestone of my life. To my parents who have always provided me with their constant love and unending support to go through many of my endeavors, stood by me whenever I were in dark, and lend me with a helping hand whenever I were down. I acknowledge my worthy faculty who lighted my path with their efforts, turned the obstacles of my way into stepping stones, and kept teaching me even when I asked the most stupid questions. I am forever in debt to you all. I would like to extend my humblest of gratitude to my worthy Supervisor, Dr. Muhammad Rizwan. Your efforts for my success are something that would always be an inspiration for me in my life ahead. Thank you for being my mentor, for being my inspiration, and for being my Supervisor. I extend my regards to everyone who helped me throughout this research and make it a success.

ABSTRACT Results of testing of prototype specimens of various structural member is important to understand their seismic behavior however such experiments require high tech labs, financial support and efforts. In such situation carefully calibrated models can be very useful. These models are available to professional and researchers to compare/study effect of their selected parameters. These models are also important in studying and understanding behavior of various structural members subjected to specialized loading. In this research the experimentally tested reinforced concrete columns were modeled in three-dimensional simulation modules, ANSYS and DRAIN-3DX.”Seven columns of same geometrical dimensions with different material properties and specifically different configuration, these configurations involved standard stirrups and newly proposed steel strips, and types of confinement reinforcement were selected for modeling and simulation. the three-dimensional model of the first column was simulated using different approaches involving different Elements, Element shapes, material models, sub GUI’s of FEM. The modeling was carried through calibration of backbone curve of analytically generated hysteresis response with the back-bone curves of experimentally achieved hysteresis response. The standard stirrups were calibrated first and effect of confinement of newly proposed steel strips was captured through adjustment of various key parameters. After the calibration and validation of material models an analytical model of standard stirrup column, stress strain model of unconfined concrete was developed. using the calibrated data of ANSYS calibrated models for the inputs of ANSYS concrete modeling. Lastly the confinement model proposed by the previous researchers was used instead of confining reinforcement, comparison is presented with actual response and the best modeled is finalized for future modeling of square column under axial load and static cyclic loading. The presented work will be useful for structural engineers involved in research and industry.