SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Experimental investigation to determine stability, surface deformation characteristics, and extent of plastic yielding associated with surface cracks in plates subjected to tensile loading
Notched metal crack initiation, determining high cyclic loads effects by prior local plastic behavior at stress concentration
Impulsively loaded rigid plastic continua deformation lower bounds calculation, considering beams and plates
Sounding rockets motors with integrally molded plastic case and nozzle, discussing cost effectiveness and demonstration tests
Stress analysis of thin elastoplastic shells with large displacements loaded into strain hardening range, assuming plastic strain incompressibility
Electron, proton and UV irradiation effects on CdS solar cell protective plastic films with or without adhesive coatings, measuring transmission changes
Plastic track detectors calibration for heavy charged particles in cosmic ray experiments, considering track etching rates as function of particle charge and velocity
Thin spherical roller supported domes stability and axisymmetric deformation under apex point loads, investigating plastic buckling and inelastic strain effects
Etchant type, concentration and temperature effect on various plastics track etching ratio and sensitivity
Heavy cosmic ray nuclei track counts in plastics, examining Apollo mission 8 and 12 helmets
Three dimensional elastic plastic solid, calculating stress and deformation with finite difference procedure
Large plastic strains in fiber in sheet bending for wide angle range, using Hill theory
Two phase fiber reinforced composites under polyaxial stresses, predicting plastic behavior by deformation theory
Axisymmetric plastic deformation of imperfection sensitive spherical shell after elastic buckling, considering load carrying capacity
Commercially available plastic film materials that remain flexible at cryogenic temperatures and resist failures caused by folds and wrinkles created during expulsion were investigated for use in expulsion bladders for liquefied gases. Compatible adhesive systems, fabrication techniques, and results of impact and dynamic loading tests are summarized.
Method is described for interplying resin absorbing, glass bleeder cloth with the layup for fabricating laminated nonflammable plastic structures with wrinkle-free surfaces.
Thermal contact conductance test data at high vacuum were obtained from two Armco iron specimens having smooth, large radii of curvature, convex, one-half wave length surfaces. The data are compared with calculations based on two macroscopic elastic deformation theories and an empirical expression. Major disagreement with the theories and fair agreement with the empirical expression resulted. Plastic deformation of all the contacting surfaces was verified from surface analyzer statistics. These results indicate that the theoretical assumption of macroscopic elastic deformation is inadequate for accurate prediction of heat transfer with light loads for Armco iron specimens similar to those used in this investigation.
On Apollo missions, the individual astronauts' high Z particle exposure is measured by means of Lexan polycarbonate plastic. These layers form one component of the passive dosimetry packets worn in the constant wear garment. They serve as threshold type, high Z, charged particle track detectors, recording only the very highly ionizing particles. The detectors yield information on the particles' charge, energy, and direction of travel. This data, in turn, is used to obtain the track fluence, the stopping particle density as an integral Z distribution, and the particles' integral LET spectrum. Some of the data gathered on Apollo missions 8-13 is presented.