Composite Materials and Structures

DURATION: TWO DAYS
COURSE NO.: 1030

Carbon fiber-reinforced polymer matrix composites (PMCs) and carbon matrix composites (CAMCs) - especially carbon/carbon composites (CCCs) - are well-established in spacecraft and launch vehicle structures and subsystems.  Metal matrix composites (MMCs) and ceramic matrix composites (CMCs) are used in selective applications, including electronic/photonic thermal management.  Low-CTE advanced materials with thermal conductivities of 1700 W/m-K are in production, resulting in mass reductions of as much as 85%.  The key driving force for use of composites in structures is that they offer up to order-of-magnitude improvements in specific stiffness (stiffness-to-density) and specific strength (strength-to-density) ratios, combined with outstanding resistance to fatigue and creep. The near-zero thermal distortion achievable with composites has led to their widespread application in antennas, optical benches, instruments and other components requiring dimensional stability.  CAMCs, and CMCs offer significant mass reductions for high-temperature applications.  This course provides an overview of all these important materials.  It emphasizes an understanding of the basic principles that can prevent some of the well-publicized failures and problems in recent years.  Participants are invited to bring issues for class discussion.

COURSE MATERIALS:
Include an extensive set of notes..

Spacecraft and launch vehicle engineers, scientists and managers involved in structures, mechanisms, propulsion, antennas, solar arrays, optical systems, thermal management and electronic/photonic packaging. The course is intended for those who have had little or no experience with composite and those with experience who wish to broaden their knowledge of materials of special interest to launch vehicles and spacecraft. Quality assurance and manufacturing engineers. Purchasing specialists. Material suppliers. Other professionals who need a knowledge of composites technology.

Properties of the four classes of composite materials: PMCs, MMCs, CMCs and CAMCs (which includes CCCs). Dimensionally stable composites. High temperature materials. Ultrahigh-thermal-conductivity composites and other advanced materials. Properties of the many different types of carbon (graphite) fibers. Other key fibers. Special resins for space applications. The importance of test methods. How to design composite components. Manufacturing methods, including low-cost processes. Avoiding common pitfalls. Special considerations for the space environment. Microcracking.  How to choose from the wide array of composite materials. Current and emerging applications in structures, mechanisms, optical benches instrument structures, solar arrays, antennas, booms and masts, propulsion systems, thermal control, electronic packaging and electronic enclosures

1. Introduction.
   Overview. Brief history. Key classes of composite materials: PMCs, MMCs, CMCs, CAMCs and CCCs. Terminology. Importance of anisotropy.
2. Key Materials and Their Properties.
   Fibrous reinforcements: carbon (graphite) made from polyacrylonitrile (PAN), petroleum and coal tar pitch, aramid, E-glass, high strength glass, boron, silicon carbide, alumina and others. Particulate reinforcements. Key resin systems: epoxies, cyanate esters (polycyanurates), siloxanes, bismaleimides, polyimides and others. Test method considerations. Properties of key PMCs, MMCs, CMCs, CAMCs and CCCs: strength properties, elastic properties, thermal expansion, thermal conductivity, moisture expansion, and density. Property variability.
3. Special Considerations for Spacecraft and Launch Vehicle Applications.
   Microcracking, outgassing, EMI and ionizing radiation shielding, atomic oxygen degradation. Improving oxidation resistance of CCCs.
4. Manufacturing Methods and Nondestructive Evaluation.
   Key fabrication methods for PMCs, MMCs, CMCs, CAMCs and CCCs. Low cost processes. Overview of key NDE methods.  Outsourcing issues.
5. Design Methods.
   Special design considerations for composite materials: anisotropic strength and elastic properties, low transverse properties, stress concentrations, Microcracking. Laminated plate theory. Adhesive and mechanical joints. Lessons learned.
6. Applications.
   Spacecraft structures, launch vehicle structures, optical benches, instrument structures, solar arrays, antennas, booms and masts, propulsion systems, thermal control, electronic packaging, mechanisms.