The current impetus for alternative energy sources is increasing the demand for solar energy technologies in Florida – the Sunshine State. Florida’s energy production from solar, thermal or photovoltaic sources accounts for only 0.005% of the state total energy generation. The existing types of technologies, methods of installation, and mounting locations for solar panels vary significantly, and are consequently affected by wind loads in different ways. The fact that Florida is frequently under hurricane risk and the lack of information related with design wind loads on solar panels result in a limited use of solar panels for generating energy in the “Sunshine State” Florida. By using Boundary Layer Wind Tunnel testing techniques, the present study evaluates the effects of wind on solar panels, and provides explicit and reliable information on design wind loads in the form of pressure coefficient value. The study considered two different types of solar panel arrangements, (1) isolated solar panel and (2) arrays, and two different mounting locations, (1) ground mounted and (2) roof mounted. Detailed wind load information was produced as part of this study for isolated and arrayed solar panels. Two main conclusions from this study are the following:(1) for isolated solar panel with high slopes the wind load for wind angle of attack (AoA) perpendicular to the main axis exhibited the largest wind loads; (2) for arrays, while the outer rows and column were subjected to high wind loads for AoA perpendicular to the main axis, the interior solar panels were subjected to higher loads for oblique AoA.

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Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / Wind pressures affect buildings of all shapes and sizes. Standards and codes have been published that instruct engineers and designers how to account for the wind loads interacting with structures. As further research on wind interaction with buildings is completed, more provisions and requirements are added to the codes and standards. At what point do the provision modifications and additions become more complicated than they need to be for a safe, effective building design? This report evaluates the progression of wind provisions through codes and standards since the early 1900’s. Then a detailed review of the current ASCE 7-05 Analytical Procedure design provisions is completed. Specifically, this report focuses on mid-rise structures 60 feet to 180 feet in height, located in the Midwest region of the United States. Following this in depth review of the ASCE 7 Standard, two studies are carried out. The studies were developed in order to assess the following two ideas: Have the wind load provisions become too complicated? Should there be a simplified procedure for mid-rise buildings?

Masonry walls are usually laid with the individual masonry units along a course overlapping units in the course below. Commonly, the perpend joints in the course occur above the mid-points of the units below to form a ‘half-bond’ or above a third point to form a ‘third-bond’. The amount of this overlap has a profound influence on the strength of a wall supported on three or four sides, where lateral pressures from wind cause combined vertical and horizontal flexure. Where masonry units are laid with mortar joints, the torsional shear bond resistance between the mortar and overlapping units largely determines the horizontal flexural strength. If there is zero bond strength between units, then the horizontal flexural strength is derived from the frictional resistance to torsion on the overlapping bed-faces of the units. This thesis reports a theoretical and experimental investigation into the frictional properties of overlapping units when subjected to combinations of vertical and horizontal moments and vertical axial compression. These basic properties were used to develop a theory to predict the lateral strength of walls supported on two, three or four sides. A plastic theory of behaviour was confirmed by experiment. The theory was then used to determine maximum unbraced panel sizes for particular boundary conditions. Design charts were developed to determine temporary bracing requirements for panels during construction.

abstract: Buildings and other structures, all components and cladding thereof, shall be designed and constructed to resist the wind loads are required in all wind codes. Simple quasi-static treatment of wind loads, which is universally applied to design of low to medium-rise structures, can be either overly conservative or erroneous under-estimated for design of high-rise structures. Dynamic response, vortex, wind directionality, and shedding from other structures are all complicated key factors suppose to be considered in design. Meanwhile, wind tunnel testing is expansive, difficult and sometimes inaccurate even if it is a widely used method in simulation of aerodynamic response. Computational Fluid dynamics (CFD), historically, were two-dimensional (2D) method using conformal transformations of the flow about a cylinder to the flow about an airfoil were developed in the 1930s. A number of three-dimensional (3D) codes were developed, leading to numerous commercial packages, which is more accessible and economical for wind load analysis. / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2014

