Scientific and Technical Aerospace Reports Volume 39 April 6, 2001

20010024162 Army Research Lab., Adelphi, MD USA
Energy Balance Model for Imagery and Electromagnetic Propagation
Rachele, Henry, Army Research Lab., USA; Tunick, Arnold, Army Research Lab., USA; Journal of Applied Meteorology; September
2000; Volume 33, No. 8, pp. 964-976; In English
Report No.(s): AD-A385345; ARL-RP-5; Copyright; Avail: Defense Technical Information Center (DTIC)
The character of temperature and moisture gradients in the atmospheric surface layer is shown to be related to the intensity
of visual distortions or ”blurring” of images routinely detected by electro-optical systems and sensors.
DTIC
Energy Budgets; Atmospheric Energy Sources; Temperature Gradients; Moisture
20010025823 NASA Marshall Space Flight Center, Huntsville, AL USA
Modeling of Fillets in Thin-Walled Structures for Dynamic Analysis
Seugling, Richard M., North Carolina Univ., USA; Brown, Andrew M., NASA Marshall Space Flight Center, USA; [2001]; 1p;
In English; 19th; Modal Analysis, 5-8 Feb. 2001, Kissimmee, FL, USA; No Copyright; Avail: Issuing Activity; Abstract Only
Relatively new developments in manufacturing methods have made it possible to produce machined parts with a wall thickness
of less than 0.010”. While the parts are being machined. Fillets of relatively large radius to thickness ratios are created by
the milling tool. This paper discusses an accurate new technique for finite-element modeling of fillets for dynamic and stiffness
analysis using efficient plate elements rather than more computationally intensive, high density solid meshes, A simple filleted
cantilever beam of 0.040” thickness, 1.6” length, 1” depth, and 0.250” radius in the corner was modeled using both solid elements
and several different plate element geometries. The finite element results were then compared with static and modal testing of
a machined sample. The highest-scoring plate element technique uses a bridge of elements that is constructed through the tangent
point of the Fillet radius such that the thickness of the element matches tile volume of the fillet. This model produces errors of
less than 4.6 percent for static loading and less than 7.4 percent for modal analysis. This simple plate element technique will prove
critical for efficient, timely, and accurate dynamic analysis of complex thin-walled structures.
Author
Fillets; Thin Walls; Dynamic Structural Analysis
20010025828 Air Force Systems Command, Eglin AFB, FL USA
Informal: Technical Information Report for Underground Storage Tank Sites
April 1992; 98p; In English
Contract(s)/Grant(s): F33615-90-D-4014
Report No.(s): AD-A384611; No Copyright; Avail: CASI; A02, Microfiche; A05, Hardcopy
As part of an on-going Installation Restoration Program (IRP) at Eglin AFB, Florida ten Underground Storage Tank Sites
are being investigated to determine if contamination is present in the groundwater at these sites. Previous remediation efforts at
these sites have included removal of the tanks and off-site bioremediation of contaminated soils. This is an Informal Technical
Information Report (ITIR) presenting the analytical results and pertinent field data gathered during the investigation effort.
DTIC
Contamination; Ground Water; Soils
20010026195 Monash Univ., Dept. of Mechanical Engineering, Clayton, Australia
Special issue: Experimental Validation of Theoretical Predictions for Composites Structures
Marshall, I. H., Editor, Monash Univ., Australia; Jones, R., Editor; Kim, Thomas D., Editor; Composite Structures; Jan. 08, 2001;
ISSN 0263-8223; Volume 50, No. 4; 126p; In English; Composites Structures, 18-19 Nov. 1999, Melbourne, Australia
Contract(s)/Grant(s): F62562-99-M-9218
Report No.(s): AD-A386167; AOARD-CSP-99-08; Copyright; Avail: Issuing Activity
Conference Proceedings to Include the Following: ”Experience With the Finite Element Modelling of a Full-Scale Test of
a Composite Aircraft Control Surface” ”Material Characterization of Laminated Composite Plates Via Static Testing” ”Evaluating
the Soundness of Bonding Using Shearography” ”Combined Numerical-Experimental Model for the Identification of Mechanical
Properties of Laminated Structures” ”Control of Beam Vibrations by Means of Piezoelectric Devices: Theory and Experiments”
”Impact Energy Absorption Characteristics of Composite Structures” ”Experimental and Computer Natural Frequencies of
Square Pultruded GRP Plates: Effects of Anisotropy, Hole Size Ratio, and Edge Support Conditions” ”Optical Fibre Sensors for
45