Application of the ADAMS program to deployable space truss structures

The need for a computer program to perform kinematic and dynamic analyses of large truss structures while deploying from a packaged configuration in space led to the evaluation of several existing programs. ADAMS (automatic dynamic analysis of mechanical systems), a generalized program from performing the dynamic simulation of mechanical systems undergoing large displacements, is applied to two concepts of deployable space antenna units. One concept is a one cube folding unit of Martin Marietta's Box Truss Antenna and the other is a tetrahedral truss unit of a Tetrahedral Truss Antenna. Adequate evaluation of dynamic forces during member latch-up into the deployed configuration is not yet available from the present version of ADAMS since it is limited to the assembly of rigid bodies. Included is a method for estimating the maximum bending stress in a surface member at latch-up. Results include member displacement and velocity responses during extension and an example of member bending stresses at latch-up

Service-Learning in One State: Results of the North Carolina Service-Learning Inventory

Recent years have seen greatly expanded interest in service-learning among educators at both the K-12 and college levels. By most accounts, the initiation of service-learning programs and courses has come about in response to a recognized need to provide more effective citizenship education and to do a better job of preparing young people to be active members of their communities (see, for example, Barber). What is less clear, however, is the overall shape and substance of these programs. Because service-learning usually has a strong local component, not very much is known of the broader patterns and trends at the national and state levels