The aerospace industry endeavours to improve modern aircraft capabilities in efficiency, endurance, and comfort. One means of achieving these goals is through new enhancements in aerodynamics. Increased wing aspect ratio is an example of further improving efficiency. However, this comes with new challenges including possibly adverse aero-elastic and aero-servo-elastic (ASE) phenomena. New computational methods and tools are emerging and there is a need for experimental data for validation. University of Victoria’s Centre for Aerospace Research (UVic CfAR) set out to design a 20kg ASE demonstrator using a remotely piloted aircraft (RPA). This aircraft was designed with the intent of exploring coupling between aero-elastic modes including coupling between the short period aerodynamic mode and the first out-of-plane elastic mode of the wing. This thesis discuses the implementation of instrumentation designed and integrated into the ASE RPA demonstrator to monitor the deformation of the elastic wing in-flight. A strain based measurement technique was selected for integration into the ASE aircraft. This choice was made for several reasons including its reliability regardless of outdoor lighting, relatively lightweight processing requirements for real time applications, and suitable sampling bandwidth. To compute the wing deformation from strain, a method, sometimes referred to as strain pattern analysis (SPA), utilizing linear combinations of reference modal shapes fit against the measured strain, was used. Although this method is not new, to the author’s knowledge, it is the first practical application to a reduced scale RPA demonstrator. The deformation measurement system was validated against a series of distributed static load tests on the ground. Distributed load cases along the wing demonstrated good out-of-plane measurement performance. A case where only load is applied near the root of the wing resulted in the largest error in part as the mode shapes generated are less suited to approximate the resulting shape. In general errors in out-of-plane displacement at the end of the flexible wing portion can be expected to be less than 5%. The displacement at the tip of the wing can be as great as 11% for the left wing whereas the right wing is 4.7%. This suggest an asymmetry between the left and right wings requiring specifically tuned FE models for each to achieve best results. Twist angles presented in tests were relatively small for accurate comparison against the reference measurement, which was relatively noisy. Generally, the deformation measurement by SPA technique followed the same twist behaviours as the reference. A twist case, unlikely to be seen in flight, provided some insight into twist measurement robustness. The work presented is merely a small step forward with many opportunities for further research. There is room for improvement of the FE model used to generate the mode shapes in the strain pattern analysis. Initial efforts focused on the flexible spar portion of the wing. With more work improvements could be achieved for the estimation of the rigid wing. Additionally, there was some asymmetry between each wing semi-span, and with some focus on the left wing its results could be improved to at least match that of the right wing. A real-time implementation was not completed and would be particularly interesting for use as feedback for flight control. Study of load alleviation techniques may benefit. Another topic of study is the combination of this method with other measurements, such as accelerometers, to provide improved performance state estimation through sensor fusion. / Graduate

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The Hampton Roads Bridge-Tunnel is one of the oldest prestressed concrete structures in the United States. The 3.5 mile long twin structure includes the world's first underwater tunnel between two man-made islands. Throughout its 60 years in service, the harsh environment along the Virginia coast has taken its toll on the main load carrying girders. Concrete spalling has exposed prestressing strands within the girders allowing corrosion to spread. Some of the more damaged girders have prestressing strands that have completely severed due to the extensive corrosion. The deterioration has caused select girders to fail the necessary load ratings. The structure acts as an evacuation route for the coast and is a main link for the local Norfolk Naval Base and surrounding industry. Because of these constraints, load posting is not a viable option. Live load testing of five spans was performed to investigate the behavior of the damaged spans. Innovative techniques were used during the load test including a wireless system to measure strains. Two different deflection systems were implemented on the spans, which were located about one mile offshore. The deflection data was later compared head to head. From the load test results, live load distribution factors were developed for both damaged and undamaged girders. The data was also used by the local Department of Transportation to validate computer models in an effort to help pass the load rating. Overall, this research was at the forefront of the residual strength of prestressed concrete girders and the testing of in-service bridges. / Master of Science

A presente pesquisa teve como objetivo principal a realização de estudos laboratoriais, de campo e numéricos, buscando viabilizar duas misturas de concreto permeável que foram utilizadas na construção de duas calçadas experimentais localizadas no campus da USP em São Paulo. Nas pistas experimentais foi realizado o acompanhamento da capacidade permeável ao longo do tempo, além da avaliação das suas respostas estruturais frente à aplicação de carregamentos dinâmicos por meio de equipamento FWD, considerando a variação do teor de umidade no interior das estruturas. Por fim, foram realizadas retroanálises com uso de diferentes softwares procurando entender qual das camadas da estrutura apresenta maior vulnerabilidade estrutural frente à presença de volumes excessivos de água. Os resultados da etapa laboratorial indicaram que há uma sensibilidade muito grande no comportamento das misturas em função do teor de aditivo superplastificante, uma vez que houve segregação severa da pasta de cimento no fundo dos corpos de prova quando esse teor ultrapassou determinado limite. Os resultados dos ensaios de taxa de infiltração em campo possibilitaram a proposição um modelo empírico para estimativa do desempenho da capacidade hidráulica para calçadas em concreto permeável executadas na região de São Paulo. Os resultados dos levantamentos deflectométricos e das retroanálises indicaram variação considerável na capacidade de suporte do conjunto base+subleito entre as calçadas, além de evidenciar considerável perda da capacidade de suporte dessas estruturas quanto submetidas à presença de elevados volumes de água no seu interior. Palavras chave: concreto permeável, calçada, pavimento, taxa de infiltração, levantamento deflectométrico, análise estrutural, retroanálise. / The main goal of this research was to carry out laboratorial, field and numerical studies with the purpose of defining two feasible pervious concrete mixtures to be used as the surface layer of two experimental sidewalks in the campus of the University of São Paulo. The permeability capacity of the sidewalks was monitored along time, as well as its structural responses in terms of deflections due to application of FWD dynamic loadings, assessing how the structural behavior was impacted by the presence of high volumes of water into the permeable structure. A backcalculation procedure was used in order to assess the elastic behavior of the structure layers, as well as find out which layer of the structure is the most vulnerable in terms of mechanical behavior under the presence of excessive volumes of water. The results in the laboratory indicates that pervious concrete mixtures are considerable sensitives to the amount of superplasticizer additive, since a severe mortar segregation was observed on the bottom of the specimens casted using some of the mixtures produced. The results of infiltration tests in field made it possible to develop an empirical model capable of estimating the hydraulic performance of pervious concrete permeable sidewalks in São Paulo region. The results of the deflection measurements and the backcalculations indicated a considerable variation on the bearing capacity of the infrastructure (base+subgrade) between the two sidewalks. In addition, it is evident the loss of bearing capacity of the structure under the presence of excessive amount of water into the sidewalk.