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Dynamická analýza konstrukce zatížená seismickým zatížením / Dynamic analysis of structure loaded seismic loadsŠulerová, Zdeňka January 2014 (has links)
This thesis deals with the calculation of response of reinforced concrete construction on the effect of seismic tension. Time and spectral analysis were made. They are mentioned as possible ways of calculation in EN 1998 - 1:2004 norm. Final figures of global deformations and stress on selected beam from the time and spectral analysis were firstly compared for the horizontal components of seismic stress affecting only in one direction. Subsequently comparison of time progress to combination of these effects mentioned in relevant norm was made. In the conclusion the results of used analysis are appraised.
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The Effect of Masonry Infill On The Seismic Behaviour of Reinforced Concrete Moment Resisting FramesBasiouny, Wael January 2009 (has links)
<p> A moment resisting frame is one of the most commonly used lateral load resisting system in modem structures because it is suitable for low and medium rise buildings and industrial structures. It can be designed to behave in a ductile manner under seismic loads. </p>
<p> Masonry infills have traditionally been used in buildings as partitions and for architectural or aesthetic reasons. They are normally considered as non-structural elements, and their effect on the structural system has been ignored in the design. However, even though they are considered non-structural elements, there is mounting evidence that they interact with the frame when the structures are subjected to lateral loads
Infill walls have been identified as a contributing factor to catastrophic structural failures during earthquakes. Frame-infill interaction can induce brittle shear failures of reinforced concrete columns by creating a short column. Furthermore, infills can over-strengthen the upper stories of a structure and when they fail a soft first storey is created, which is highly undesirable from the earthquake resistance standpoint. </p>
<p> There is a need for an efficient and accurate computational model to simulate the nonlinear hysteretic force-deformation behaviour of masonry infills, which is also suitable for implementation in time-history analysis of large structures. The aim is to develop a simplified advanced and cost-effective model for nonlinear time history analysis and seismic design of masonry infill frame structures. </p>
<p> The objective of this research was to develop a practical and economical technique applicable for global analysis of general three-dimensional reinforced concrete infilled frames under lateral loads. Novel finite element model for the infill and the surrounding frame was developed using a special finite element configuration to represent the masonry panel. Some prescribed failure planes in different directions were defined depending on the common failure mode of masonry panels. Moreover, some of contact elements were used on the failure planes to connect among the panel elements, and between the panel elements and the boundary reinforced concrete frame. Different material models were used to represent the behaviour of concrete, reinforcing steel, mortar joints and inclined saw-tooth cracks in the infill panel. Different material models were used to describe the behaviour through and perpendicular to the prescribed failure planes. The proposed model and the used material models were described in details in the first part of this research. </p>
<p> The proposed finite element model was verified against experimental and analytical results previously published by others. Different frames configurations, reinforcing details, boundary conditions and material properties were consider in that section to verify the capability of the proposed model to simulate the behaviour of different frames. The overall behaviour "Load-deflection relationship", failure point and failure mode were compared with the experimental and analytical results. Satisfactory agreement with the previously published results was obtained. </p>
<p> The study investigates the capability of the proposed model to simulate the behaviour of infilled frames subjected to cyclic loads. Hysteretic loops obtained by using the new model were verified against experimental and analytical results and good correlation were obtained. The failure modes and crack patterns were compared with the experimental results and good agreements were obtained. The proposed model failed to capture some shear cracks in the RC frames as per the experimental results. </p> / Thesis / Doctor of Philosophy (PhD)
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WALL-DIAPHRAGM OUT-OF-PLANE COUPLING INFLUENCE ON THE SEISMIC RESPONSE OF REINFORCED MASONRY BUILDINGSAshour, Ahmed January 2016 (has links)
Recent research interests in studying the performance of different seismic force resisting systems (SFRS) have been shifting from component- (individual walls) to system-level (complete building) studies. Although there is wealth of knowledge on component-level performance of reinforced masonry shear walls (RMSW) under seismic loading, a gap still exists in understanding the response of these components within a complete system. Consequently, this study’s main objective is to investigate the influence of the diaphragm’s out-of-plane stiffness on the seismic response of RMSW buildings. In addition, the study aims to synthesize how this influence can be implemented in different seismic design approaches and assessment frameworks. To meet these objectives a two-story scaled asymmetrical RMSW building was tested under quasi-static cyclic loading. The analysis of the test results showed that the floor diaphragms’ out-of-plane stiffness played an important role in flexurally coupling the RMSW aligned along the loading direction with those walls orthogonal to it. This system-level aspect affected not only the different wall strength and displacement demands but also the failure mechanism sequence and the building twist response. The results of the study also showed that neglecting diaphragm flexural coupling influence on the RMSW at the system-level may result in unconservative designs and possibly undesirable failure modes. To address these findings, an analytical model was developed that can account for the aforementioned influences, in which, simplified load-displacement relationships were developed to predict RMSW component- and system-level responses under lateral seismic loads. This model is expected to give better predictions of the system response which can be implemented, within the model limitations, in forced- and displacement-based seismic design approaches. In addition, and in order to adapt to the increasing interest in more resilient buildings, this study presents an approach to calculate the system robustness based on the experimental data. Finally, literature shows that the vast majority of the loss models available for RMSW systems were based on individual component testing and/or engineering judgment. Consequently, this study proposes system damage states in lieu of component damage states in order to enhance the prediction capabilities of such models. The current dissertation highlights the significant influence of the diaphragm out-of-plane stiffness on the system-level response that may alter the RMSW response to seismic events; an issue that need to be addressed in design codes and standards. / Dissertation / Doctor of Philosophy (PhD)
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Сравнительный анализ сборно-монолитных систем Китая и России: разработка предложений по усовершенствованию узлов сопряжения стен для работы на сейсмические нагрузки : магистерская диссертация / Comparative analysis of prefabricated monolithic systems in China and Russia: development of proposals for improving wall interface units for operation under seismic loadsВан, Х., Wang, H. January 2023 (has links)
Сборно-монолитные здания – распространенный вид строительства на сегодняшний день. Сборно-монолитные здания появились в России в 1970-х годах и в Китае в 1990-х годах. В данной работе сравнивается распространенная китайская модель строительства, имеющей стеновую конструктивную схему, с наиболее похожей российской системой. Анализ конструктивного исполнения узлов сопряжения несущих стен между собой показал их низкую несущую способность при действии сейсмических нагрузок. В работе выполнено математическое обоснование и разработано предложение по усовершенствованию данных узлов сопряжения путем введения в их работу шарниров, что значительно увеличивает несущую способность стыкового соединения при действии сейсмических нагрузок. / Prefabricated monolithic buildings are a common type of construction today. Prefabricated monolithic buildings appeared in Russia in the 1970s and in China in the 1990s. This paper compares the common Chinese construction model, which has a wall structure, with the most similar Russian system. An analysis of the design of the joints between the load-bearing walls showed their low load-bearing capacity under the action of seismic loads. The work carried out a mathematical substantiation and developed a proposal to improve these interface units by introducing hinges into their operation, which significantly increases the load-bearing capacity of the butt joint under the action of seismic loads.
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