1,721,041 research outputs found
Fixed supports and realistic blast studies
No full textReal design scenarios are likely to differ in several respects from the analysed situations. One of these is the boundary condition. In the cases considered previously, the slabs were always simulated as simply supported, since this was the condition generally used during the tests. In realistic structures it is more likely that the concrete elements will have fixed boundary conditions, as these better represent the reinforcement ties generally included in design. Additionally, lower stand-offs and more concentrated fragment distributions are also likely to be required when design conditions are determined. Therefore, it was decided that the ability of modelling such different situations was an important parameter to assess the capability of the modelling method developed
Impact tests and pre blast tests predictions
No full textIn this context, it was decided to consider the performance of steel vertical structures, composed of several steel universal beam (UB) sections welded together, with additional protective steel plates on each face. Additionally, a steel-concrete sandwich panel type was also included. It was decided that they would be included in the study to assess their performance with realistic charges.
To fully consider the behaviour of these structures and to inform modelling techniques to be used to facilitate their design, it was decided to conduct a series of experiments, including both impact and blast tests. These would then be used to validate detailed numerical models, with a special attention to developing blast tests prediction capabilities
Literature review on existing analysis and design methodology for FRP-strengthened RC walls subject to near-field blast effect
No full textThis report has presented a review of experimental and finite element research on RC slab and walls with/without FRP retrofitted subjected to blast loading. It can be seen that FRP retrofitted structure component has a much better blast resistance by increasing of strength and ductility than non-retrofitted case. For non-retrofitted RC slab and wall, there are some engineering tools and design guide lines existing based on test results or finite element results, but for FRP retrofitted RC slab and wall, there is no such fast running tool. So it is a task to develop such running tool to guide the application of FRP retrofitted structure. Test work and FE work should be both carried out to finish this task
Literature review on fibre reinforced polymer (FRP) properties and test results used to establish such properties in numerical modelling
No full textTo evaluate FRP strengthening effect properly, some detail behaviours of FRP is required for high fidelity numerical simulation, for example, FRP strain rate effect, dynamic bond-slip theory between FRP and concrete. Experiments were carried out to explore FRP working process with concrete wall under close-in explosion
Parametric studies on the behaviour of FRP-strengthened RC wall subject to near-field blast effects and fragment loading and development of fast running model (FRM)
No full textBased on the high-fidelity physics based models (HFPBMs) described in report D3, mass runs have been carried out for parametric studies to investigate the influence of material properties and structural parameters on the behaviour of FRP-strengthened RC walls subject to near-field blast effects and fragment loading. Following this, the results obtained from the mass runs have been analyzed using artificial neural network (ANN) methods to develop FRM (Fast running model). Based on the FRM, analysis tools have been developed and preliminary design guidelines are being proposed
High-fidelity physics based models (HFPBM) for FRP-strengthened RC walls subject to near-field blast effects and fragment loading
No full textIn this report D3, the aim is to develop a high-fidelity physics based models (HFPBM) by commercial hydro code LS-DYNA for FRP-strengthened RC walls subject to near-field blast effects and fragment loading.
The models should be validated using the DSTA test results or other available test results.
Based on the work from report D1, D2 and also some other previous projects by our group, in this report D3, the involved techniques of numerical simulation will be investigated one by one. Finally high-fidelity physics based models (HFPBM) will be developed
Advanced scenario modelling
No full textConcrete structures used for defence applications have to be able to resist sever dynamic loading caused by bomb blasts in their vicinity. Whilst concrete components are well placed to resist blast pressure waves, they can suffer high levels of damage due to fragment impacts. It is therefore important to include this loading in their analysis to ensure the final design will provide adequate protection to people and equipment.In this advanced scenario phase of the project the modelling techniques were required to be developed to include the simulation of loading from real ordinances instead of the idealised charges used in the basic scenario
Behaviour of bolted beam-column joint with sudden column removal
No full textStructural progressive collapse possesses a great threat to humanity. Therefore, scientist and researchers from all over the world are looking into this topic with great scrutiny. Most of the past studies focused on progressive collapse of RC structures, but few have researched on the progressive collapse of steel structures. As steel structures are increasingly popular in modern day construction, and through various advancement of construction technology, it is important that more study has to be done to enhance the quality of steel structures in the future.
