Finite Element Modeling of Cyclic Behavior of a Reinforced Concrete Chimney Section Sami
In this study, a numerical model was presented to simulate the experimental behavior obtained for a reinforced concrete chimney section. The purpose of the previous experimental investigation conducted for the chimney section was to evaluate the effect of large openings on the cyclic response in order to reveal the performance of such structures under seismic loads. A detailed finite element model of the chimney section was constructed and all of the reinforcements of the chimney were directly taken into account by line element representations. The volume of the concrete chimney shell was modeled with hexahedral elements. A bi-linear material model was used for the reinforcements. A crucial step in the finite element approach was to employ a constitutive material model that took the multi-axial state of stress and confinement effects in concrete into account. The Winfrith concrete material model of the commercial LS-Dyna structural code was chosen for the shell of the chimney section. Comparisons of the results of the finite element study with the experimental measurements showed a good agreement for the base moment-displacement response and crack formations around the opening regions of the chimney section.
The Cyclic Behaviour of Reinforced Concrete Chimney Sections with and without Openings
The most vulnerable feature of most existing tall reinforced concrete chimneys when subject to severe earthquake excitation is the relative weakness of the sections around the openings near the chimney base. This paper documents an experimental study undertaken to investigate the cyclic behaviour of typical chimney sections with openings orientated to be bending critical and shear critical and the results are compared with previous tests with no openings. Significantly, no such cyclic tests have been previously been completed. The experimental results presented include; failure mode, over-strength factor, ultimate curvature, available ductility, hysteretic behaviour and strain distribution and the results are compared with some predictive analytical section models and design guidelines. The research indicated that chimney sections with openings were not brittle, but were significantly less ductile than sections without openings. The paper is relevant for both assessing existing chimney stacks and for the design of new chimneys in the vicinity of openings.
Climate change, disasters and electricity generation
Abbrevia ons Foreword 1. Introduc on 8 2. The impacts of changing climate pa erns and changing disaster risks on energy 9 op ons and electricity genera on infrastructure 2.1 The rela onship between climate change and disaster risks 10 2.2 The impact of changing climate pa erns and changing disaster risks on electricity 11 genera on from fossil fuels 2.3 The impact of changing climate pa erns and changing disaster risks on electricity 14 from nuclear power 2.4 The impact of changing climate pa erns and changing disaster risks on electricity 17 genera on from renewable energy 2.4.1 Hydropower 17 2.4.2 Wind Energy 19 2.4.3 Bioenergy 22 2.4.4 Solar Energy 24 3. Climate change and changing disaster risks: implica ons for energy policy and 26 planning