The Buckling Restrained Braced Frame (BRBF) is used in steel structures as a lateral load resisting system for seismic events. In typical design procedure the impact of gravity loads acting on BRBFs is neglected and the beams and columns of the structure are designed to resist all gravity loads. In actuality BRBFs are supporting portions of gravity loads acting on the structure which may be changing the overall performance of BRBFs. The purpose of this study is to determine the impact of large gravity loads on BRBF performance. This is done using finite element analysis to test two different structures supporting large gravity loads. The first structure is a seven story structure consisting of different BRBF configurations; the second structure is a three story structure with all BRBFs in an eccentrically braced configuration. Each structure was modeled with applied ground motion simulations with and without gravity loads, and with gravity loads but no applied ground motion simulations. Results indicate that gravity loads have no significant impact on the overall performance of BRBFs for either structure.

Approximately one-third of U.S. adults are at increased risk for life-threatening diseases such as atherosclerosis and type 2 diabetes mellitus. Such individuals are considered healthy without any diagnosed cardiometabolic conditions but may have a constellation of cardiometabolic complications that include obesity, glucose intolerance, hyperinsulinemia, dyslipidemia, hypertension, insulin resistance, and hypertriglyceridemia. When most of these preclinical conditions comorbidly occur, the condition has been referred to as metabolic syndrome (MetS). MetS is considered to reflect one or more early pathophysiological processes in cardiometabolic disease; however, the extent to which these complications and their underlying pathophysiology interact with behavioral factors such as stress, diet, and physical activity have not been clearly established. For example, diet consisting of high total caloric intake and high fat composition is posited to contribute to obesity and other cardiometabolic risk factors, but research is inconsistent regarding the effect of psychological distress (i.e., anxiety, stress, depression, anger) on dietary intake and whether dietary intake mediates a relationship between distress and preclinical cardiometabolic disease risk. One factor that has been suggested to play a role in the distress – dietary intake relationship is eating style. Research on eating styles has identified four main types that may be related to distress and dietary intake: restrained, disinhibited, emotional, and external eating. Restrained eaters consciously restrict food intake to control body weight and body shape. Disinhibited eating refers to overeating that occurs following failure of restraint. Emotional eaters consume foods to reduce and alleviate negative emotions, such as anxiety. External eating occurs in response to immediate food-related external stimuli, regardless of internal physiological cues of hunger. Current evidence suggests each of these eating styles moderates the relationship between distress and dietary intake. There is also some research to suggest a relationship between eating styles and weight gain, body mass index (BMI), and development of obesity. However, no study has examined the interrelationships among psychological distress, eating style, and central obesity, and whether these relationships differ according to gender. Moreover, the extent to which distress and eating style may be associated with cardiometabolic risk beyond obesity is unknown. Thus, the main aim of the present study was to test a model of mediation and moderation to evaluate how psychological distress, eating styles, dietary intake, and gender are associated with measures of cardiometabolic risk in healthy individuals (Figure 1). Four hundred sixty-four participants contributed data from two different studies: Obesity, Metabolic Syndrome, and Meal-Related Glycemia (SUGAR) and Markers Assessing Risk for Cardiovascular Health (MARCH). All participants were aged 18-55 years, had no major systemic disease, were not using medications having a cardiovascular, carbohydrate, endocrine, or psychiatric effect, and had no history of substance or alcohol abuse or dependence. The study employed a structural equation modeling (SEM) approach to assess the following aims: 1) to develop composite, latent factors to reflect psychological distress, eating style, and dietary intake using confirmatory factor analysis (CFA) and to develop a hybrid model of cardiometabolic risk; and 2) to simultaneously test the interrelationships among factors in a comprehensive model so that the strength of direct and indirect effects can be evaluated while statistically controlling for the other