Numerical Calculation of the Aircraft Skin with Multi-Site Damage

Numerical Calculation of the Aircraft Skin with Multi-Site Damage The presence of the multi-site damage (MSD) in an aircraft structure can result in catastrophic damage when the residual strength is not sufficient to sustain operational loads. In this paper the influence of the MSD crack size on the residual strength was examined. As a crack criterion the crack tip opening angle (CTOA) was applied in the numerical simulation of the stable tearing. The CTOA criterion was implemented in the commercial software, the MSC.Marc, by means of additional user subroutines. The verification of this implementation was carried out and the obtained results are consistent with those presented in literature. The influence of the MSD crack size was determined for two crack scenarios: with a leading crack and without one.