MMI Joins the Composite Center!

The transfer to MSU of the Polymer Composites Laboratory (PCL), a major lab owned by the Midland-based Michigan Molecular Institute (MMI), was approved June 11 by the MSU Board of Trustees. The PCL will now be called the Advanced Materials Laboratory, an MSU Engineering Experiment Station (AMEES).

"By joining forces, we will have the largest integrated facility for composites research, development and prototype processing in a non-industrial environment in the country," said Lawrence T. Drzal, director of MSU's Composite Materials and Structures Center.

Closer ties between MMI, a premier research institute conducting advanced education, research, and development in the fields of polymer science and technology, and MSU will benefit both organizations, Drzal said, as their strengths complement one another.

"Our strength is composites processing. The PCL's strength is material performance and both of us are strong in material development," he said.

MMI Board of Directors Chairman Herbert D. Doan feels, "Together we can promote more effective polymer science and technology in the mid-Michigan region, and increase our state's competitiveness in this important technological area."

MMI was founded in 1970, funded by three Midland-based foundations -- the Herbert H. and Grace Dow Foundation and the Charles J. Strosacker Foundation. MMI composites staff expertise ranges from basic polymer materials science and pyhsics, to polymer and composite processing and performance to materials development and characterization capability as well. The applied programs at MMI address research topics including high temperature polymers, advanced methods for producing polymers and polymer composites to novel structural designs. These projects are funded by a wide range of companies from the aerospace to the durable goods industries as well as federal agencies from all departments of the federal government.

The efforts of the 10 person staff at the MMI facility will be directed at: composite materials research independently as well as in collaboration with MSU faculty and staff; advanced development work under governement and industry contract; and proprietary research for industry.

The merging of MSU and MMI composites activities creates a unique inter-institutional strength. Not only are the personnel complimentary (30+ faculty and 80+ students at MSU with 10 staff at MMI) in their research and education, but the facilities at both institutions (14,000 square feet at MMI and 7,500 square feet at MSU) offer a critical combination of analytical, processing and characterization equipment equalling the finest facilities in the country at either an academic or industrial site.

This combination will provide the critical mass of talents to be even more successful in the competition for regional and national grants as well as to more quickly transfer the latests research results into the private sector. It will aid in the transfer of technology from academia to industry through the utilization of existing resources to the greatest degree possible with direct short and long term benefits to MSU as well as to the people of Michigan. The net result is that MSU will have moved into a prominent position as a major contributor to the advancement of polymers and polymer composite materials for durable goods applications.

Technology Reinvestment Project

The Composite Materials and Structures Center has submitted a proposal in hopes of joining the Technology Reinvestment Project (TRP). This project, administered by the Defense Technology Conversion Council (DTCC) and chaired by the Advanced Research Projects Agency (ARPA), strives to stimulate the transition to a growing, integrated, national industrial capability which provides the most advanced, affordable, military systems and the most competitive commercial products. TRP programs are structured to expand high quality employment opportunities in commercial and dual-use United States industries and demonstrably enhance U.S. competitiveness. This will be accomplished through the application of defense and commercial resources to develop dual-use technologies, manufacturing and technology assistance to small firms, and education and training programs that enhance U.S. manufacturing skills and target displaced industry workers.

The Advanced Research Projects Agency (ARPA) of the Department of Defense, the Department of Energy/Defense Programs (DOE/DP), the Department of Commerce's National Institute of Standards and Technology (NIST), the National Science Foundation (NSF), and the National Aeronautics and Space Administration (NASA), are collaborating in the Technology Reinvestment Project to execute the programs authorized under the Defense Conversion, Reinvestment, and Transition Assistance Act of Fiscal Year 1993 and other legislation. The TRP is administered by the Defense Technology Conversion Council (DTCC), chaired by the ARPA and will conducta future solicitation of proposals. Funding for TRP activities will be cost shared with non-Federal Government entities.

The TRP strategy is to invest funds in activities which: 1) Develop technologies which enable new products and processes 2) Deploy existing technology into commercial and military products and processes 3) Stimulate the integration of military and commercial research and production activities. Eleven broad areas have been identified as key dual-use technologies for development in the Technology Development activity area.

These topics were judged to have the highest priority based on future growth potential, military need and commercial opportunities. Materials/Structures Manufacturing is one of these eleven areas, where advanced composites and innovative forming technologies are of interest. Specifically, polymer matrix composites, metal matrix composites, carbon-carbon composites, ceramic matrix composites, adaptive (smart) composites and structures, process modeling, and in-situ sensing have been identified as key dual-use technologies.

Employment Opportunity

The army tank command (future home of the National Automotive Center) in Warren, Michigan, has a possibility of an opening or two for civilian engineers with experience and interest in processing along with some knowledge of mechanics. The starting date could range from now until the Fall.

