FATIGUE OF SANDWICH STRUCTURES WITH INSERTS

The main purpose of the study was to evaluate fatigue in sandwich stru ctures with inserts. Cross-linked PVC foam with closed cells as the co re material was used in this investigation because this foam type has gained widespread use for maritime applications. Fatigue tests for a f our-point bending test on a sandwich-beam containing an insert were in vestigated using numerical fatigue calculations in addition to the fin ite element method. A small crack initiated in the numerical model was propagated by reducing the stiffness of the finite elements at the cr ack tip. The J-integral was used when estimating the energy release ra te. The stiffness of the insert material was used as a design paramete r. It was seen from the investigation that the stiffness of the insert material had almost no influence on the fatigue crack propagation. (C ) 1998 Published by Elsevier Science Ltd. All rights reserved.