Academic literature on the topic 'Buildings, structurs'

Metal building frames are typically designed using welded prismatic and web-tapered members with doubly-symmetric and/or singly-symmetric cross sections. Until recently, the base U.S. provisions for design of frames with web-tapered members were provided in the AISC ASD (1989) and LRFD (1999) Specifications. Unfortunately, these previous AISC provisions address only a small range of practical designs. As a result, metal building manufacturers have tended to develop their own methods for design of the wide range of nonprismatic member geometries and configurations encountered in practice. This research develops new design procedures for design of frames using general prismatic members and web-tapered members. An equivalent prismatic member concept utilized in prior research and the prior AISC provisions is generalized to accommodate the broad range of member types and configurations commonly used in metal building industry. Furthermore, the new design procedures incorporate many of the improvements achieved in the AISC (2005&2010) Specifications to metal building frame design. These improvements include a new stability design method, the direct analysis method, more complete considerations of different column buckling limit states (flexural, torsional and flexural-torsional buckling), and improved axial load and flexural resistance provisions. This research develops practical design-based procedures for simplified calculation of the elastic buckling resistances of prismatic and web-tapered members to facilitate the application of the proposed design methods. In addition, this research performs a relatively comprehensive assessment of beam lateral torsional buckling (LTB) behavior and strength of prismatic and web-tapered members using refined virtual test simulation. It is demonstrated that web-tapered members behave in a comparable fashion to prismatic members. Based on the virtual simulation study, recommendations for potential improvement of the AISC LTB resistance equations are provided. Lastly, the strength behavior of several representative metal building frames is studied in detail using the same virtual test simulation capabilities developed and applied for the assessment of the beam LTB resistances.

This research is a fundamental step towards intelligent building structures with load sensing characteristics. It is argued, with evidence from industry leaders, that these will become ubiquitous. It draws inspiration from developments in structural health monitoring of infrastructure projects. It addresses the current gap between the intellectual effort spent by design teams to conceive building structures that satisfy client brief and informational lacunae on the performance of the building structures. This gap restricts opportunities to adapt buildings in future investment cycles. The research poses a challenge: ‘can a novel system be implemented in a building structure to allow real-time monitoring of the performance of key structural elements?’ effectively moving towards intelligent, adaptable buildings. Infrastructure projects which had structural health monitoring systems implemented to monitor and mitigate damage are reviewed. These served as analogues on how to harness data acquired by sensors, transfer them to the building management system and inform decision making. The hypothesis that there is a need to incorporate smart sensors in building structures was put to the test in interviews with thirty business leaders in the construction industry. These interviews identified key attributes that needed to be satisfied by the sensors. Novel stress sensors based on nanocomposite polymer films were explored and tested in laboratory-based experiments both under short-term and long-term loading. The sensitivity of the sensors to a change in load was assessed. Scanning electron microscopy and Raman spectroscopy were carried out to assess the characteristics of the sensors. A novel stress sensor, based on a carbon nanotube/polycarboxylate polymer film sandwiched between cement grout layers, was found to be the most sensitive to change in electrical resistance measured when the imposed load was changed. A gauge factor two orders of magnitude greater than the highest factor reported to date on research on stress sensors was determined. This research prepares the ground and maps out the strategic and tactical challenges that are needed to arrive at operational, long timescale, load sensing for buildings.

Architecture in life is the light of the culture in any society and closely relates with historical, political, economic and social aspects of the society. Persian architecture and building construction should be properly examined from the depths of the history of this ancient land. Persian architecture goes back to six centuries before Christ and it has over 6000 years of continuous history. Since then ever, architecture has been related to various issues, especially religious, and has developed and evolved for centuries. Persian architecture has features that in comparison with other countries are of particular value. Properties such as good design, precise calculations, the correct form of coverage, compliance with technical and scientific issues in the building, high balconies, tall pillars and the various decorations that each of them represent the magnificent of Persian architecture. This study assumes that architecture and building construction are the full manifestation of human culture, and focus on some of the important elements in traditional Persian architecture: windwards, traditional refrigerators and foundations.