As there are many reasons that lead to the collapse of a multi-storey structural frame, this final year report focused on the behaviour of bolted beam-column joints during sudden column removal. The sudden column removal illustrates events such as blasting of columns or outbreak of fire that causes column to disintegrate apart. Moreover, the author also cooperated with his project partner to discuss about the effect of braced column and unbraced column on the robustness of structure. Besides that, parameter studies were also done to further understand the behaviour of bolted connections under sudden column removal. Some of the parametric studies done are plate thickness, bolt strength, boundary conditions, and time taken to remove the column.
In the final year report, the author was aided with modern software called ABAQUS 6.12 which uses finite element method. However, a great understanding of the software played a major part of completing this report. All the parameters, materials and interactions between surfaces were to be defined by the author with great detail. Both two dimensional and three dimensional models were created to aid the author in the study.Bachelor of Engineering (Civil
Behaviour of bolted beam-column joint with sudden column removal
No full textStructural progressive collapse possesses a great threat to humanity. Therefore, scientist and researchers from all over the world are looking into this topic with great scrutiny. Most of the past studies focused on progressive collapse of RC structures, but few have researched on the progressive collapse of steel structures. As steel structures are increasingly popular in modern day construction, and through various advancement of construction technology, it is important that more study has to be done to enhance the quality of steel structures in the future.
As there are many reasons that lead to the collapse of a multi-storey structural frame, this final year report focused on the behaviour of bolted beam-column joints during sudden column removal. The sudden column removal illustrates events such as blasting of columns or outbreak of fire that causes column to disintegrate apart. Moreover, the author also cooperated with his project partner to discuss about the effect of braced column and unbraced column on the robustness of structure. Besides that, parameter studies were also done to further understand the behaviour of bolted connections under sudden column removal. Some of the parametric studies done are plate thickness, bolt strength, boundary conditions, and time taken to remove the column.
In the final year report, the author was aided with modern software called ABAQUS 6.12 which uses finite element method. However, a great understanding of the software played a major part of completing this report. All the parameters, materials and interactions between surfaces were to be defined by the author with great detail. Both two dimensional and three dimensional models were created to aid the author in the study.Bachelor of Engineering (Civil
Behavior of flush end plate steel joints with sudden column removal
No full textThe use of steel in building design is increasingly become more popular. Steel design provides a more ductile and robust structure, together with a more practical way of assembly method. All of these are made possible by the advanced construction technology and research. It is foreseen that the use of structural steel will be more favored in the future. Hence, more study needs to be done to ensure a better steel structure quality for future use.
As strong and practical a steel structure is, it has a critical point that requires special attention during design: the joints. There have been a number of studies focusing on the joint behavior during column removal, but none of them focused on the joints adjacent to the one above the removed column. Supported with this fact, this final year project will then discuss about the behavior of flush end plate connections located adjacent to the joint immediately above the removed column.
This project focused on the creation of a 3 Dimensional, finite element model of the joint. ABAQUS 6.11 was used as the main modeling software. Although the author has been aided with a modern software, it is required that she defines all of the member properties in the model, including the failure criterion of the joint which was found to be the bolts based on previous studies. During the modeling process, combination of 2 and 3 Dimensional models were applied for practicality of the modeling and calculation process. Expertise in such skills will reduce the calculation time significantly.
Parametric study is done to further understand the behavior of flush end connection under a sudden column removal scenario. The parameters used in this study are: plate thickness, plate strength, boundary conditions and the number of bays in the model.Bachelor of Engineering (Civil
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