Recent advances in structural technology for large deployable and erectable spacecraft

Ultra-low mass deployable and erectable truss structure designs for spacecraft are identified using computerized structural sizing techniques. Extremely slender strut proportions are shown to characterize minimum mass spacecraft which are designed for shuttle transport to orbit. Discrete element effects using a recently developed buckling theory for periodic lattice type structures are presented. An analysis of fabrication imperfection effects on the surface accuracy of four different antenna reflector structures is summarized. The tetrahedral truss has the greatest potential of the structures examined for application to accurate or large reflectors. A deployable module which can be efficiently transported is identified and shown to have significant potential for application to future antenna requirements. Investigations of erectable structure assembly are reviewed

Supersonic flutter of a thermally stressed flat panel with uniform edge loads

Supersonic flutter of thermally stressed flat panel with uniform edge load

Market Day

Fiction by David Hear

Vibration and Instability of Plate-Assemblies including Shear and Anisotropy (VIPASA) user's guide, addendum

Extensions developed at Langley Research Center to the VIPASA computer program are described including a procedure for simple thermal stress analysis and options for graphical display of output. Input requirements for operation of the modified program are given in detail

The effect of ring distortions on buckling of blunt conical shells

A rigorous analytical study of cones stiffened by many thin-gage, open-section rings is presented. The results are compared with data previously obtained from uniform pressure tests of the Viking mission flight aeroshell and of the Viking structural prototype aeroshells. A conventional analysis, in which the rings are modeled as discrete rigid cross sections, is shown to lead to large, unconservative strength predictions. A more sophisticated technique of modeling the rings as shell branches leads to much more realistic strength predictions and more accurately predicts the failure modes. It is also shown that if a small initial imperfection proportional to the shape of the buckling mode is assumed, the critical buckling modes from analysis and test are in agreement. However, the reduction in buckling strength from the perfect-shell predictions is small

Review: Fiddler Crabs of the World by Jocelyn Crane

Review of Jocelyn Crane, Fiddler Crabs of the World. Ocypodidae: Genus Uca. XXIV+ 737 pp., 369 photographs, 101 figures, 21 maps. ISBN 08102-6, Princeton University Press, Princeton, New Jersey, 1975. $75.00

Calliax jonesi, N. Sp. (Decapoda: Thalassinidea: Callianassidae) from the Northwestern Bahamas

Two specimens of Calliax jonesi, n. sp., were collected from fine carbonate sediments in 3 to 5 m of water at Bimini Harbor, Bahamas. Of the species presently assigned to the genus Calliax de Saint Laurent, 1973, C. jonesi appears to be most closely related to C. quadracuta (Biffar, 1970), presently known from the Atlantic coast of Venezuela and the Florida Keys. Calliax jonesi is distinguished from C. quadracuta by: (1) the absence of a distal spinose process on the dorsal and ventral margins of the carpus of the first pair of chelipeds, (2) the armature and shape of uropods and telson, and (3) the shape of male first pleopod. Calliax jonesi, C. quadracuta, and at least two undescribed species from the northwestern Atlantic appear to form a closely related species complex which may not be congeneric with the type species, C. lobata (de Gaillande & Lagardère, 1966), and other species assigned to Calliax

Filing Requirements under the Montana Uniform Commercial Code

Filing Requirements Under the Montana Uniform Commercial Cod

Computer program for structural analysis of layered orthotropic ring-stiffened shells of revolution (SALORS): Linear stress analysis option

Program handles segmented, laminar, orthotropic shells with discrete rings. Meridional variations are handled in material properties, temperatures, and wall thickness. Allows for linear variations of temperature through each layer of shell wall

Structural sizing considerations for large space structures

A number of missions for the space shuttle were proposed which involve placing large truss platforms on-orbit. These platforms range in size from tens of meters in span for reflector application to several thousand meters for solar power collector application. These proposed sizes and the operational requirements considered are unconventional in comparison to Earthbound structures and little information exists concerning efficient proportions of the structural elements forming the framework of the platforms. Such proportions are of major concern because they have a strong influence on the packaging efficiency and, thus, the transportation effectiveness of the shuttle. The present study is undertaken to: (1) identify efficient ranges of application of deployable and erectable platforms configured for shuttle transport to orbit, and (2) determine sensitivity to key parameters of minimum mass deployable and erectable platform designs