Bridge and gantry cranes are crucially important elements in the industrial complex; they are used in many areas such as shipping, building construction, steel mills, and nuclear facilities, just to name a few. These types of systems tend to be highly flexible in nature, generally responding to commanded motion with oscillations of the payload and hook. The response of these systems to external disturbances, such as wind, is also oscillatory in nature. Often, the oscillations of the hook and payload have undesirable consequences. For instance, precise manipulation of payloads is difficult when cable sway is present. Oscillation of the hook can also present a safety hazard. For these reasons, the ability to successfully negate these detrimental dynamics can result in improved positioning, quicker settling time, and improved safety. This thesis addresses the dynamic properties of bridge and gantry cranes in an effort to develop a control scheme that enables strides to be made in these areas of positioning, efficiency, and safety. The fundamental advancement arising from this thesis is the development of a control scheme that enables precise positioning of the payload while motion and disturbance-induced oscillations are eliminated. A command generation technique uniquely suited for reducing oscillation in low-frequency flexible systems is examined and utilized in the control. The control scheme is implemented on a 10-ton bridge crane for validation purposes.

This thesis examines the pre-design documentation from the renovation of three historic theaters located in Detroit, Michigan. Two theaters hired architectural firms to produce a pre-design document. The third theater utilized a design-build approach to renovation. Interviews were conducted to review the approach and final outcomes. It became evident through the analysis of the documentation and interviews that it was beneficial in the renovation of a historic theater to have a comprehensive predesign process that identifies: the nature of the pre-design document, the nature of the client, the nature of the pre-design team, and the scope of work and time available. It also became apparent that the organizational approach that would apply to most any document for a heritage building should follow the Problem Seeking format of: Form, Function, Time and Economy. Utilizing this format for a pre-design record should yield a document that is concise, comprehensive and flexible.

The seismic behavior of port container cranes has been largely ignored-by owners, operators, engineers, and code officials alike. This is despite their importance to daily port operations, where historical evidence suggests that port operational downtime following a seismic event can have a crippling effect on the affected local, regional, and national economies. Because the replacement time in the event of crane collapse can be a year or more, crane collapse has the potential to be the "critical path" for post-disaster port recovery. Since the 1960's, crane designers allowed and encouraged an uplift response from container cranes, assuming that this uplift would provide a "safety valve" for seismic loading; i.e. the structural response at the onset of uplift was assumed to be the maximum structural response. However, cranes have grown much larger and more stable such that the port industry is now beginning to question the seismic performance of their modern jumbo container cranes. This research takes a step back, and reconsiders the effect that uplift response has on the seismic demand of portal-frame structures such as container cranes. A theoretical estimation is derived which accounts for the uplift behavior, and finds that the "safety valve" design assumption can be unconservative. The resulting portal uplift theory is verified with complex finite element models and experimental shake-table testing of a scaled example container crane. Using the verified models, fragility curves and downtime estimates are developed which characterize the risk of crane damage and operational downtime for three representative container cranes subjected to a range of earthquakes. This research demonstrates that container cranes designed using previous and current standards can significantly contribute to port seismic vulnerability. Lastly, performance-based design recommendations are provided which encourage the comparison of demand and capacity in terms of the critical portal deformation, using the derived portal uplift theory to estimate seismic deformation demand.

Serving as critical gateways for international trade, seaports are pivotal elements in transportation networks. Any disruption in the activities of port infrastructures may lead to significant losses from secondary economic effects, and can hamper the response and recovery efforts following a natural disaster. Particularly poignant examples which revealed the significance of port operations were the 1995 Kobe earthquake and 2010 Haiti earthquake in which liquefaction and lateral spreading of embankments imposed severe damage to both structural and non-structural components of ports. Since container wharf structures are responsible for loading and unloading of cargo, it is essential to understand the performance of these structures during earthquakes. Although previous studies have provided insight into some aspects of the seismic response of wharves, limitations in the modeling of wharf structures and the surrounding soil media have constrained the understanding of various features of the wharf response. This research provides new insights into the seismic behavior of wharves by using new and advanced structure and soil modeling procedures to carry out two and three-dimensional seismic analyses of a pile-supported marginal wharf structure in liquefiable soils. Furthermore, this research investigates the interaction between cranes and wharves and closely assesses the role of wharf-crane interaction on the response of each of these systems. For this purpose, the specific effect of wharf-crane interaction is studied by incorporating advanced models of the crane with sliding/uplift base conditions. To reduce the computational time required for three-dimensional nonlinear dynamic analysis of the wharf in order to be applicable for probabilistic seismic demand analysis, a simplified wharf model and an analysis technique are introduced and verified. In the next step probabilistic seismic demand models (PSDMs) are generated by imposing the wharf models to a suit of ground deformations of the soil embankment and pore water pressure generated for this study through free-field analysis. Convolving PSDMs and the limit states, a set of fragility curves are developed for critical wharf components whose damage induces a disruption in the normal operation of ports. The developed fragility curves provide decision makers with essential tools for maximizing investment in wharf retrofit and fill a major gap in seismic risk assessment of seaports which can be used to assess the regional impact of the damage to wharves during a natural hazard event.