Unsteady large-scale vortices, formed by the roll-up of free shear layers separating along sharp edges, are the dominant flow characteristics of the turbulent flow over buildings. These vortical structures interact with each other and with the building surface resulting in secondary separation and severe pressure fluctuations. Moreover, the interaction of the large-scale vortices with the multiplicity of turbulence scales in the incoming wind exacerbates their unsteady motion and hence significantly affects the pressure fluctuations spectra experienced by the building. Large-eddy simulations are conducted to study the interaction of homogeneous turbulence in the incident flow with a surface-mounted prism. A compact fifth-order upwind difference scheme is used to effectively and accurately perform the simulations. Three cases of incident flow are considered. In one case, the prism is placed in a smooth uniform flow. In the second case, homogeneous isotropic turbulence with von Karman spectrum is superimposed on the uniform flow at the inflow boundary. The integral length scale is one-half the prism height. In the third case, the integral length scale is equal to the prism height. The numerical results are compared with experimental measurements reported by Tieleman et al. (2002). The results show that the highest negative mean value of the pressure coefficient on the roof and the sides is about 30% larger in case two of turbulent inflow and takes place closer to the windward edge of the prism. Moreover, the pressure coefficients on the roof and sides of the prism in the case of turbulent inflow show a higher level of variations in comparison with the case of smooth inflow conditions. The predicted mean characteristics of the pressure coefficients in the turbulent case match the experimental values in terms of both magnitude and location on the roof of the prism reported in Tieleman et al. (1998) and Tieleman et al. (2002). As for the peak value, the peak value of -2 obtained in the turbulent inflow case two is about 20% smaller than the values measured experimentally by Tieleman et al. (2002). On the other hand, it is stressed that the peak value in the simulations would increase as the duration of the simulation is increased to match that of the experimental measurement. The results also show that the turbulent case yields a non-exceedence probability for the peak pressure coefficient that is closer to the one obtained from the measured data than the smooth case data. Also, spectral and cross-spectral analysis are carried out using complex Morlet wavelet transform to investigate pressure-velocity relation. The study shows that the nonlinearity in the relationship of velocity-pressure is detected using wavelet bicoherence. / Ph. D.

An analytical modal response tool was developed to investigate the characteristics of and to estimate static and dynamic launch vehicle responses to ground wind loads (GWL). The motivation of this study was to estimate the magnitude of response of the Ares I-X launch vehicle to ground winds and wind-induced oscillation (WIO) during roll-out and on the pad. This method can be extended to other launch vehicle designs or structures that possess a nearly cylindrical cross-section. Presented in this thesis is an overview of the theory used, a comparison of the theory with wind tunnel data, further investigation of the data to support the assumptions used within the analysis, and a prediction of the full-scale Ares I-X response. Additionally, an analytical investigation is presented that estimates the effect of atmospheric turbulence on WIO response. Most of the wind tunnel data presented in this report is taken from the GWL Checkout Model tested in the NASA Langley Transonic Dynamics Tunnel (TDT) in April 2007. The objective of the GWL Checkout Model was to reestablish and evaluate the capability of the facility to conduct GWL testing and to operate the associated equipment. This wind tunnel test was not necessarily intended to predict the full scale Ares vehicle response to GWL; however, it can be used to help validate the newly developed analytical method described in this thesis. A detailed GWL test incorporating updated vehicle designs and launch pad configurations of the Ares I-X flight test vehicle was also conducted in the TDT during the fall of 2008. This test provides more accurate predictions of the second bending mode response of the Ares I-X, and it models effects of the nearby tower and support structures. The proposed analytical method is also compared to select data from the Ares I-X GWL test; however, it is presented as normalized values to protect the sensitivity of the data. Results of the proposed analytical method show reasonable correlation to wind tunnel data. Also, this method was the first to determine that second bending mode WIO response was not only possible for the Ares I-X, but will also produce the most critical loads. Finally, an explanation is offered in this thesis regarding discrepancies between wind tunnel and full-scale WIO response data. / Master of Science