factors and covariates in the model. Latent factor models of psychological distress and eating style fit the data and were statistically acceptable, and a hybrid model of cardiometabolic risk fit the data and its CFA components were acceptable. A latent factor model of dietary intake would have likely fit the data and been statistically acceptable given the high intercorrelations among dietary variables, but no such factor was created because dietary variables failed to confirm the hypothesized associations with other model components (e.g., waist girth, eating styles); thus, these measures were excluded from further SEM analyses. Final model results showed that psychological distress was positively related to restrained, emotional, and external eating styles, but only restrained eating was directly associated with greater waist girth. Distress was not directly related to cardiometabolic risk, but an indirect effect was found in which higher levels of distress led to greater waist girth via higher levels of restrained eating. Waist girth, in turn, served as a significant mediator between restrained eating and worse insulin sensitivity, higher blood pressure, diminished glucose tolerance, and greater dyslipidemia. These effects were significant when controlling for age, gender, education, and physical activity, and when analyzed in a comprehensive SEM model simultaneously including distress, eating style, and cardiometabolic risk variables. Of note, results suggest the possibility for a reversed effect such that waist girth leads to restrained eating. Findings also suggest that emotional eating may lead to distress. In contrast, the relationship between distress and the other two eating styles, restrained and external eating, appeared unidirectional such that distress leads to restrained and external eating but not the reverse. Future studies using longitudinal data are needed to better understand these relationships in regards to causality. Data from the MARCH subsample was excluded from the above final modeling analyses because eating style data were only available for the SUGAR subsample. Thus, the role of gender in how distress, eating styles, and cardiometabolic risk are interrelated could not be examined due to the small number of women in the SUGAR study (n = 38). It remains unknown whether the significant effect of distress on each of the eating styles found in the current study was driven primarily by men, women, or both equally. Similarly, the sample size would not permit the evaluation of whether gender moderated the effect of restrained eating on central obesity. Given that women in the current study reported more restrained, emotional, and external eating than men, future studies with larger samples should follow-up by assessing for potential moderating effects of gender. The present findings suggest that decreasing restrained eating style may lead to less central fat deposition and hence reduced cardiometabolic risk. Such “non-diet” interventions show potential for improved cardiometabolic health, but more research is needed. Particularly needed are studies examining prevention and intervention outcomes based on type of restrained eating – flexible versus rigid – to better understand how these different subtypes operate and how they can be altered effectively to improve health.

A typical buckling restrained brace (BRB) consists of a core segment and a buckling restraining mechanism. When compared to a conventional brace, BRBs provide nearly equal axial yield force in tension and compression. Buckling restraining mechanism can be grouped into two main categories. Buckling is inhibited either by using a concrete or mortar filled steel tube or by using steel sections only. While a large body of knowledge exists on buckling restrained braces the behavior of steel encased BRBs has not been studied in detail. Another area that needs further investigation is the detailing of the deboding material. For all types of BRBs a debonding material or a gap has to be utilized between the core brace and the restraining mechanism. The main function of the debonding material is to eliminate the transfer of shear force between the core brace and the restraining mechanism by preventing or reducing the friction. A two phase research study has been undertaken to address these research needs. In the first phase an experimental study was carried out to investigate the potential of using steel encased BRBs. In the second phase a numerical study was conducted to study the friction problem in BRBs. The experimental study revealed that steel encased braces provide stable hysteretic behavior and can be an alternative to mortar filled steel tubes. Material and geometric properties of the debonding layer for desired axial load behavior were identified and presented herein.

