Course Length: 5 days

Pre Requisites:

None - This course is a prerequisite for subsequent manufacturing and repair courses.

Summary:

Our most popular class, Advanced Composite Structures: Fabrication & Damage Repair-Phase 1 is designed to meet the needs of a wide range of personnel; from the novice to the seasoned professional.

This course is a prerequisite for both our repair and manufacturing programs and is highly recommended to anyone seeking a better understanding of advanced composite materials, processes, layup/lamination, vacuum bagging, adhesive bonding, tooling, repair, and inspection methods and techniques.

Introduction:

Balanced with theoretical and practical presentations, the hands-on exercises in this course are extensive; they will work with prepreg carbon fiber unidirectional tape to explore the effects of orientation; “balance” and “symmetry” in a laminate.

The students will also work with dry glass fabric and liquid epoxy resin in an exercise designed to teach fundamental vacuum bagging, bleeder & breather concepts.

Mid-week, teams work with prepreg glass and aramid fiber harness-satin fabrics, along with Nomex® honeycomb and polyurethane foam core materials, making sandwich panel structures, utilizing laminate “nesting” techniques.

And finally, basic repair methods and techniques will be presented along with performing a “wet layup” repair in the lab. On the last day, the final repaired part will be cut in half for evaluation of the manufactured and repaired panel.

Topics:

Key Lecture Elements:

  • History of composites, recent developments and terminology.
  • Introduction to advanced composite materials/structures.
  • Resin/adhesive systems: thermosets vs. thermoplastics, mix ratios, viscosity, service temperature limits, cold storage requirements/shelf life limits, pot life, etc.
  • Material Forms: dry cloth and wet resins vs. prepregs, weave/styles, etc.
  • Fundamentals of Fabrication: prepreg cloth handling, ply orientation, layup procedures, vacuum bagging.
  • Fabrication Methods: wet layup, prepreg layup, filament winding, RTM, infusion, press molding, pultrusion as well as automated tape layup (ATL) and fiber placement (AFP).
  • Curing methods: oven/autoclave/hot bonder cures. Viscoelastic properties.
  • Health and Safety Issues: proper handling, personal protection, allergic reactions, waste disposal.
  • Introduction to adhesive bonding technology: co-curing vs. secondary bonding, surface preparation, cleanliness, bond line thickness and clamping pressure requirements.
  • Principles of Tooling: types of tools, thermal characteristics of various tooling materials.
  • Drilling and fastening; proper speed and feed requirements, use of mechanical and adhesive bonded fasteners.
  • Primer on repair design; permanent vs. temporary repairs, scarf vs. stepped vs. mechanical patch repair scenarios. Inspection methods & techniques: non-destructive inspection methods, defect detection, documentation, acceptable vs. unacceptable defects, defect prevention.

Workshop Exercises:

  • Panel layup using prepreg carbon uni-tape materials; symmetric and asymmetric laminates.
  • Panel layup using dry glass cloth and liquid epoxy resin materials. Vacuum bagging with varied bleeder/breather sequences to evaluate resin bleed and flow characteristics.
  • Sandwich panel layup, bagging and processing of nested glass and aramid fiber fabric foam and honeycomb core panels.
  • Vacuum bagging using non-autoclave bleeder/breather schedules. Installation of pleats to minimize bridging in high-angle core transitions. Vacuum debulking, leak checking, and identification of other potential bagging problems.
  • Oven curing; vacuum, ramp rate, soak, and cooling requirements.
  • Composite repair; damage removal, scarf preparation, core and skin repair using wet layup materials and processes.
  • Introduction to hot-bond repair equipment; demonstration of bonders, heat blankets and thermocouple placement.