No description available.

The elasto-dynamics of flexible frame structures is of interest in many areas of engineering. In certain structural systems the deflections can be large enough to warrant a nonlinear analysis. For example, offshore structures, long suspension bridges and other relatively slender structures used in space applications require a geometrically nonlinear analysis. In addition, if the structure has deployable elements, as in some space structures, the required analysis becomes even more complex. Typical examples are spacecraft antennae, radio telescopes, solar panels and space-based manipulators with deployable elements. The main objective of the present work is to formulate the problem of sliding beams undergoing large rotations and small strains. Further we aim to develop efficient finite element technique for analysis of such complex systems. Finally we wish to examine the nature of the motion of sliding beams and point out its salient features. We start with two well known approaches in the nonlinear finite element static analysis of highly flexible structures, namely, the updated Lagrangian and the consistent co-rotational methods and extend these techniques to dynamic analysis of geometrically nonlinear beam structures. We analyse several examples by the same methods and compare the performance of each for efficiency and accuracy. Next, using McIver's extension of Hamilton's principle, we formulate the problem of geometrically flexible sliding beams by two different approaches. In the first the beam slides through a fixed rigid channel with a prescribed sliding motion. In this formulation which we refer to as the sliding beam formulation, the material points on the beam slide relative to a fixed channel. In the second formulation the material points on the fixed beam are observed by a moving observer on a sliding channel and the beam is axially at rest. The governing equations of motion for the two formulations describe the same physical problem and by mapping both to a fixed domain, using proper transformations, we show that the two sets of governing equations become identical. It is not, possible to find analytical solutions to our problem and we choose the Galerkin numerical method to obtain the transient response of the problem for the special case axially rigid beam. Next we follow a more elegant approach wherein we use the developed incremental nonlinear finite element approaches (the updated Lagrangian and the consistent co-rotational method) in conjunction with a variable time domain beam finite elements (where the number of elements is fixed and as mass enters the domain of interest, but the sizes of elements change in a prescribed manner in the undeformed configuration). To verify the formulation and its computational implementation we analyse many examples and compare our findings with those reported in the literature when possible. We also use these illustrative examples to identify the importance of various terms such as axial flexibility and foreshortening effects. Finally we look into the problem of parametric resonance for the beam with periodically varying length and we show that the regions of stability obtained in the literature, using a linear analysis, do not hold when a more realistic nonlinear analysis is undertaken. / Graduate

No description available.

No description available.

No description available.

Individuals with autism spectrum disorder (ASD) demonstrate deficits in social behavior which may hinder them from engaging in social interactions. Results of descriptive analyses suggest that children who engage in prosocial behaviors, such as sharing, likely receive social positive reinforcement from peers in the form of attention. However, functional relations between prosocial behaviors, such as sharing, and their maintaining consequences have yet to be identified. Thus, the purpose of this study was to extend previous research by evaluating the naturally maintaining contingencies associated with sharing in three preschool-aged children with ASD. Functional analyses have traditionally been used to identify the function of maladaptive behavior; however, we extended the same methodological approach to identify functional relations of sharing. Results suggest that sharing was maintained by attention for two participants and was multiply-maintained by both attention and access to tangibles for one participant. These findings indicate that the functional analysis methodology is appropriate to understanding prosocial behaviors. In addition, results advance our understanding of prosocial behavior and may better inform methods of how to functionally teach sharing to individuals with ASD.

No description available.

A critical step in addressing problem behavior is identifying the function of problem behavior, or reason for engaging in the problem behavior, using functional analysis (FA). Individuals with CHARGE Syndrome engage in problem behaviors that vary across topographies and etiology (e.g., pain, anxiety, sensory concerns; Hartshorne et al., 2017). The literature has illustrated time and time again the effectiveness of these procedures across populations, settings, age groups, and topographies of behavior; however, no studies have been documented exploring the utility of FA procedures with individuals with CHARGE Syndrome. The current study completed brief functional analyses (Northup et al., 1991) with individuals diagnosed with CHARGE Syndrome who presented with problem behavior. Participants included individuals between the ages of 8 to 22 years old diagnosed with CHARGE Syndrome and presenting with problem behaviors. Results indicated that BFA procedures were successful in identifying the function of problem behavior with 4 out of 5 participants.

No description available.

No description available.