The mass media project a thin “ideal” female body type (ideal-body media; IBM) onto young women. Sociocultural theorists propose that, through processes of internalisation and social comparison, IBM-exposure promotes negative body satisfaction and unhealthy eating behaviour. In three experiments, I investigated how IBM-exposure affected restrained eaters. Restrained eaters are women who are trying to lose weight by attempting to restrict their food intake. Previous researchers have found that restrained eaters perceive and process body-related information more readily than others do. The literature surrounding restrained eaters’ IBM-related self-evaluations and food intake is inconsistent. Some researchers have found restrained eaters to report positive self-evaluative effects and others have not. Furthermore, the majority of researchers report that viewing IBM triggers restrained eaters’ eating. However, this effect is not always replicated and this might be because restrained eaters have been identified with different restraint scales. To test this idea, I used two conceptually different dietary restraint scales throughout the current experiments: the concern for dieting subscale of the Restraint Scale (RS-CD) and the Dietary Intent Scale (DIS). Furthermore, because some researchers have argued that participants within previous (non-restraint) studies reported negative IBM-effects because they thought that they were meant to be negatively affected (i.e., demand characteristics), reducing these demands was a focus throughout the current experiments. In Study 1, demand characteristics were minimised by employing implicit outcome measures and by incorporating a two-study pre-text to separate the experimental manipulation from the explicitly measured dependent variables. Under the guise of a hunger and memory study, restrained and unrestrained eaters (N = 107) were required to concentrate on a slideshow of IBM- or Control-images for 2-minutes and complete an associated memory test (i.e., advertent attention). Restrained eaters (RS-CD and DIS) exposed to IBM reported negative effects (e.g., mood). However, IBM-exposure did not trigger their food intake in an unrelated taste test with M&Ms. I interpreted these findings alongside control theory. This is the theory that goal-related negative affect encourages increased goal-performance. I reasoned that paying advertent attention to the IBM caused goal-related negative affect, which triggered goal effort (i.e., dietary restraint). This theory was further tested in Study 2. The same manipulation was used in Study 2 (N = 268), which was touted as a study about participants’ personality and task performance. Here, I aimed to test restrained eaters’ implicit approach and avoidance tendencies toward diet and food stimuli. Therefore, a joystick lexical decision task (LDT) was used instead of a taste test. Restrained eaters’ self-evaluations (e.g., self-esteem) were not significantly affected by being in different experimental conditions. However, restrained eaters (RS-CD) in the IBM-condition avoided high-calorie food words during the LDT significantly faster than other participants did. These results (Studies 1 and 2) differed from previous research. This difference was attributed to the high level of advertent attention participants paid to the IBM in my experiments. Therefore, in Study 3, I manipulated participants’ attention levels. Participants (N = 171) were made to believe that the experimental slideshow and LDT were part of a task performance study. Although participants who were assigned to the Inadvertent- and Advertent-Attention conditions were exposed to the same slideshow (IBM- or Neutral-images), the experimenter did not ask participants in the Inadvertent-condition to focus on the slideshow. After this experimental manipulation, participants completed the joystick LDT. Subsequently, they completed a second unrelated study about personality and the five human senses (e.g., taste, touch, etcetera). All participants were randomly assigned to the taste-condition and completed a taste test. Inconsistent with my previous results, I did not obtain significant self-evaluation or LDT results. Furthermore, restrained eaters (RS-CD) who paid advertent attention to the IBM consumed more food than others consumed during the taste test. In comparison, restrained eaters were buffered from this effect if they had paid inadvertent attention to the IBM-images. When comparing these (nonsignificant and significant) results with previous research, it seems that restrained eaters’ IBM-responses are highly specific to environmental and/or experimental settings. I developed a preliminary theory to predict restrained eaters’ behaviour. This theory takes into account participants’ restraint status, restraint success, IBM-related attention and their eating-related attention.

Στόχος της εργασίας είναι η παραμετρική μελέτη μεταλλικών τρισδιάστατων πλαισίων με συνδέσμους δυσκαμψίας, ανθεκτικούς σε λυγισμό (BRB: Buckling Restrained Braces). Τα πρώτα κεφάλαια της εργασίας αποτελούν το θεωρητικό υπόβαθρο της διατριβής και αναφέρονται στα ζητήματα που αφορούν τον αντισεισμικό σχεδιασμό των μεταλλικών κατασκευών. Στο υπόβαθρο αυτό βασίστηκε τόσο ο σχεδιασμός του δείγματος των κατασκευών όσο και η επιλογή των υπό διερεύνηση παραμέτρων. Το αντικείμενο της εργασίας καθαυτό παρουσιάζεται στα τρία τελευταία κεφάλαια όπου γίνεται η περιγραφή του σχεδιασμού των τελικών κτιρίων ώστε να επιτευχθεί φυσική μονοαξονική εκκεντρότητα και στη συνέχεια η ανάλυση των κατασκευών αυτών με μη γραμμικές αναλύσεις. Από αυτές δημιουργείται μια βάση δεδομένων από την οποία εξάγονται συμπεράσματα που αφορούν τη συσχέτιση της εκκεντρότητας με τα μεγέθη απόκρισης των κατασκευών. / The subject of this thesis is the non linear analysis of 3D steel frames with buckling restrained braces (BRB).

