On the Dynamic Tensile Behaviour of Thermoplastic Composite Carbon/Polyamide 6.6 Using Split Hopkinson Pressure Bar

Area of Science:

• Materials Science
• Mechanical Engineering
• Composite Materials

Background:

• Non-crimp fabric (NCF) thermoplastic composites offer advanced material properties.
• Understanding strain-rate sensitivity is crucial for predicting composite behavior under dynamic loads.
• T700 carbon/polyamide 6.6 is a relevant material system for high-performance applications.

Purpose of the Study:

• To experimentally determine the strain-rate dependent tensile strength of T700 carbon/polyamide 6.6 NCF composites.
• To develop and validate a finite element (FE) model for predicting composite behavior under dynamic loading.
• To enhance the understanding of NCF thermoplastic composite performance under high strain-rate conditions.

Main Methods:

• Dynamic tensile experiments using a split Hopkinson pressure bar (SHPB) at strain rates of 700, 1400, and 2100/s.
• Quasi-static tensile testing for baseline comparison.
• Development and validation of a dynamic FE model using LS-DYNA^®.

Main Results:

• Tensile strength increased by 3.5%, 24.2%, and 45.1% at strain rates of 700, 1400, and 2100/s, respectively.
• The FE model accurately predicted experimental results, validating its predictive capabilities.
• Demonstrated significant strain-rate sensitivity in the T700/polyamide 6.6 composite.

Conclusions:

• The SHPB test provides critical data for characterizing the dynamic mechanical behavior of NCF thermoplastic composites.
• The validated FE model can predict composite performance under various high strain-rate loading scenarios, including impacts.
• This research enhances the understanding and application of T700/polyamide 6.6 composites in dynamic engineering environments.