This paper presents the 3-D failure analysis and design for the shape of carbon/carbon brake disk which is safe to the failure. The mechanical properties of the carbon/carbon composites were measured for both in-plane and out of plane directions. The mechanical properties were used as the input of the 3-D failure analysis of the brake disk. The gap between rotor clip and clip retainer was an important parameter in the loading transfer mechanism of the disk. The change of gap was considered separating the mechanical deformation and thermal deformation. Because the rotor clips and clip retainers were not contacted, the clip retainers and rivets were excluded from the analysis model. The disk was modeled by using the cyclic symmetry condition and the contact problem between the rotor disk and rotor clip was considered.
From the results of the 3-D stress analysis, the stress concentration at the key hole of the brake disk was confirmed. The stress distributions were studied as the rotation angle of the contact surface and the radius of curvature at the key hole part vary.
