An experimental and analytical investigation was conducted to study the behavior of diagonal knee moment end-plate connections and a multiple row extended moment end-plate connection. Diagonal knee moment end-plate connections differ from typical moment end-plate connections because of the large pitch distance required between the top flange and first row of tension bolts. The large pitch distance is outside of the geometric parameters of all previous research. Design solutions are presented for five moment end-plate connections with provisions added to accommodate these parameters. The analytical investigation focused on the limit states of end-plate yielding and bolt rupture. Yield-line analysis was used to predicted end-plate yielding and a simplified Kennedy method proposed by Borgsmiller and Murray (1995) was used to predict bolt rupture including and excluding prying forces. An experimental investigation was conducted to verify the design solutions. Five knee area specimens and one plate girder specimen were tested in this study. The analytical and experimental results are analyzed and compared. For the test specimens that failed in the connection, the predicted results proved to be conservative. Recommendations are presented at the end of the study as well as sample calculations. / Master of Science

Experimental and analytical research has been conducted to develop unified design procedures for eight extended end-plate moment connection configurations subject to cyclic/seismic loading. In addition, the suitability of extended end-plate moment connections for use in seismic force resisting moment frames was investigated. Eleven full-scale cyclic and nine monotonic extended end-plate moment connection tests were conducted. Design procedures for determining the required bolt diameter and grade, end-plate thickness, and column flange thickness were developed. The proposed design procedure utilizes a strong column, strong connection, and weak beam design philosophy. This forces the connecting beam to provide the required inelastic deformations through formation of a plastic hinge adjacent to the connection region. The proposed design procedure was used to make comparisons with ninety experimental tests conducted over the past twenty-six years. A limited finite element study was conducted to investigate the behavior of the column flange. The experimental results demonstrate that extended end-plate moment connections can be detailed and designed to be suitable for use in seismic force resisting moment frames. The proposed design procedure strength predictions correlated well with the results from ninety experimental tests. The limited finite element modeling conducted as a part of this study, correlated well with the strength predictions produced by the proposed design procedure. / Ph. D.

An experimental investigation was conducted to study the inelastic rotation capability of flush end-plate moment connections. Seven specimens representing two-bolt and four-bolt flush end-plate configurations were tested under cyclic loading. "Quasi-static" or "slow-cyclic" loading histories suggested by SAC and the Applied Technology Council were used to load the specimens. Experimental results for maximum moment resisted by the connections were compared with analytical predictions. Moment strengths of the connections were calculated using yield-line theory to predict end-plate yielding and maximum bolt force calculations including prying action. Experimental results were also compared to previous research with regards to strength and stiffness. The inelastic rotation of connections was calculated and conclusions were drawn on the compliance of these connections with current AISC specifications. / Master of Science

This research has been aimed to introduce larger moment carrying connections for any type of buildings, in particular the metal building industry. A total of four connection configurations, namely eight-bolt extended four wide, eight-bolt extended stiffened, six bolt flush unstiffened and twelve bolt extended unstiffened, have been investigated. The last two configurations are proposed whereas the first two configurations have been tested before, but the design procedures need to be validated against the test results. Design procedures, namely yield line analysis and bolt force models, were proposed to calculate moment capacity for end-plate yielding, moment capacity at bolt rupture with prying action and moment capacity at bolt rupture without prying action. The calculated values from these procedures were compared with the values obtained from the experimental test data available (whether from the literature or from this testing program). The experimental data from already tested configurations, eight-bolt extended four wide and eight-bolt extended stiffened, was analyzed. It was concluded that for the eight-bolt extended four wide configuration, the experimental values matched with the calculated values. For the eight-bolt extended stiffened configuration reasonable match was found between the experimentally obtained data and theoretically calculated values only for shallower depths. Hence, it was concluded that two deeper tests need to be performed for this configuration. A full-scale testing program was conducted for ten specimens covering three configurations. The two new configurations (six bolt flush unstiffened and twelve bolt multiple row extended unstiffened) were designed for a shallow and deep beam depth and the behavior of each depth observed for a thin end-plate and a thick end-plate respectively (four tests for each configuration). Also, two deep beam tests, one each for thick and thin plate behavior, were done for the eight-bolt extended stiffened configuration. Based on the comparison, it was determined whether the predicted values were in reasonable agreement with the experimental values or not. The design procedures for both the new configurations appear to be validated for a range of design parameters. The calculated moment capacities for bolt rupture, based on the nominal material properties, were found to be safe when compared with the experimentally obtained moments. The calculations for end-plate yield moments was within ±10% of the experimental yield moment. Also, for the deep tests for eight-bolt extended stiffened the yield line analysis seems to be a valid model and the bolt force model appears to be safe in comparison to the experimental values. / Master of Science