If you are interested reply by FAX to Mr. Jamie Florence, FAX: (313) 574-8904.

Upcoming Conferences and Seminars

In order to increase communications between the Composites Materials and Structures Center and its various members, we would like to inform you of upcoming conferences and seminars pertaining to your research areas. Here is a list of some conferences which might be of interest, and deadlines for papers presented at those conferences. Brochures on these conferences are available at the Composites Center. Please contact Margie Gray at (517) 353-5466 for any requests.

EDUCOM - 8th Annual Summer Meeting - Educational Uses of Information Technology (EUIT) Program

Location: Snowmass, Colorado

Dates: 8/4-6/93

American Chemical Society - 28th Intersociety Energy Conversion Engineering Conference

Location: Atlanta, Georgia

Dates: 8/8-13/93

American Institute of Chemical Engineers

Location: Seattle, Washington

Dates: 8/15-18/93

Paper due: 1/15/93

International Joint Conference on Artificial Intelligence - '93

Location: Chambery, France

Dates: 8/29-9/3/93

Paper due: 11/1/92

First Biomass Conference of The Americas: Energy, Environment, Agriculture, and Industry - (Provides a national and international forum to support the development of a viable biomass industry.)

Location: Burlington, Vermont

Dates: 8/30-9/2/93

Abstract due: 3/1/93

Paper due: 6/1/93

International Conference of Coal Science - 7th Annual Conference (coals potential and environmental knowledge)

Location: Bannff, Alberta, Canada

Dates: 9/12-17/92

Paper due: 12/31/92

Army Research Office - First Workshop on Smart Structure (will be presenting ARO sponsored research)

Location: The University of Arlington, Arlinton, Texas

Dates: 9/22-24/93

Center for Chemical Process Safety of the American Institute of Chemical Engineers - Process Safety Management Conference and Workshop

Location: San Francisco, California

Dates: 9/22-24/93

American Society for Composites -8th Technical Conference of Composite Materials - (All types of composites such as polymeric composites, metal matrix composite, etc....)

Location: Cleveland, Ohio

Dates: 10/19-21/93

Abstract due: 1/15/93

Paper due: 6/15/93

Society for American Manufacturers and Processing Engineers - 14th International European Conference/Expo

Location: Birmingham, England

Dates: 10/19-21/93

Society for The Advancement of Material and Process Engineering - 25th International Technical Conference/Tabletops.

Location: Philadelphia, Pennsylvania

Dates: 10/26-28/92

U.S. Department of Energy - Tenth International Symposium on Alcohol Fuels (Examines scientific and technical advances for the use and production of alcohol fuels)

Location: Colorado Springs, Colorado

Dates: 11/7-10/93

Abstract due: 3/31/93

Paper due: 7/15/93

The 9th Annual ASM/ESD Advanced Composite Conference and Exposition

Location: Dearborn, Michigan

Dates: 11/8-11/93

Abstract due: 4/23/93

Paper due: 5/6/93

Materials Research Society -Technical Symposia, Short Courses, Equipment Exhibit and Table-Top Display (Each symposium will provide a forum for scientists and engineers to exchange information and ideas at the forefront of materials research.)

Location: Boston, Massachusettes

Dates: 11/29-12/3/93

Paper due: 6/20/93

Society of Manufacturing Engineers - "Tooling for Composites '94" Conference and Exhibit

Location: Anaheim, California

Dates: 1/17-20/94

Abstract due: 4/26/93

Engineering Foundation - Advances in Bipolymer Engineering

Location: Palm Coast, Florida

Dates: 1/23-28/94

Abstract due: 6/15/93

American Institute of Chemical Engineers - National Meeting - Application of Supercritical Fluids

Location: Atlanta, California

Dates: 4/17-21/94

Abstract due: 8/1/93

The National Science Foundation and the Defense Logistics Agency - Conference on Computer Integrated Manufacturing in the Process Industries

Location: Rutgers University, New Brunswick, New Jersey

Dates: 5/1-5/94

Abstract due: 8/1/93

Non-Linear Random Vibration of Filamentary Composite Plates

R. Harichandran (Associate Professor, Civil & Environmental Engineering), M. Naja (Graduate Student, Civil & Environmental Engineering)