Welding is one of the most applied technics in the world for joining steel. Welds are liable to the phenomenon of fatigue, which is, primarily, the formation of a crack and consequently reduction of strength due to the action of time varying loads. Fatigue is one of the main causes of failure in steel structures. The aim of this thesis is to do static and dynamic analyses of a forestry crane with the purpose of using the analyses to determine the lifetime due to fatigue of welded components. Two methods for fatigue assessment are used in this work, the Hot-Spot Method and the Notch Stress Method. The first boom, which is a key component for the crane, is analyzed in a Finite Element Method (FEM) software. The found principal stress in accordance with the notch stress method in the first boom is ±165 MPa for the analyzed load case, rendering in a stress range of 330 MPa. The fatigue strength class FAT-225 (m=3), leads to an expected number of 633000 cycles, with a probability of survival of 97,7% for this case. / Svetsning är en av de vanligaste teknikerna för sammanfogning av stål. Svetsar är känsliga för utmattning. Utmattningsfenomenet består primärt av en initial dislokation som genom tidsvarierande belastning formar en spricka som växer och därmed reducerar styrkan i konstruktionen. Utmattning är en av de vanligaste orsakerna till skador i stålkonstruktioner. Målet med detta arbete är att genomföra både statiska och dynamiska analyser av en skogsmaskins kran i avseende att bestämma utmattningslivslängden för dess svetsade konstruktioner. Två metoder för utvärdering används i detta arbete, hot-spot-metoden och notch-stress-metoden. Kranens första bom (lyftarmen) som är en huvudkomponent i kranen analyseras med hjälp av ett Finita Element program i enlighet med notch-metoden. Högsta funna spänningsvariationen i första huvudspänningsriktningen var ±165 MPa för ett av de analyserade lastfallen. Utmattningsklass FAT 225 (m=3) ger en uppskattning om utmattningslivslängd på 633000 cykler med en sannolikhet för överlevnad på 97.7% i detta fall.

Not available / text

This project asserts that male Naturalist authors were not “hypermasculine” acolytes of strident manhood, but instead offer alternative constructions which they portray as less traumatic and more cohesive than prevailing social notions of normative male behavior. I maintain that the rise of the concept of manhood advocated by Theodore Roosevelt in the early decades of the twentieth century contributed to this misconception, for it generated a discourse of “manly” individualism which became equated with socially acceptable performances of masculinity for many Americans. My first chapter illustrates the gradual evolution of an individualistic, violent, and strident concept of manhood, which I label “strenuous masculinity,” through the rhetoric of Theodore Roosevelt. The second chapter explores the ways in which Stephen Crane’s fiction illuminates the trauma and confusion inherent in strenuous concepts of manhood. Many of Crane’s stories, like “Five White Mice,” demonstrate the failure of individualism, while others, like “The Open Boat,” document a more positive construction of what I call “homosocial manhood.” In my third and final chapter, I attempt to prove that Richard Wright’s early texts showcase a range of possible outcomes of black male attempts to stand up to racial oppression. I document that Uncle Tom’s Children and Native Son both depict a continuum of confrontation, with individual violence on one end of the spectrum and non-violent group protest on the other. Furthermore, because individual resistance is consistently equated with the suffering and death of the protagonists, my project implies that strenuous manhood also fails to provide a site for effectual and sustainable opposition to the negating forces of racial oppression. / Theodore Roosevelt and the transformation of American masculinity -- "The youth leaned heavily on his friend" : alternative constructions of masculinity in Stephen Crane's fiction -- Richard Wright's early fiction as a rejection of the racial oppression of strenuous manhood. / Department of English

