Critical local damage scenarios for robustness assessment of irregular structures
File(s)
Author(s)
Grosman, Stanyslav
Type
Thesis
Abstract
Modern-day architects tend to use singular and non-repeatable shapes for building
structures. Currently, scenarios for robustness assessment of such structures are defined based
on engineering judgement, which can result in designs that are insufficiently robust. This thesis
focuses on development of a rigorous robustness assessment framework capable of reliably
determining critical scenarios for irregular building structures.
To reduce the computational demand associated with analysis of detailed numerical
models of building structures undergoing robustness assessment, a novel shell element capable
of effectively modelling reinforced concrete slabs under extreme loading conditions is
developed. A comparative study conducted in this work demonstrates the computational
efficiency of the new element without compromising the accuracy of the modelled response.
To address the needs of robustness assessment in the early design stage, a gradient based
methodology, founded on the general concepts of topology optimisation, is developed. This
methodology is capable of determining critical zones of the considered structure efficiently and
to obtain a good estimate of its robustness. The developed methodology is based on an
enhancement of the robustness assessment framework developed at Imperial College London,
enabling a rational evaluation of robustness for sudden local damage scenarios. To facilitate the
convergence of the developed procedure, a simple yet reasonably accurate approach for
estimating the sensitivity of the robustness measure to the changes in damage parameters is
developed and verified.
To provide a reliable framework for estimating robustness at the final stage of design, an
efficient global approach based on a meta-modelling technique is developed within the
robustness assessment framework. This approach benefits from the developed variant of multifidelity kriging algorithm. The proposed modification utilises a set of independent low fidelity
models, obtained through the subdivision of the high-fidelity model into a set of a priori
established components. Employing the developed approach these models can be assembled to
construct a composite low fidelity model for the response of the whole structure.
The developed framework is finally applied in a detailed case study to the robustness
assessment of the Agora Garden Tower. This study successfully identified all of the critical
scenarios as well as their respective robustness measures. The results of the robustness
assessment indicated that concepts commonly accepted for the regular structures do not
necessarily hold for specific types of irregular ones, which provides strong support to the
original motivation for the conducted research.
structures. Currently, scenarios for robustness assessment of such structures are defined based
on engineering judgement, which can result in designs that are insufficiently robust. This thesis
focuses on development of a rigorous robustness assessment framework capable of reliably
determining critical scenarios for irregular building structures.
To reduce the computational demand associated with analysis of detailed numerical
models of building structures undergoing robustness assessment, a novel shell element capable
of effectively modelling reinforced concrete slabs under extreme loading conditions is
developed. A comparative study conducted in this work demonstrates the computational
efficiency of the new element without compromising the accuracy of the modelled response.
To address the needs of robustness assessment in the early design stage, a gradient based
methodology, founded on the general concepts of topology optimisation, is developed. This
methodology is capable of determining critical zones of the considered structure efficiently and
to obtain a good estimate of its robustness. The developed methodology is based on an
enhancement of the robustness assessment framework developed at Imperial College London,
enabling a rational evaluation of robustness for sudden local damage scenarios. To facilitate the
convergence of the developed procedure, a simple yet reasonably accurate approach for
estimating the sensitivity of the robustness measure to the changes in damage parameters is
developed and verified.
To provide a reliable framework for estimating robustness at the final stage of design, an
efficient global approach based on a meta-modelling technique is developed within the
robustness assessment framework. This approach benefits from the developed variant of multifidelity kriging algorithm. The proposed modification utilises a set of independent low fidelity
models, obtained through the subdivision of the high-fidelity model into a set of a priori
established components. Employing the developed approach these models can be assembled to
construct a composite low fidelity model for the response of the whole structure.
The developed framework is finally applied in a detailed case study to the robustness
assessment of the Agora Garden Tower. This study successfully identified all of the critical
scenarios as well as their respective robustness measures. The results of the robustness
assessment indicated that concepts commonly accepted for the regular structures do not
necessarily hold for specific types of irregular ones, which provides strong support to the
original motivation for the conducted research.
Version
Open Access
Date Issued
2019-09
Date Awarded
2019-12
Copyright Statement
Creative Commons Attribution NonCommercial Licence
Advisor
Izzuddin, Bassam
Publisher Department
Civil and Environmental Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)