Following the evolution of a damage avoidance design (DAD) frame system, with rocking beam-column joints, at the University of Canterbury, analytical studies are carried out to evaluate the performance of proposed structures, and verify the proposed design methodology. A probabilistic seismic risk assessment methodology is proposed, from which the expected annualised financial loss (EAL) of a structure can be calculated. EAL provides a consistent basis for comparison of DAD frame systems with state-of-practice ductile monolithic construction. Such comparison illustrates the superior performance of DAD frame systems. The proposed probabilistic seismic assessment methodology requires the response of the structure to be evaluated over a range of seismic intensities. This can be achieved by carrying out an incremental dynamic analysis, explicitly considering seismic randomness and uncertainty; or from a pushover analysis, and assuming an appropriate value of the dispersion. By combining this information with the seismic hazard, probabilistic response curves can be derived, which when combined with information about damage states for the particular structure, can be transformed into 'resilience curves'. Integration of information regarding the financial loss occurring due to each of the damage states, results in an estimate of EAL.

The amount of total and relative sway of a framed or a composite (frame-shear wall) building is of utmost importance in assessing the seismic resistance of the building. Therefore, the design engineer must calculate the sway profile of the building several times during the design process. However, it is not a simple task to calculate the sway of a three-dimensional structure. Of course, computer programs can do the job, but developing the three-dimensional model becomes necessary, which is obviously tedious and time consuming. An easy to apply analytical method is developed, which enables the determination of sway profiles of framed and composite buildings subject to seismic loading. Various framed and composite three-dimensional buildings subject to lateral seismic loads are solved by SAP2000 and the proposed analytical method. The sway profiles are compared and found to be in very good agreement. In most cases, the amount of error involved is less than 5 %. The analytical method is applied to determine sway magnitudes at any desired elevation of the building, the relative sway between two consecutive floors, the slope at any desired point along the height and the curvature distribution of the building from foundation to roof level. After sway and sway-related properties are known, the requirements of the Turkish Earthquake Code can be evaluated and / or checked. By using the analytical method, the amount of shear walls necessary to satisfy Turkish Earthquake Code requirements are determined. Thus, a vital design question has been answered, which up till present time, could only be met by rough empirical guidelines. A mathematical derivation is presented to satisfy the strength requirement of a three-dimensional composite building subject to seismic loading. Thus, the occurrence of shear failure before moment failure in the building is securely avoided. A design procedure is developed to satisfy the stiffness requirement of composite buildings subject to lateral seismic loading. Some useful tools, such as executable user-friendly programs written by using &ldquo<br>Borland Delphi&rdquo<br>, have been developed to make the analysis and design easy for the engineer. A method is also developed to satisfy the ductility requirement of composite buildings subject to lateral seismic loading based on a plastic analysis. The commonly accepted sway ductility of &amp<br>#956<br>&amp<br>#916<br>=5 has been used and successful seismic energy dissipation is thus obtained.

This thesis presents the formulation of a novel methodology to design adaptive structures. This method is based on improving structural performances through the reduction of the embodied energy in the material at the cost of a small increase in operational energy necessary for structural adaptation and sensing. In structural design, members are sized so that they have the capacity to meet the worst expected ‘effect’ or ‘demand’ from all load cases. If embodied energy is to be saved, clearly, member sizing should not be governed directly by the worst demand but by some fraction of it. The design method proposed here seeks to synthesise structural configurations which can be thought of as a hybrid between a passive and a fully active structure. Instead of using more material to cope with the effect of loads, here strategically located active elements (actuators) provide controlled output energy to manipulate actively the internal flow of forces into more efficient load paths (i.e. stress homogenisation) and keep displacements within desired limits by changing the shape of the structure. To ensure the embodied energy saved this way is not used up to by actuation, the adaptive solution is designed to cope with ordinary loading events using only passive load bearing capacity whilst relying on active control to deal with events that have a smaller probability of occurrence (e.g. wind storms, snow, earthquakes, unusual crowds but also moving loads such as trains). A nested optimisation scheme finds the active-passive system that corresponds to the minimum of the sum of embodied and operational energy. This work on adaptive structures comprises both a numerical and an experimental component. Numerical simulations and experimental tests carried out on a purpose-built large scale prototype confirmed that substantial savings up to 60% of the total energy can be achieved by adaptive solutions.

The lateral stiffening effects of cladding and partition walls, which are usually unaccounted for in a building structure's design, are investigated in this research project. Direct and iterative, linear elastic finite element analyses of representative modules of these components and their supporting primary structure were performed. These were used to study their general lateral load behaviour, and to establish their modes of interaction and induced forces. As a result, new and practical analogous strut models have been devised to allow their incorporation in, and the analysis of, the total building structure. The strut models permitted the effects of the non-structural elements' interaction on the static and dynamic responses of tall building structures to be studied. The ultimate objective of this work has been to contribute towards the development of new procedures of analysis and design of building structures braced by precast concrete cladding panels and non-loadbearing concrete blockwork walls.