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

Stiffeners are used as a means of providing additional support to columns at beam connection locations. They are added when the strength of the column is exceeded but full moment strength of the beam section is desired. In determining the design of column stiffeners, there are no specifications for determining the distribution of load between the column web and stiffeners. The AISC Load and Resistance Factor Design Specifications provides guidelines for determining the stiffener area but no specifications are given. The actual loads taken by the stiffener and web are therefore not truly known. In this study, experiments were done to determine the load supported by the stiffeners and web when tensile forces are applied to the specimen. The initial stiffener design for the test specimens was based on LRFD guidelines. The actual load distribution between the column web and stiffeners is determined from strain data obtained during testing. This distribution is compared with the assumed loads obtained from the initial LRFD calculations. Finite element analysis is also utilized to confirm the consistency of the results obtained from the experiments. Using this information, a new method is developed which better predicts the distribution of load between the column web and the stiffener. / Master of Science

<p> A research programme is presented for the analytical. evaluation of the deflections of Vierendeel trusses comprised of semi-rigid connections under panel feint loadings. The semi-rigid connections are made of two unequal width square ESS members welded at right angles. As the flexibility of the joints increases when the width ratio is less than 1.0, the joints are unable to develop the moment capacity of the web member and excessive deflections limit functional capability of the truss. Hence, several types of joint reinforcement are recommended. A yield line method is attempted to estimate the strength capacity of the joint with and without reinforcements. In addition, a plate analysis forms the basis for estimating elastic joint stiffness for evaluating anticipated deflections at mid span. </p> / Thesis / Master of Engineering (MEngr)

No description available.

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

No description available.

No description available.

No description available.

Three end-plate moment connection configurations are prequalified for special moment frames for seismic applications in AISC 358-10. The eight bolt extended stiffened connection is the strongest of the three configurations, but it can only develop approximately 30 percent of currently available hot-rolled beam sections. The strength of this configuration is limited by bolt strength. There is a need for a stronger end-plate moment connection, hence the reason for the development and validation of a twelve bolt configuration. Equations were developed for the design procedure using various analytical methods, which included yield line analysis and an effective tee stub model. An experimental program was conducted, which consisted of the full-scale cyclic testing of four end-plate moment connections. The intention of the testing was to develop and validate the design procedure, and prequalify a new twelve bolt configuration. A displacement-controlled loading protocol was applied according to AISC 341-10. The experimental results showed that the model for thick end-plate behavior is conservative by 6.7%, the model for end-plate yielding is conservative by 8.8%, and the model for bolt tension rupture with prying conservatively predicts by 18.5%. The specimens that were designed to form a plastic hinge in the beam fractured in a brittle manner. The deep beam specimen fractured in the first 2% story drift cycle, and the shallow beam specimen fractured in the second 3% story drift cycle. The fracture of the prequalification specimens was determined to have been caused by stiffeners of high yield stress relative to the beam yield stress. / Master of Science / End-plate moment connections are a common way to create a rigid joint between beams and columns. Before using a moment connection in a steel building to resist horizontal earthquake loads, each connection configuration must be tested at full-scale and meet performance criteria prescribed in the applicable building code (in this case, the Seismic Provisions for Structural Steel Buildings published by the American Institute of Steel Construction). Three end-plate moment connection configurations have been previously “prequalified” for high seismic regions, which means that sufficient previous testing has shown adequate performance. The eight bolt end-plate moment connection is the strongest of the three configurations, but it can only develop approximately 30 percent of currently available hot-rolled steel beam sections. The strength of this configuration is limited by bolt strength. There is a need for stronger end-plate moment connections, which motivated the development and validation of a twelve bolt configuration in this thesis. Equations were developed for the design of the twelve-bolt end-plate moment connection including equations to predict when the bolts would fracture and when the end-plate would yield. An experimental program was conducted, which consisted of the full-scale cyclic testing of four end-plate moment connections. The intention of the testing was to validate the design procedure and demonstrate that the connection could withstand significant inelastic rotation. The connection assembly was cycled back and forth according to a displacement protocol prescribed in the Seismic Provisions for Steel Buildings. The experimental results showed that the equations were able to predict bolt rupture within 6.7% of the applied moment at fracture, the equation for end-plate yielding was conservative by 8.8%, and the equation for bolt fracture with prying action was conservative by 18.5%. The specimens that were intended to show the connection could withstand significant inelasticity fractured in an unexpected brittle manner. The deep beam iv specimen fractured in the first 2% story drift cycle, and the shallow beam specimen fractured in the second 3% story drift cycle, neither of which reach the target of 4% story drift. The fractures were determined to have been caused by stiffeners that had too high a yield stress relative to the beam yield stress.