Composite Materials

· Measurements of debonding may be used to determine the fiber-matrix interactions. The diagram shows two configurations: (a) to measure the interfacial shear strength, and (b) to measure the normal tensile strength of the interface.
· When (a) is loaded in compression with a stress σ_c, the different elastic response of the matrix and the fiber gives rise to a shear stress, τ_s= 2.5σ_c.

· Measuring the applied stress at which debonding can just be detected gives the interfacial shear strength.

From: Hull, "Introduction to Composite Materials," Cambridge (1992)