Millions of cranes are used around the world. Because of their wide-spread use in construction industries, boom cranes are an important class of cranes whose performance should be optimized. One limitation of most boom cranes is they are usually attached to a stationary base or a mobile base that is only used for initial positioning and not during operation. This limits the workspace of the boom crane significantly. If a boom crane was attached to a mobile base that could be safely used during lifting operations, then the boom crane workspace could be extended significantly. The problem with using cranes, and in particular mobile cranes, is the large oscillations of the payload that are typically induced when moving the crane. One control strategy that has been used to control oscillation on other types of cranes is called Input Shaping, a command filtering technique that reduces motion-induced vibration in oscillatory systems. This thesis develops a dynamics model for a mobile boom crane and analyzes the difficulty of controlling payload oscillation on a boom crane. Input shaping will shown to be effective for controlling oscillation on boom cranes. A new method for operating a boom crane in Cartesian coordinates will also be shown. This thesis will also detail the design of a small-scale mobile boom crane for experimental and research purposes. A substantial part of this thesis will also focus on the development of new input-shaping methods for nonlinear drive systems commonly found on boom and other types of cranes. An example application of a control system featuring input shaping for an industrial bridge crane will also be discussed.

The rapid movement of machines is a challenging control problem because it often results in high levels of vibration. As a result, flexible machines are typically moved relatively slowly to avoid such vibration. Therefore, motion-induced vibration limits the operational speed of the system. Input shaping is one method that eliminates motion-induced vibrations by intelligently designing the reference command such that system vibration is cancelled. It has been successfully implemented on a number of systems, including bridge and tower cranes. The implementation of input shaping on cranes provides a substantial increase in the operational efficiency. Unfortunately, most cranes, once erected, have limited or no base mobility. This limits their workspace. The addition of base mobility could help extend the operational effectiveness of cranes and may also expand crane functionality. Mobile cranes may also be better suited for use in harsh and/or distant environments. Teleoperation of oscillatory systems, such as cranes, then becomes another avenue for advancement of crane functionality. Base mobility in cranes presents both additional control challenges and operational opportunities. A crane with base mobility is redundantly actuated (overactuated), such that multiple combinations of actuators can be used to move a payload from one location to another. This opens the possibility for the selection of a combination of actuation that provides both rapid motion and limited system vibration. The extension of input shaping into this operational domain will provide a method to maximize effective actuation combinations. Toward addressing these issues, new multi-input shaping methods were developed and applied to a mobile, portable tower crane. During this development, a firm understanding of robust input shaping techniques and the compromises inherent to input shaper design was formed. In addition, input shaping was compared to other command generation techniques, namely lowpass and notch filtering, and proven to be superior for vibration reduction in mechanical systems. Another, new class of input shapers was also introduced that limit the input shaper induced overshoot in human operated systems. Finally, a series of crane operator studies investigated the application of input shaping techniques to teleoperated cranes. These studies suggested that input shaping is able to dramatically improve remote crane operator performance.

Recent decades have been witness to explosive leaps in manufacturing productivity. Advances in communication technology, computing speed, control theory, and sensing technology have been significant contributors toward the increased productivity and efficiency that industry has exhibited. The continued growth of technological equipment and engineering knowledge challenges engineers to fully utilize these advancements in more sophisticated and useful automation systems. One such application involves enhancing bridge and gantry crane operation. These systems are used throughout the globe, and are critical aspects of industrial productivity. Consequently, improving the operational effectiveness of cranes can be extremely valuable. Effective control of cranes can be largely attributed to two distinct, but related aspects crane manipulation: 1) the expertise of operators, which are responsible for issuing commands to the structures, and 2) the dynamic properties of cranes, which influence how the structures respond to issued commands. Accordingly, the operational efficiency of cranes can be influenced by changing both the way that operators issue commands to cranes, and also how the crane responds to issued commands. This thesis is concerned with dynamic control theory of flexible machines, and human/machine interaction, especially as these areas relate to industrial crane control. In the area of dynamic control, this thesis investigates control strategies that are specifically suited for use on systems that possess common actuator nonlinearities, like saturation, rate limiting, dead-zone, backlash, and finite-state actuation. In the area of human/machine interaction, this thesis investigates the effects of different crane interface devices on the operational efficiency of cranes.