The objective of this study was to numerically investigate the effects of slenderness ratios and end rotational restraints on the post-buckling behavior of non-sway columns. To study the effect of end restraints, numerical solutions were generated for three different support conditions, namely, hinged-hinged, fixed-hinged and fixed-fixed. Furthermore, for each of these support conditions, the effects of slenderness ratios on the post-buckling response were analyzed by considering the slenderness ratios of 50,125 and 200. Based on the numerical data presented in this thesis, the following conclusions can be made.  The unrestrained columns under mechanical loads do not exhibit any significant post-buckling strength.  Restrained Columns subjected to thermal loading undergo significantly smaller deformations in contrast to unrestrained columns, where deformations are relatively larger as the loads are increased only slightly above their critical levels.  The mechanical post-buckling response does not seem to depend on the slenderness ratios of the columns ;whereas the thermal post-buckling response depends on the slenderness ratios of the columns with the relative deformation decreasing with slenderness ratio at a given temperature ratio.  Post buckling behavior of columns subjected to mechanical loadings does not seem to change when the rotational restraints are added whereas in case of columns subjected to thermal loading, the post-buckling response depends on the rotational restraints at the ends of the column. o For a constant slenderness ratio, the deflection ratio was found out to be the smallest for the hinged-hinged column and largest for the fixed-fixed column subjected to thermal loads at a given temperature ratio.

O presente estudo analisa a demanda reprimida às ações e aos serviços de saúde de média complexidade no município de Campos dos Goytacazes/ RJ, sob a ótica do acesso incompleto. Optamos pela dialética como método de investigação, compreendendo nosso objeto dentro de um contexto histórico permeado de contradições e complexidades, considerando a dinâmica da realidade social. Realizamos entrevistas semi-estruturadas com os seguintes sujeitos: coordenadora do ambulatório; usuários com demanda reprimida, a partir do acesso incompleto às ações de serviços de saúde; marcadores de consulta dos Postos de Saúde e Programa de Saúde da Família e as assistentes sociais do Hospital Geral de Guarus. Os entrevistados somam informações importantes acerca da temática estudada trazendo diferentes enfoques para uma análise mais aproximada da demanda reprimida, entendida como síntese de múltiplas determinações. Identificamos e confirmamos a existência de dois tipos de acesso incompleto no nível de média complexidade: aquele que ocorre na passagem da baixa para a média complexidade e aquele que se dá dentro do próprio nível da média complexidade. Ficou evidente que a demanda reprimida, apesar de permear todo o sistema de saúde, não é colocada no centro das preocupações e debates pelas instâncias que a vivenciam direta ou indiretamente profissionais de saúde envolvidos, gestores e gerentes e ainda conselhos de saúde. Assim, confirmamos nossa hipótese, referente à falta de visibilidade da demanda reprimida, ocasionada pelo acesso incompleto na média complexidade e a não delimitação desta demanda como preocupação central nas ações dos assistentes sociais. O estudo mostrou como o acesso se constitui de forma incompleta, ao longo do percurso realizado pelo usuário, no nível de média complexidade, configurando desse modo, uma demanda reprimida significativa. Este estudo evidenciou ainda que, para além do financiamento, isto é, dos recursos necessários para ampliar o acesso dos usuários às ações e aos serviços de saúde, existem questões que dizem respeito à organização e programação das ações, nos domínios do planejamento e da gestão do SUS, perpassando pela transparência na definição de vagas e pela responsabilização do poder público na consolidação da gestão colegiada e do controle social. Essas questões precisam ser enfrentadas e compartilhadas entre - gestores, planejadores, profissionais de saúde e usuários - em busca da EFETIVAÇÃO do sistema único de saúde com acesso universal e com controle social. / The present study analyzes the restrained demand to the actions and the services of health of average complexity in the city of Campos dos Goytacazes/RJ, about the optics of the incomplete access. We opt to dialectic as inquiry method, understanding our object in a historical context replete of contradictions and complexities, considering the dynamics of the social reality. We carry through interviews half-structuralized with the following citizens: coordinator of the clinic; users with restrained demand, from the incomplete access to the actions of health services; markers of consultation of the Ranks of Health and Program of Health of the Family and the social assistants of the General Hospital of Guarus. The interviewed ones add important information concerning the thematic one more studied bringing different views for an approached analysis of the restrained demand, understood as synthesis of multiple determinations. We identify and confirm