An experimental investigation was conducted to study the extended end-plate moment connections subjected to cyclic loading. Seven specimens representing three end-plate moment connection configurations commonly used in the pre-engineered building industry were used. The connections were designed using yield-line theory to predict end-plate yielding and the modified Kennedy method to predict maximum bolt force calculations including prying action. A displacement controlled loading history was used to load the specimens. The maximum moments obtained experimentally and the experimental bolt forces throughout loading were compared with analytical predictions and finite element model results. The inelastic rotation of connections was calculated and conclusions were drawn on the compliance of these connections with current AISC specifications. / Master of Science

Este trabalho aborda ligações semi-rígidas com o objetivo de verificar a influência da flexibilidade na análise de estruturas metálicas, com o propósito de apresentar um modelo que represente o real comportamento das conexões assumindo uma situação intermediária entre totalmente rígida e totalmente flexível. Os procedimentos empregados para determinar as propriedades destas conexões estão embasados nos métodos descritos pelo anexo J do Eurocode 3 e recomendações do BCSA/SCI. Com intuito de automatizar o cálculo das conexões semi-rígidas foi implementado um programa computacional que fornece as propriedades necessárias das ligações entre vigas e pilares através da entrada de dados geométricos e especificações do material empregado. São abordadas ligações soldadas e ligações parafusadas com chapa de extremidade.O trabalho apresenta, ainda, uma avaliação da redistribuição de solicitações nas estruturas de aço. Fazendo a análise de um pórtico plano empregando molas rotacionais nos nós de encontro entre vigas e pilares inserindo a rigidez rotacional obtida através dos procedimentos numéricos apresentados neste trabalho. Esta mesma estrutura foi analisada da maneira tradicional, ou seja, considerando nós rígidos no encontro entre vigas e pilares. Através da analogia entre os resultados obtidos pelas duas análises é possível visualizar a diferença entre a distribuição nas solicitações. Dessa forma, é possível verificar a influência da rigidez das ligações na análise das estruturas metálicas. / This work approaches semi-rigid connections with the purpose to verify the influence of connections in the analysis of steel structures, with the intention to present a model that represents the real behavior of the connections assuming an intermediate situation between totally rigid and totally pinned. The used procedures to determine the properties of these connections are based in the described methods for the Annex J of the Eurocode 3 and BCSA/SCI. With intention to speed the calculations of the semi-rigid connections a computational program was implemented that supplies to the necessary properties of the connections between beams and columns through the geometric data entry and specifications of the employed material. They are boarded welded connections and connections bolted with extend end plate. The work presents, still, an evaluation of the new distribution of loads in the steel structures. Making the analysis of a plain frame using rotational springs between beams and columns inserting the gotten rotational rigidity through the presented numerical procedures in this work. This same structure was analyzed in the traditional way, that is, considering rigid we in the meeting between beams and columns. Through the analogy it enters the results gotten for the two analyses is possible to visualize the difference enters the distribution in the requests. Of this form, it is possible to verify the influence of flexibility in the analysis of the metallic structures.

Este trabalho aborda ligações semi-rígidas com o objetivo de verificar a influência da flexibilidade na análise de estruturas metálicas, com o propósito de apresentar um modelo que represente o real comportamento das conexões assumindo uma situação intermediária entre totalmente rígida e totalmente flexível. Os procedimentos empregados para determinar as propriedades destas conexões estão embasados nos métodos descritos pelo anexo J do Eurocode 3 e recomendações do BCSA/SCI. Com intuito de automatizar o cálculo das conexões semi-rígidas foi implementado um programa computacional que fornece as propriedades necessárias das ligações entre vigas e pilares através da entrada de dados geométricos e especificações do material empregado. São abordadas ligações soldadas e ligações parafusadas com chapa de extremidade.O trabalho apresenta, ainda, uma avaliação da redistribuição de solicitações nas estruturas de aço. Fazendo a análise de um pórtico plano empregando molas rotacionais nos nós de encontro entre vigas e pilares inserindo a rigidez rotacional obtida através dos procedimentos numéricos apresentados neste trabalho. Esta mesma estrutura foi analisada da maneira tradicional, ou seja, considerando nós rígidos no encontro entre vigas e pilares. Através da analogia entre os resultados obtidos pelas duas análises é possível visualizar a diferença entre a distribuição nas solicitações. Dessa forma, é possível verificar a influência da rigidez das ligações na análise das estruturas metálicas. / This work approaches semi-rigid connections with the purpose to verify the influence of connections in the analysis of steel structures, with the intention to present a model that represents the real behavior of the connections assuming an intermediate situation between totally rigid and totally pinned. The used procedures to determine the properties of these connections are based in the described methods for the Annex J of the Eurocode 3 and BCSA/SCI. With intention to speed the calculations of the semi-rigid connections a computational program was implemented that supplies to the necessary properties of the connections between beams and columns through the geometric data entry and specifications of the employed material. They are boarded welded connections and connections bolted with extend end plate. The work presents, still, an evaluation of the new distribution of loads in the steel structures. Making the analysis of a plain frame using rotational springs between beams and columns inserting the gotten rotational rigidity through the presented numerical procedures in this work. This same structure was analyzed in the traditional way, that is, considering rigid we in the meeting between beams and columns. Through the analogy it enters the results gotten for the two analyses is possible to visualize the difference enters the distribution in the requests. Of this form, it is possible to verify the influence of flexibility in the analysis of the metallic structures.

