A direct complex stress function approach for modelling stiffened panels containing multiple site damage

The analysis of stiffened panel structures containing multiple site damage (MSD) is addressed through the complex variable method, in association with the requirement for displacement compatibility. The method is extended by replacing the usual single crack stress and displacement functions by those for a series of arbitrary straight collinear cracks which are used to mode l exactly the main and secondary crack damage in the sheet. It is shown tha t the problem can be reduced to a system of linear equations for the unknow n forces at the attachment points between the sheet and the stiffener from which the stress intensity factor of the collinear cracks can be determined . The stress intensity factor and the attachment force distribution are det ermined for several configurations and compared with those from numerically based approaches. (C) 1999 Elsevier Science B.V. All rights reserved.