NASA Scientific and Technical Aerospace Reports

mimic signal processing in biological nerve cells. One approach uses a continuous sensor formed by a series connection of
piezoelectric sensor nodes and a local signal processor to detect damage. The other uses an array type of sensor with
appropriate electronics for quantifying damage. Modeling of wave propagation in simple structural elements was performed
and the electrical responses of the sensors were simulated. Coupon specimens and panels were also instrumented with the two
types of sensors and tested in the laboratory. The simulation and experimental results both confirmed the advantages offered
by these sensors for structural health monitoring applications. A prototype of the acoustic emission local processor was also
fabricated, and detailed specifications for implementing the algorithms developed in this project into an embeddable VLSI chip
are provided. This project resulted in two U.S. patent applications, of which one has already been granted, and two invention
disclosures. Commercialization of this technology is currently being pursued.
DTIC
Composite Materials
20040073724 Minnesota Univ., Minneapolis, MN
Assembly of Functional Porous Solids in Complex Hybrid Composites
Stein, Andreas; Schroden, Rick; Al-Daous, Mohammed; Yu, Dan; Sokolov, Sergey; Mar. 19, 2004; 66 pp.; In English;
Original contains color illustrations
Contract(s)/Grant(s): DAAD19-01-1-0512
Report No.(s): AD-A422640; ARO-41714.10-CH; No Copyright; Avail: CASI; A04, Hardcopy
Three-dimensionally ordered macroporous (3DOM) materials with periodic arrays of solid walls possess interesting
optical, photonic and reactive properties of interest for camouflage, sensing, sorption, and controlled release. These materials
are prepared by colloidal crystal templating techniques. This project was aimed at developing methods for functionalizing
3DOM solids, improving their processibility into shaped structures, forming polymer composites with 3DOM solids,
optimizing their optical properties, and evaluating their mechanical properties. Methods were developed for preparing 3DOM
oxides and hybrid materials as particles on a multiple gram scale, as supported films, monoliths, and composites with polymers
and binders. 3DOM oxides were functionalized with monomeric and polymeric surface groups and with inorganic
nanoparticles. 3DOM particles were optimized for optical effects, including tunable colors and control of color intensity. The
mechanical properties of the highly porous materials were evaluated by depth sensing indentation, and a parameter was
described that allows comparison of mechanical strengths of these materials. Combinations of templating and surface
modification methods permitted the preparation of multifunctional systems that combined optical effects with sorption and
photocatalytic properties. Other applications that were investigated included adsorption of toxic heavy metals, reactivity of
bioactive glass compositions, and a bifunctional catalyst system.
DTIC
Hybrid Composites; Porosity; Porous Materials; Solids; Sorption
20040073741 Delaware Univ., Newark, DE
Dynamic Punch Shear Behavior of Unidirectional and Plain Weave S-2 Glass/ SC15 Composites
Ren, Libo; Gama, Bazle A.; Gillespie, John W., Jr.; Yen, Chian-Fong; Mar. 2004; 36 pp.; In English; Original contains color
illustrations
Contract(s)/Grant(s): DAAD19-01-2-0005
Report No.(s): AD-A422660; ARL-CR-535; No Copyright; Avail: CASI; A03, Hardcopy
Dynamic punch shear behavior of unidirectional and plain weave S-2 Glass/ SC15 epoxy composites is presented. An
incident bar and a transmission tube assembly in compression split-Hopkinson Bar setup is used for the dynamic punch shear
study. Dispersion correction methodology is used with "3-wave" analysis to convert the experimental bar data into
dynamic load-displacement curves. A methodology for determining the average transverse shear strength of the composite
laminates is described. The average transverse shear strength of unidirectional and plain weave composites as a function of
displacement is presented.
DTIC
Dynamic Characteristics; Fiber Composites; Glass
20040074325 NASA Langley Research Center, Hampton, VA, USA
High Temperature Transfer Molding Resins: Preliminary Composite Properties of PETI-375
Connell, J. W.; Smith, J. G., Jr.; Hergenrother, P. M.; Criss, J. M., Jr.; January 08, 2004; 12 pp.; In English; SAMPE 2004
Symposium and Exhibition, 16-20 May 2004, Long Beach, CA, USA
Contract(s)/Grant(s): 757-01-00; Copyright; Avail: CASI; A03, Hardcopy
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