Failure Prediction of Anisotropic Material
Basic mathematical elements of a higher order failure theory for anisotropic material are outlined. Surface closure is ensured by requiring a tensor polynomial to satisfy constraint conditions....
Microcrack Interaction Toughening in Ceramics and CMCs
The generation of microcracks, which causes an extension of the damage zone at values of stress intensity factor, K, below the expected critical level represented by KIC...
An Elasticity Solution for a Transversely Isotropic Material Containing a Spherical Shell Under Arbitrary Axisymmetric Loading
A three-dimensional elasticity solution is obtained for a transversely isotropic solid containing an isotropic spherical membrane shell. Perfect bonding is assumed between the shell and...
Granular Flow on a Bumpy Inclined Chute
Theoretical predictions for steady, uniform granular flows of identical, smooth, nearly elastic disks and spheres on bumpy inclined chutes are obtained. Kinetic constitutive theory is...
Pattern Formation and Time-Dependence in Flowing Sand
The authors present results for a number of experiments on flowing granular materials and a novel cellular automata model for the flow of these materials when the grains are long and thin....
Modeling the Chaotic Behavior in Simple Shear Granular Flows
Simple shear granular flows have demonstrated a variety of puzzling phenomena. Both computer simulations and physical experiments have discovered particle grouping, layering and shear...
Mechanics of Granular Materials at Very Low Effective Stress Levels
Gravity's influence on laboratory specimens of uncemented granular materials subjected to low effective stresses, makes it impossible to evaluate constitutive properties in an unambiguous...
Thermal Load for p-Version Laminated Elements
A p-version finite element formulation is presented for determining temperature stresses in laminated composite axisymmetric problems. Formulation for a rectangular axisymmetric p-version...
Numerical and Experimental Studies of Vibration of Impact Damaged SMC Composite Plates
This paper presents a parametric finite element study and an experimental investigation to free vibration of clamped, circular short-fiber reinforced composite plates with various degrees...
Stresses in Open Section Fiber Reinforced Composite Beams Under Constant Shear Loading
A strength of materials approach from the ply level is used to derive expressions for stresses in statically determinate open section composite beams subjected to constant shear loading....
Macromodeling of Complex Composites
Dimensionally reduced p-version finite elements based on higher order theory are developed for modeling laminated composite plates and shells in the presence of cracks, notches, and delaminations....
Laboratory Testing of Mechanical Rock Bolts
An analytical solution to a boundary value problem of a clamped cylindrical panel with anti-symmetric angle-ply laminations subjected to transverse loads is presented. Sanders' kinematic...
Design Concepts for a Lunar Concrete Production Facility
This paper discusses concrete production fundamentals on the earth and identifies applicable features required for lunar concrete production. Production principles unique to the lunar...
An Analysis of an Inflatable Module for Planetary Surfaces
Design and construction of a structure on planetary surfaces requires addressing a host of issues not encountered on Earth. A modular quilted inflatable structure consisting of thin membranes...
Prototype Lunar Base Construction Using Indigenous Materials
A lunar base must be designed to withstand harsh lunar conditions, which include severe internal pressure loads and a high radiation level. Yet to provide for economical and rapid future...
Cylindrical Fabric-Confined Soil Structures
Using the local soil as a structural material can greatly reduce the transport requirements for constructing Lunar and Martian surface structures. A fabric-soil structural concept which...
Lunar Habitats?Places for People
As part of President George Bush's Space Exploration Initiative, lunar bases or habitats are envisioned for long-term habitation by humans. This paper presents factors that should be considered...
Experimental, Physical and Numerical Modeling of Lunar Regolith and Lunar Regolith Structures
An extensive series of laboratory strength and deformation experiments have been performed on a lunar regloith simulant. Results of these experiments are compared to results from experiments...
The Design of a Permanent Lunar Research Station
The advancement of the United States efforts in space exploration and research requires the establishment of a permanent manned lunar research station. This paper explores the possible...
Lunar Base Requirements for Human Habitability
This paper presents some of the requirements for lunar surface habitation. Emphasis is placed on human factor and environment-behavior requirements that impact on habitability for medium-duration...
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