the existence of two types of incomplete access in the level of average complexity: that one that occurs in the ticket of the low one for the average complexity and that one that if gives inside of the proper level of the average complexity. It was evident that the restrained demand, although to be present in the health system all, is not placed in the center of the concerns and debates for the instances that live deeply it directly or indirectly - professional of health involved, managing and controlling and still health advice. Thus, we confirm our hypothesis, referring to the lack of visibility of the restrained demand, caused for the incomplete access in the average complexity and not the delimitation of this demand as central concern in the actions of the social assistants. The study it showed as the access if it constitutes of incomplete form, to the long one of the passage carried through for the user, in the level of average complexity, configuring in this way, a restrained demand significant. This study still evidenced that, for beyond the financing, that is, of the resources necessary to extend the access of the users to the actions and the services of health, questions that issue about the organization and programming of the actions, in the around of the planning and the management of the SUS, passing for the transparency in the vacant definition and for the responsibility of the power public in the consolidation of the management student body and the social control. These questions need to be faced and to be shared between - managers, planners, professionals of health and users - in search to become an effective unique system of health with universal access and social control.

O presente estudo analisa a demanda reprimida às ações e aos serviços de saúde de média complexidade no município de Campos dos Goytacazes/ RJ, sob a ótica do acesso incompleto. Optamos pela dialética como método de investigação, compreendendo nosso objeto dentro de um contexto histórico permeado de contradições e complexidades, considerando a dinâmica da realidade social. Realizamos entrevistas semi-estruturadas com os seguintes sujeitos: coordenadora do ambulatório; usuários com demanda reprimida, a partir do acesso incompleto às ações de serviços de saúde; marcadores de consulta dos Postos de Saúde e Programa de Saúde da Família e as assistentes sociais do Hospital Geral de Guarus. Os entrevistados somam informações importantes acerca da temática estudada trazendo diferentes enfoques para uma análise mais aproximada da demanda reprimida, entendida como síntese de múltiplas determinações. Identificamos e confirmamos a existência de dois tipos de acesso incompleto no nível de média complexidade: aquele que ocorre na passagem da baixa para a média complexidade e aquele que se dá dentro do próprio nível da média complexidade. Ficou evidente que a demanda reprimida, apesar de permear todo o sistema de saúde, não é colocada no centro das preocupações e debates pelas instâncias que a vivenciam direta ou indiretamente profissionais de saúde envolvidos, gestores e gerentes e ainda conselhos de saúde. Assim, confirmamos nossa hipótese, referente à falta de visibilidade da demanda reprimida, ocasionada pelo acesso incompleto na média complexidade e a não delimitação desta demanda como preocupação central nas ações dos assistentes sociais. O estudo mostrou como o acesso se constitui de forma incompleta, ao longo do percurso realizado pelo usuário, no nível de média complexidade, configurando desse modo, uma demanda reprimida significativa. Este estudo evidenciou ainda que, para além do financiamento, isto é, dos recursos necessários para ampliar o acesso dos usuários às ações e aos serviços de saúde, existem questões que dizem respeito à organização e programação das ações, nos domínios do planejamento e da gestão do SUS, perpassando pela transparência na definição de vagas e pela responsabilização do poder público na consolidação da gestão colegiada e do controle social. Essas questões precisam ser enfrentadas e compartilhadas entre - gestores, planejadores, profissionais de saúde e usuários - em busca da EFETIVAÇÃO do sistema único de saúde com acesso universal e com controle social. / The present study analyzes the restrained demand to the actions and the services of health of average complexity in the city of Campos dos Goytacazes/RJ, about the optics of the incomplete access. We opt to dialectic as inquiry method, understanding our object in a historical context replete of contradictions and complexities, considering the dynamics of the social reality. We carry through interviews half-structuralized with the following citizens: coordinator of the clinic; users with restrained demand, from the incomplete access to the actions of health services; markers of consultation of the Ranks of Health and Program of Health of the Family and the social assistants of the General Hospital of Guarus. The interviewed ones add important information concerning the thematic one more studied bringing different views for an approached analysis of the restrained demand, understood as synthesis of multiple determinations. We identify and confirm the existence of two types of