Eight roughness configurations in Clemson boundary layer wind tunnel are presented. For these configurations, flow parameters such as turbulent intensities, integral length scales, large- and small- scale turbulence, and spectra of velocity components of the wind are obtained and studied to the simulated turbulence. At the same time, new analyzing tools, orthogonal wavelet techniques, are applied to provide additional information in time domain. This makes it possible to study the intermittency event, one important characteristic associated with pressure peak activities in turbulence. Three parameters, scale energy, intermittency factor and intermittency energy are defined. Variation of these quantities as a result of different configuration is discussed. Finally, the corresponding variations in measured pressure peaks in relation with the variations of configuration as well as with the intermittency parameters are investigated. The work here is of important significance for future wind tunnel and field data comparison, and this could help to find the best simulation among all configurations. / Master of Science

Os silos metálicos cilíndricos de chapa corrugada e cobertura cônica são as unidades mais utilizadas no Brasil para o armazenamento de produtos granulares. As principais ações variáveis que atuam sobre os silos são as pressões devidas aos produtos armazenados e ao vento, sendo esta ação crítica quando o silo se encontra vazio. Devido à grande eficiência estrutural da forma cilíndrica e à resistência elevada do aço, estas estruturas são leves e delgadas e, portanto, suscetíveis a perdas de estabilidade local e global e arrancamento. Com a finalidade de avaliar estes efeitos foram realizados estudos teóricos e experimentais sobre as ações do vento em silos. O trabalho foi desenvolvido com ensaios de modelos aerodinâmicos e aeroelásticos em um túnel de vento na Universidade de Cranfield, Inglaterra, com o objetivo de determinar os coeficientes aerodinâmicos no costado e na cobertura. Os resultados mostram que os valores dos coeficientes recomendados pela Norma Brasileira de vento, NBR 6123 (1990), são adequados para o costado. Para a cobertura cônica, como não são especificados pela NBR, são recomendados valores dos coeficientes aerodinâmicos determinados nos ensaios. Conclui-se também que a colocação externa das colunas é a favor da segurança e que o uso de anéis enrijecedores no costado é indicado e muito importante para a estabilidade local e global da estrutura do silo. / The steel cylindrical silos made of corrugated sheets with conical roofs are the most used units to the storage of granular materials. The main silo loads are the pressures due to the stored material and to the wind, being this action the critical one when the silo is empty. Due to the high efficiency of the cylindrical form and to the high strength of the steel, these structures are thin and light-weight and, as a consequence, susceptible to the loss of local and global stability and to the pull out of the structure. With the aim to assess these effects related to the wind loading in silos, some theoretical and experimental studies were conducted. The work was carried out with aerodynamic and aeroelastic models tested in a boundary layer wind tunnel in the University of Cranfield, England, with the objective to determine the aerodynamic coefficients of the cylinder and the conical roof. The results show that the coefficients of the Brazilian Code of wind loads, NBR 6123 (1990), are adequate to the cylinder. The coefficients to the conical roof are suggested based on our tests, considering that there are no values specified by the NBR. As well it is concluded that the outside columns is on the side of safety and it is indicated the use of wind rings attached to the cylinder, which are very important to the local and global stability of the silo structure.

Symmetrical steel moment frames that are subjected to sidesway forces due to unsymmetrical live loads will undergo sidesway. The P-delta effects on a moment frame under the influence of sidesway forces is studied. The effective length method is used for the second-order analysis specified in the American Institute Steel Construction - Load and Resistance Factor Design (AISC-LRFD). This study investigates the P-delta effects on a multi-story, multi-bay steel moment frame subjected to sidesway forces caused by various unsymmetrical live load patterns. The study focuses on the interaction of axial and bending moment in the columns. The actual response of a moment frame is estimated by amplifying the results of a first-order elastic analysis using moment magnification factors. The moment magnification factors for each story of the steel moment frame are summarized.