In recent years composite materials are being widely used in a number of applications. Due to their high strength to weight and stiffness to weight ratios, advanced technology filamentary composite laminates (such as glass, boron or graphite filaments with epoxy matrices) have made a substantial impact in the aerospace industry over the last two decades, and are now also being promoted in automobile, railroad, ocean engineering and other industries. Although the components built of composites until now have been relatively minor ones, the charge given to NASA to develop high-speed civil aircraft capable of carrying about 350 passengers and achieving a speed of 2.4 Mach, indicates that entire aircraft bodies may soon be built of composite materials. Similar ventures are underway in other transportation industries. The composite components used in many of these areas are predominantly exposed to stochastic dynamic loads. While the analysis and design of aircraft and automobile components has historically been performed using deterministic dynamic analysis, recent advances in random vibration analysis allows more realistic techniques to be used. Space vehicle and aircraft components made for NASA and the military are more and more being designed for random loads. Major finite element package developers have started to address these needs by incorporating capabilities for such analysis in their codes. However, very little work has been done on the random vibration analysis of elements made of composites, which display strongly anisotropic and moderately non-linear behavior. There is an important need to address this deficiency; to develop suitable techniques for the random vibration analysis of composite structures, and to incorporate these techniques into general purpose finite element codes so that they may be widely used in analysis and design.

One of the most important differences that filamentary composite laminates have over traditional materials (such as aluminum and steel) used in aircraft, automobiles, rail cars, ships, etc., is their anisotropic behavior. Another important feature is that the stress-strain relations exhibit significant non-linearities even for modest loads, when the loading is not parallel to the filaments or when the loading involves shear.

Exact non-linear random vibration analysis is possible only for very simple structural systems. For complex systems, approximate methods must be used. Of several available approximate methods, the method of equivalent linearization is best suited within the finite element framework and has been adopted for our study. A cubic variation for the shear strain-stress law, which was proposed based on experiments, has been used to model the softening behavior under shear. At present, the formulation has been developed for laminated plates modeled using classical plate theory. The analysis involves an iterative procedure, in which each iteration consists of a linear random vibration analysis. The element stiffness and mass matrices are computed and assembled using the finite element formulation, and in every iteration, the stiffness matrix is updated to reflect the stress sensitive nature of the material. Root-mean-square displacements, strains and stresses are computed at the end of the analysis when the iterations have converged.

While the classical laminate theory based on Kirchoff's hypothesis is a starting point, it is known that the effects of transverse shear strains and normal strain in the thickness direction causes significant deviations from this theory for composite plates having a very high ratio of in-plane modulus to transverse shear modulus. Following the initial first-order shear deformation theories, a number of improved theories have been proposed in recent times. The next phase of this work will include higher-order shear theories, develop parallel algorithms that will enable the intensive computations to be performed efficiently on parallel computers, and extend the formulations to include shell elements.

Latex-Modified Steel Fiber Reinforced Concrete Composites

P. Soroushian (Professor, Civil & Environmental Engineering),
A Tlili(Research Assistant, Civil & Environmental Engineering)

Ordinary concrete has a few disadvantages such as low tensile and flexural strengths, large drying shrinkage, and high permeability. It fails in a brittle manner under tensile stress systems and impact loads. These deficiencies generally result from the ease of initiation and propagation of microcracks, and also from the lack of post-cracking tensile resistance in conventional concrete materials. Steel fiber reinforcement and polymer modification of concrete materials each can overcome some of these problems with conventional concrete.

Steel fibers are highly effective in enhancing the post-peak ductility and energy absorption capacity of concrete under tensile stress systems. The stabilization of macrocracks by steel fibers in concrete results in major improvements in the compressive and flexural ductility, energy absorption capacity, flexural strength, and impact resistance of concrete. Nevertheless, steel fibers do present problems with the workability and flowability of the resulting fresh mixture, in addition to the development of microcracks at fiber-cement matrix interfaces.

Latex polymer modification, on the other hand, improves the impermeability as well as strength and ductility characteristics of concrete. Latex polymers in the presence of steel fibers do overcome the damage to the workability of the mix associated with fiber reinforcement and also provide for a better bonding between fibers and the concrete matrix because of the formation of a monolithic polymer film that surrounds the fibers, fills the smaller voids, and links the cementitious environment to the fibers. As a result, the formation of many of the microcracks that tend to take place along the fiber-matrix interface is prevented. In addition, the resistance of fibers against pull-out action is further enhanced, resulting in improved flexural strength, toughness characteristics, and impact resistance. The figure shows typical flexural load-deflection curves for four different concretes types: plain (i.e., unmodified, unreinforced), latex-modified, steel fiber reinforced, and latex-modified steel fiber reinforced. The improvements in strength and toughness resulting from latex modification and steel fiber reinforcement, and the desirable joint effects of latex polymers and steel fibers, are obvious in this figure. Experimental results have also shown that latex polymers can substantially enhance the impermeability and corrosion protection potentials of steel fiber reinforced concrete.

In short, steel fibers and latex polymers are very compatible for joint application to concrete. Significant improvements in the mechanical, physical and durability properties of concrete have been achieved through the combined use of steel fibers and latex polymers.