incomplete access in the level of average complexity: that one that occurs in the ticket of the low one for the average complexity and that one that if gives inside of the proper level of the average complexity. It was evident that the restrained demand, although to be present in the health system all, is not placed in the center of the concerns and debates for the instances that live deeply it directly or indirectly - professional of health involved, managing and controlling and still health advice. Thus, we confirm our hypothesis, referring to the lack of visibility of the restrained demand, caused for the incomplete access in the average complexity and not the delimitation of this demand as central concern in the actions of the social assistants. The study it showed as the access if it constitutes of incomplete form, to the long one of the passage carried through for the user, in the level of average complexity, configuring in this way, a restrained demand significant. This study still evidenced that, for beyond the financing, that is, of the resources necessary to extend the access of the users to the actions and the services of health, questions that issue about the organization and programming of the actions, in the around of the planning and the management of the SUS, passing for the transparency in the vacant definition and for the responsibility of the power public in the consolidation of the management student body and the social control. These questions need to be faced and to be shared between - managers, planners, professionals of health and users - in search to become an effective unique system of health with universal access and social control.

Reinforced concrete frame buildings designed and built prior to the enactment of modern seismic codes of the pre-1970’s era are considered seismically vulnerable, particularly when they are subjected to strong ground motions. It is the objective of this research to develop a new and innovative seismic retrofit technology for seismic upgrading of nonductile or limited ductility reinforced concrete frame buildings involving the implementation of buckling restrained braces. To achieve this objective, combined experimental and analytical research was conducted. The experimental research involved tests of large-scales reinforced concrete frames under slowly applied lateral deformation reversals, and the analytical research involved design and nonlinear analysis of laboratory specimens, as well as design and dynamic inelastic response history analysis of selected prototype buildings in eastern and western Canada. The research project started with a comprehensive review of the building code development in Canada to assess the progression of seismic design requirements over the years, and to select a representative period within which a significant number of engineered buildings were designed and constructed with seismic deficiencies. A similar review of seismic design and detailing provisions of the Canadian Standard Association (CSA) Standard A23.3 on Design of Concrete Structures was also conducted for the same purpose. Six-storey and ten-storey prototype buildings were designed for Ottawa and Vancouver, using the seismic provisions of the 1965 National Building Code of Canada, representative of buildings in eastern and western Canadian. Preliminary static and dynamic linear elastic analyses were performed to assess the effectiveness of upgrading the ten-storey reinforced concrete building designed for Ottawa. The retrofit methods studied consisted of lateral bracing by adding reinforced concrete shear walls, diagonal steel braces, or diagonal steel cable strands. The results indicated that the retrofit techniques are effective in limiting deformations in non-ductile frame elements to the elastic range. The numerical analyses were used to demonstrate the effectiveness of Buckling Restrained Braces (BRBs) as a retrofit method for seismically deficient reinforced concrete frame buildings. The experimental phase of research consisted of two, 2/3rd scale, single bay and single storey reinforced concrete frames, designed and constructed based on a prototype sixstorey moment resisting frame building located in Ottawa and Vancouver, following the requirements of the 1965 edition of the NBCC. One test specimen served as a bare control frame (BCF) that was first tested, repaired and retrofitted (RRF) to evaluate the effectiveness of the proposed retrofit methodology for buildings subjected to earthquakes in the City of Ottawa. The control frame was assessed to be seismically deficient. The second frame served as a companion non-damaged frame (RF) that was retrofitted with a similar retrofit concept but for buildings subjected to earthquakes in the City of Vancouver. A new buckling restrained brace (BRB) was conceived and developed to retrofit existing sub-standard reinforced concrete frames against seismic actions. The new BRB consists of a ductile inner steel core and an outer circular sleeve that encompasses two circular steel sections of different diameters to provide lateral restraint against buckling in compression of inner steel core. Mortar is placed between the two circular sections to