A Systematic Characterization Approach for Vacuum Bag Only Prepregs towards an Accurate Process Design

Area of Science:

• Materials Science
• Aerospace Engineering
• Composite Manufacturing

Background:

• Aerospace-grade composite parts require precise manufacturing processes.
• Vacuum Bag Only (VBO) prepregs offer an efficient manufacturing route.
• Process design, modeling, and validation are critical for VBO quality.

Purpose of the Study:

• To introduce a systematic material characterization approach for VBO prepregs.
• To integrate material properties with VBO process mechanisms (fluid flow, consolidation, heat transfer).
• To provide essential material data for robust VBO process design and modeling.

Main Methods:

• Characterization categorized into resin system, fiber architecture, and thermal behavior.
• Empirical models developed for resin cure-kinetics, glass transition temperature, and viscosity.
• X-ray tomography used to determine fiber architecture and air permeability.
• Novel specimen preparation for experimental characterization of specific heat capacity and thermal conductivity.

Main Results:

• Established empirical models for resin system properties.
• Quantified fiber architecture and air permeability using X-ray tomography.
• Experimentally determined thermal characteristics (specific heat capacity, thermal conductivity).
• Integrated material data suitable for process modeling.

Conclusions:

• A systematic characterization methodology for VBO prepregs has been successfully developed.
• The approach effectively integrates material properties with critical process mechanisms.
• This methodology provides the necessary data for robust and validated VBO process design in aerospace composite manufacturing.