A new designed quasi-3D needled felt C/ C composites have been tested to measure both in-plane
shear and interlaminar shear properties by the Iosipescu shear method. The results of both stresses and moduli have
shown small scatter,and invalid failure modes were obtained. The interlaminar shear V鄄notch specimen was analyzed
using the finite element method to find out how the stress and strain fields distribute in the test section. The study
shows that,the stress concentrations near the notch roots have caused premature failures of the sample. When two
cracks were introduced, a homogeneous shear stress state was achieved.