Tensile and Interfacial Mechanical Properties for Single Aramid III Fibers under Dynamic Loading

Area of Science:

• Materials Science
• Composite Materials
• Mechanical Engineering

Background:

• The interface between fibers and resin is critical for composite performance.
• Accurate dynamic testing of single fiber-resin interfaces is challenging.

Purpose of the Study:

• To enhance the mini split Hopkinson tension bar (SHTB) for dynamic mechanical testing of single fiber/resin interfaces.
• To evaluate the effect of surface modification on Aramid III fiber/resin interfacial properties.

Main Methods:

• Modified single Aramid III fibers using a polyamine treatment (Catechol-Tetraethylenepentamine).
• Conducted quasi-static and dynamic tensile tests using an electronic tensile testing machine and mini SHTB.
• Employed the microdroplet method with mini SHTB to measure dynamic interfacial shear strength (IFSS).

Main Results:

• Surface modification had a negligible effect on the tensile properties of individual Aramid III fibers.
• Dynamic IFSS of the modified Aramid III fiber/waterborne polyurethane resin interface increased from 36.16 MPa to 41.51 MPa.
• SEM analysis revealed regular grid structures on debonded fibers, indicating improved interfacial adhesion.

Conclusions:

• The enhanced mini SHTB is effective for dynamic interfacial testing.
• Polyamine surface modification enhances the dynamic interfacial shear strength of Aramid III fiber/resin composites.
• The observed grid structures contribute to improved interfacial performance by preventing debonding.