Este trabalho aborda ligações semi-rígidas com o objetivo de verificar a influência da flexibilidade na análise de estruturas metálicas, com o propósito de apresentar um modelo que represente o real comportamento das conexões assumindo uma situação intermediária entre totalmente rígida e totalmente flexível. Os procedimentos empregados para determinar as propriedades destas conexões estão embasados nos métodos descritos pelo anexo J do Eurocode 3 e recomendações do BCSA/SCI. Com intuito de automatizar o cálculo das conexões semi-rígidas foi implementado um programa computacional que fornece as propriedades necessárias das ligações entre vigas e pilares através da entrada de dados geométricos e especificações do material empregado. São abordadas ligações soldadas e ligações parafusadas com chapa de extremidade.O trabalho apresenta, ainda, uma avaliação da redistribuição de solicitações nas estruturas de aço. Fazendo a análise de um pórtico plano empregando molas rotacionais nos nós de encontro entre vigas e pilares inserindo a rigidez rotacional obtida através dos procedimentos numéricos apresentados neste trabalho. Esta mesma estrutura foi analisada da maneira tradicional, ou seja, considerando nós rígidos no encontro entre vigas e pilares. Através da analogia entre os resultados obtidos pelas duas análises é possível visualizar a diferença entre a distribuição nas solicitações. Dessa forma, é possível verificar a influência da rigidez das ligações na análise das estruturas metálicas. / This work approaches semi-rigid connections with the purpose to verify the influence of connections in the analysis of steel structures, with the intention to present a model that represents the real behavior of the connections assuming an intermediate situation between totally rigid and totally pinned. The used procedures to determine the properties of these connections are based in the described methods for the Annex J of the Eurocode 3 and BCSA/SCI. With intention to speed the calculations of the semi-rigid connections a computational program was implemented that supplies to the necessary properties of the connections between beams and columns through the geometric data entry and specifications of the employed material. They are boarded welded connections and connections bolted with extend end plate. The work presents, still, an evaluation of the new distribution of loads in the steel structures. Making the analysis of a plain frame using rotational springs between beams and columns inserting the gotten rotational rigidity through the presented numerical procedures in this work. This same structure was analyzed in the traditional way, that is, considering rigid we in the meeting between beams and columns. Through the analogy it enters the results gotten for the two analyses is possible to visualize the difference enters the distribution in the requests. Of this form, it is possible to verify the influence of flexibility in the analysis of the metallic structures.

Repair of peripheral nerve injury often results in poor functional motor recovery. This deficit has previously been attributed to the failure of axons to regenerate into the muscle. However, we have recently reported that following nerve injury in mice, axons have regenerated to the motor end plate in animals with poor recovery. We proposed that following axonal injury, there is a critical period during which the axon must reach the muscle in order to form a functional neuromuscular junction. We have developed a mouse model of prolonged denervation, in which the sciatic nerve is crushed repeatedly every few days, preventing regenerating axons from reaching the muscle. This multiple crush model allows us to vary the period of denervation by modifying the number of crushes. Motor recovery as assessed using the toe-spreading score occurs after 3 or 4 multiple crushes every 7 days (24 or 31 days of denervation) but not after 5 crushes (38 days). Immunostaining for alpha-bungarotoxin and neurofilament confirmed end plate reinnervation. Thus following denervation > 38 days, a motor deficit persists despite end plate reinnervation. Although the mechanism for the deficit requires investigation, these results suggest that functional neuromuscular junction reestablishment more than end plate reinnervation and that there is a time limit for functional synapse reformation.

No description available.