Flexural Load-Deflection

The Effect of Surface Sulfonation on the Organic Vapor Barrier Properties of Orientated Polypropylene

R. Gavara (Visiting Scholar, Packaging),
J.R. Giacin (Professor, Packaging),
R.J. Hernandez (Assistant Professor, Packaging),
K. Wangwiwatslip (Research Assistant, Packaging)

Surface Sulfonation of Oriented Polypropylene

A series of oriented polypropylene film samples were sulfonated in an attempt to achieve improvement of their barrier properties. Polypropylene film samples (6" x 13") were treated for 60, 90, 120 and 180 seconds, respectively at an S03 concentration of approximately 1.0% (v/v).

Following the sulfonation step, the films were removed from the sulfonation reactor and neutralized by immersion in a 5% aqueous ammonium hydroxide solution.

Surface Analysis

The surface sulfonated oriented polypropylene films were analyzed by x-ray photoelectron spectroscopy (XPS) to determine the levels of sulfonation achieved for the respective film samples.

Ethyl Acetate Permeation Measurements

For permeability studies, the vapor generator system and cells were maintained at a constant temperature of 25 +/- 1o C. The penetrant vapor concentrations are expressed throughout in ppm (mass/volume) vapor in nitrogen, where 1 ppm equals 1 ug ethyl acetate per cm3 of gas mixture at 1 atm and 21 o C.

A quasi-isostatic test procedure with gas chromatography analysis was employed and is described in detail elsewhere (Hernandez et al., 1986). At predetermined time intervals, a 100 ul sample of headspace was removed from the low concentration cell chambers with a gas tight syringe and injected directly into the GC. The withdrawn sample was replaced by an equal amount of pure nitrogen in order to maintain a constant total pressure (1 atm).

The permeation process was carried out until a steady-state flux was attained. In this method, the high and low concentration cell chambers and the test film were maintained at a constant temperature and pressure throughout the period of test.

The permeability values P obtained for the sulfonated polypropylene sample are summarized in Table 1. Also presented are the effective diffusion coefficient D and solubility S values. The levels of sulfonation are expressed as sample exposure time and atomic percent of sulfur to show the effect of sulfonation on the organic vapor barrier properties of the oriented polypropylene test film.

From the results presented in Table 1, it appears that for the polypropylene film sulfonated to a level of approximately 6 atomic % sulfur, surface sulfonation resulted in nearly a one order of magnitude reduction in the transmission rate of ethyl acetate.

Sorption Studies for Toluene Vagor

Sorption studies were carried out using a Cahn-2000 electrobalance with toluene vapor as the sorbate. Typical sorption studies were carried out at 21 +/- 1o C, at a toluene vapor activity of approximately 0.035. Unless otherwise indicated, all films were neutralized with NH4+ cation. Film samples investigated included:

1. oriented polypropylene film;
2. sulfonated polypropylene film (60 sec);
3. sulfonated polypropylene film (90 sec) and
4. sulfonated polypropylene film (120 sec).

The effect of sulfonation on the sorption of toluene vapor is summarized graphically in Figure 1, where the respective sorption curves are plotted as a function of run time.

The permeability parameters obtained from the sorption studies are summarized in Table 2. As shown, for the polypropylene film sulfonated for 120 sec with 1% S03 , sulfonation had a significant effect on the transport properties of toluene vapor. A three order of magnitude reduction in the permeability coefficient was obtained, when compared to the toluene permeability coefficient of the untreated control, at similar test conditions.

The relationship between the permeability parameters, P, D, and S and the extent of sulfonation, expressed as contact time, is presented graphically in Figure 2. From these studies it was concluded that the reduction in P, as a function of sulfonation time, resulted from a reduction in the mobility term, D. The solubility coefficient remains fairly constant following sulfonation, as compared to the solubility coefficient of the untreated control.

References:

R.J. Hernandez, A.L. Baner, and J.R. Giacin. J. of Plastic Film & Sheeting 2(3):187- 211, 1986.

Calendar of Events

July

International Microwave Power Institute - 28th International Microwave Symposium & Professional Development Courses: Quality Enhancements Using Microwaves

Location: Montreal, Canada

Dates: 7/11-14/93

American Association for Artificial Intelligence - ' 93

Location: Washington, D.C.

Dates: 7/11-16/93

9th International Conference on Composite Materials - Industrial Exhibition

Location: Madrid, Spain

Dates: 7/12-16/93

National Science Foundation Undergraduate Faculty Enhancement Program: Concurrent Engineering and Design for Manufacture program. (Program designed to familiarize engineering undergraduate faculty to important developments in engineering)

Location: Fort Collins, Colorado

Dates: 7/26-30/93

Composite Materials and Structures Center
College of Engineering
Michigan State University
East Lansing, MI 48824-1326

Please send any comment or request to

CompositeWEB page