provide additional buckling resistance. The inner core is connected to novel end units that allow extension and contraction during tension-compression cycles under seismic loading while providing lateral restraint against buckling within the end zones. The end units constitute an original contribution to the design of Buckling Restrained Braces (BRBs), providing continuous lateral restraint along the core bar. The new technique has been verified experimentally by testing four BRBs on the two test structures under simulated seismic loading. The test results of the BRB retrofitted frames indicate promising seismic performance, with substantial increases in the lateral load and displacement ductility capacities by factors of up to 3.9 and 2.6, respectively. In addition, the test results demonstrate that the BRB technology can provide excellent drift control, increased stiffness, and significant energy dissipation, while the reinforced concrete frames continue fulfilling their function as gravity load carrying frames. The above development was further verified by an exhaustive analytical study using SAP2000. At the onset, analyses were conducted to calibrate and verify the analytical models. Two-dimensional, one-bay, one-storey models, simulating the BCF and RRF test frames, were created. The models were subjected to incrementally increasing lateral displacement reversals in nonlinear static pushover analyses, and the results were compared with those obtained in the test program. Material nonlinearity was modeled using “Links” to incorporate all lumped linear and nonlinear properties that were defined with moment-rotation properties for flexural frame members and with force-displacement properties for the diagonal buckling restrained braces. Comparison with test data demonstrated good agreement of the frame behaviour in the elastic and post-elastic ranges, and the loading and unloading stiffness. The research program was further augmented with nonlinear dynamic time history analyses to verify the feasibility of the new retrofit technique in multi-storey reinforced concrete frame buildings located in Canada and their performances relative to the performance-based design objectives stated in current codes. Prior to conducting the analyses, 450 artificial earthquake records were studied to select the best matches to the Uniform Hazard Spectra (UHS) according to the 2010 edition of the NBCC for Ottawa and Vancouver. Furthermore, additional analyses were conducted on buildings for the City of Ottawa based on amplified Uniform Hazard Spectrum compatible earthquake records. The nonlinear time-history response analyses were conducted using a model that permits inelasticity in both the frame elements and the BRBs.The results indicated that reinforced concrete buildings built before the 1970’s in the City of Ottawa do not require seismic retrofitting; they remain within the elastic range under current code-compatible earthquake records. The structural building performance is within the Immediate Occupancy level, and all structural elements have capacities greater than the force demands. In the City of Vancouver, buildings in their virgin state experienced maximum interstorey drifts of 2.3%, which is within the Collapse Prevention structural performance level. Improved building performance was realized by retrofitting the exterior frames with multiple uses of the BRB developed in this research project. The seismic shear demands were reduced in the columns, while limiting the deformations in the non-ductile frame elements to the elastic range. The lateral interstorey drift was limited to 0.92%, which lies within the Life Safety structural performance level.

This thesis presents the development of a design procedure for buckling-restrained braced frames (BRBF's). This procedure uses nonlinear time history analysis and a formal optimization algorithm. The time history analysis includes an elasto-plastic model for the braces. The optimization algorithm is a genetic algorithm. This procedure is referred to throughout the thesis as the "Nonlinear Time History Analysis Procedure with Optimization" (NTHO). Current design specifications for BRBF's are based on inelastic design spectra and approximate formulas for the determination of natural period. These spectra are used to obtain seismic base shear, and the distribution of equivalent lateral forces. Yielding and drift criteria are then used to determine brace areas. This design procedure is referred to throughout the thesis as the "Equivalent Lateral Force Procedure" (ELF). The thesis compares results from the NTHO and ELF procedures for a variety of BRBF's and levels of seismicity. The ELF procedure is judged against the more accurate NTHO procedure, and BRBF's are identified where the ELF procedure produces unconservative and excessively conservative designs. Since the NTHO procedure is more computationally expensive than the ELF procedure, design charts are developed for quickly sizing brace areas for a variety of BRBF's based on the NTHO procedure. Among the conclusions at the end of the thesis is the surprising result that the design charts show a near linear variation of brace area from story to story.