Test methodHigh rate test method for fiber-matrix interface characterization

A new test method to directly characterize fiber-matrix interface properties under high rate of loading has been developed. A tensile Hopkinson bar with a modified incident bar is used to load a microdroplet test specimen. Numerical simulations were carried out to design the test specimen geometry and validate data reduction procedures for the dynamic interface experiments. Stress wave propagation in an S-2 Glass/Epoxy microdroplet specimen was studied with different droplet sizes (100 μm-200 μm) and fiber gage lengths (2 mm-6 mm). Simulation results indicate that dynamic equilibrium can be maintained up to a displacement rate of 10 m/s. Dynamic microdroplet experiments were conducted at a displacement rate of 1 m/s on S-2 glass/epoxy interface. Experimental results and post-failure inspection of the fiber matrix interface showed that the new test method is effective in measuring high rate interface properties of composites.